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  • Adobe Reader process fails when starting second instance

    - by Reddog
    In our C# WinForms application, we generate PDF files and launch Adobe Reader (or whatever the default system .pdf handler is) via the Process class. Since our PDF files can be large (approx 200K), we handle the Exited event to then clean up the temp file afterwards. The system works as required when a file is opened and then closed again. However, when a second file is opened (before closing Adobe Reader) the second process immediately exits (since Reader is now using it's MDI powers) and in our Exited handler our File.Delete call should fail because it's locked by the now joined Adobe process. However, in Reader we instead get: There was an error opening this document. This file cannot be found. The unusual thing is that if I put a debugger breakpoint before the file deletion and allow it to attempt (and fail) the deletion, then the system behaves as expected! I'm positive that the file exists and fairly positive that all handles/file streams to the file are closed before starting the process. We are launching with the following code: // Open the file for viewing/printing (if the default program supports it) var pdfProcess = new Process(); pdfProcess.StartInfo.FileName = tempFileName; if (pdfProcess.StartInfo.Verbs.Contains("open", StringComparer.InvariantCultureIgnoreCase)) { var verb = pdfProcess.StartInfo.Verbs.First(v => v.Equals("open", StringComparison.InvariantCultureIgnoreCase)); pdfProcess.StartInfo.Verb = verb; } pdfProcess.StartInfo.Arguments = "/N"; // Specifies a new window will be used! (But not definitely...) pdfProcess.SynchronizingObject = this; pdfProcess.EnableRaisingEvents = true; pdfProcess.Exited += new EventHandler(pdfProcess_Exited); _pdfProcessDictionary.Add(pdfProcess, tempFileName); pdfProcess.Start(); Note: We are using the _pdfProcessDictionary to store references to the Process objects so that they stay in scope so that Exited event can successfully be raised. Our cleanup/exited event is: void pdfProcess_Exited(object sender, EventArgs e) { Debug.Assert(!InvokeRequired); var p = sender as Process; try { if (_pdfProcessDictionary.ContainsKey(p)) { var tempFileName = _pdfProcessDictionary[p]; if (File.Exists(tempFileName)) // How else can I check if I can delete it!!?? { // NOTE: Will fail if the Adobe Reader application instance has been re-used! File.Delete(tempFileName); _pdfProcessDictionary.Remove(p); } CleanOtherFiles(); // This function will clean up files for any other previously exited processes in our dictionary } } catch (IOException ex) { // Just swallow it up, we will deal with trying to delete it at another point } } Possible solutions: Detect that the file is still open in another process Detect that the second process hasn't really been fully exited and that the file is opened in the first process instead

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  • Look over my C# SQLite Query, what am I doing wrong?

    - by CODe
    I'm writing a WinForms database application using SQLite and C#. I have a sqlite query that is failing, and I'm unsure as to where I'm going wrong, as I've tried everything I could think of. public DataTable searchSubs(String businessName, String contactName) { string SQL = null; if ((businessName != null && businessName != "") && (contactName != null && contactName != "")) { // provided business name and contact name for search SQL = "SELECT * FROM SUBCONTRACTOR WHERE BusinessName LIKE %@BusinessName% AND Contact LIKE %@ContactName%"; } else if ((businessName != null && businessName != "") && (contactName == null || contactName == "")) { // provided business name only for search SQL = "SELECT * FROM SUBCONTRACTOR WHERE BusinessName LIKE %@BusinessName%"; } else if ((businessName == null || businessName == "") && (contactName != null && contactName != "")) { // provided contact name only for search SQL = "SELECT * FROM SUBCONTRACTOR WHERE Contact LIKE %@ContactName%"; } else if ((businessName == null || businessName == "") && (contactName == null || contactName == "")) { // provided no search information SQL = "SELECT * FROM SUBCONTRACTOR"; } SQLiteCommand cmd = new SQLiteCommand(SQL); cmd.Parameters.AddWithValue("@BusinessName", businessName); cmd.Parameters.AddWithValue("@ContactName", contactName); cmd.Connection = connection; SQLiteDataAdapter da = new SQLiteDataAdapter(cmd); DataSet ds = new DataSet(); try { da.Fill(ds); DataTable dt = ds.Tables[0]; return dt; } catch (Exception e) { MessageBox.Show(e.ToString()); return null; } finally { cmd.Dispose(); connection.Close(); } } I continually get an error saying that it is failing near the %'s. That's all fine and dandy, but I guess I'm structuring it wrong, but I don't know where! I tried adding apostrophes around the "like" variables, like this: SQL = "SELECT * FROM SUBCONTRACTOR WHERE Contact LIKE '%@ContactName%'"; and quite honestly, that is all I can think of. Anyone have any ideas?

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  • Are the old httpHandlers and httpModules elements needed in IIS7?

    - by James Newton-King
    I'd like to clean up the web.config and remove unneeded XML. A default ASP.NET 3.5 web application has the follow elements in the web.config: <httpHandlers> <remove verb="*" path="*.asmx"/> <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" validate="false"/> </httpHandlers> <httpModules> <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/> <add name="UrlRoutingModule" type="System.Web.Routing.UrlRoutingModule, System.Web.Routing, Version=3.5.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" /> </httpModules> When running under IIS7, which has modules and handlers being registered under the system.webServer element, is the configuration above still needed?

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  • OutOfMemory during paging

    - by Tony
    Hi I am using ObjectDataSource, ListView, CustomPaging If the total number of rows is too big, I got OutOfMemory exception, it seems that it caused by some array, I don't get it, because total number of rows should never make any array to be filled with elements, the page size do!! This is the logger. ****EXCEPTION # 3 : 4/30/2010 9:43:07 PM System.Web.HttpUnhandledException: Exception of type 'System.Web.HttpUnhandledException' was thrown. --- System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown. at System.Web.UI.WebControls.ListView.CreateChildControls() at System.Web.UI.Control.EnsureChildControls() at System.Web.UI.WebControls.ListView.get_Controls() at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) at System.Web.UI.Control.LoadViewStateRecursive(Object savedState) at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) at System.Web.UI.Control.LoadViewStateRecursive(Object savedState) at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) at System.Web.UI.Control.LoadViewStateRecursive(Object savedState) at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) at System.Web.UI.Control.LoadViewStateRecursive(Object savedState) at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) at System.Web.UI.Control.LoadViewStateRecursive(Object savedState) at System.Web.UI.Control.LoadChildViewStateByIndex(ArrayList childState) at System.Web.UI.Control.LoadViewStateRecursive(Object savedState) at System.Web.UI.Page.LoadAllState() at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) --- End of inner exception stack trace --- at System.Web.UI.Page.HandleError(Exception e) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest() at System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) at System.Web.UI.Page.ProcessRequest(HttpContext context) at ASP.default_aspx.ProcessRequest(HttpContext context) in c:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\Temporary ASP.NET Files\flickrdemo\15752207\c63ea96c\App_Web__8yxn9sb.0.cs:line 0 at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

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  • Setup of high-end web server and DB server cluster on Amazon EC2: Is this how it's done?

    - by user1086584
    Amazon is so technical, I want to confirm that my understanding is correct. We have a large 500 GB database. (OrientDB.) We will have it mirrored to one another in the same Availability Zone. We believe the database size will grow rapidly. The plan is: Get 4 large instances that are compatible types with Placement Groups (as well as ideally, Enhanced Networking) (2 for web, 2 for DB.) We use an EBS-backed instances to store our operating system. Discussion here: http://alestic.com/2012/01/ec2-ebs-boot-recommended We can set up ephemeral SSD instance storage as swap space. (But it is lost after even a reboot. I hear its hard to add ephemeral storage if booting from EBS, but possible.) For offsite backup, we will take periodic snapshots and store them on S3. Obviously we need to ensure the database is in a safe state when that snapshot happens to avoid corruption. (Any hints here, aside from shutting down the DB?) If the database gets too big, we need to create a EBS volume that's larger. We can use RAID to break the 1 TB limit: http://alestic.com/2009/06/ec2-ebs-raid Static assets on web servers will be stored on S3. Is that correct? Or am I missing something?

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  • How to hide subfolder when using Web.config for subdomains?

    - by mc-kay
    I have FTP access to my ASP.NET Websapce (IIS 7) and I route subdomains with a Web.config in the web root folder. She looks like this: <?xml version="1.0" encoding="UTF-8"?> <configuration> <system.webServer> <rewrite> <rules> <rule name="route www and emtpy requests" stopProcessing="true"> <match url=".*" /> <conditions logicalGrouping="MatchAll" trackAllCaptures="false"> <add input="{HTTP_HOST}" pattern="^(www.)?example.com" /> <add input="{PATH_INFO}" pattern="^/www/" negate="true" /> </conditions> <action type="Rewrite" url="\www\{R:0}" /> </rule> <rule name="route to blog" stopProcessing="true"> <match url=".*" /> <conditions logicalGrouping="MatchAll" trackAllCaptures="false"> <add input="{HTTP_HOST}" pattern="^blog.example.com$" /> <add input="{PATH_INFO}" pattern="^/blog/" negate="true" /> </conditions> <action type="Rewrite" url="\blog\{R:0}" /> </rule> </rules> </rewrite> </system.webServer> </configuration> As you can see i have two folders in my root directory: "www" and "blog". When i now enter "blog.example.com" everythink is working fine, but when i click a link i will go to "blog.example.com/blog" What can I do to prevent this behavior ?

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  • How to Log Into a Web App Simultaneously with Different Account?

    - by Ngu Soon Hui
    I want to log into a web application, using at least ten account names at one single point of time ( I am not trying to do anything illegal, so don't worry). AFAIK, each tab in Chrome will share the same session, therefore, for one machine, one can use Google Chrome to log in at most 2 accounts, one in normal mode, another in Incognito mode. Is there anyway I can log into multiple accounts? I know I can open up IE and Firefox ( probably Safari etc) and login, but this is not really scalable as the number of web browsers is finite. Edit: My application is a localhost application; it resides on my computer. So proxy may not be that useful, and you now probably understand why it's nothing illegal. Edit2: CookieSwap seems like a good idea, but the problem is that once I swap the cookie, all the tabs and the FF apps' cookie are swap as well. Can the swapping be done on a tab basis or on application basis, so that on a dual-monitor, I can see the different login side-by-side?

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  • How should I deploy my JVM-based web application on ubuntu?

    - by Pieter Breed
    I've developed a web application using clojure/compojure (JVM based) and while developing I tested it using embedded jetty that runs on 0.0.0.0:8080. I would now like to deploy it to run on port 80 on ubuntu. I do dynamic virtual hosting, so any request for any host that arrives on port 80 should be handled by my application. The issues that worries me are: I can still run it embedded but I'm worried about running my app as root (needed for binding to port 80). I'm not sure if I can 'give up root' when in the JVM. Do I need to be concerned by this? besides, serving web applications is a known problem and I should be using known solutions for this (jetty or tomcat) but especially tomcat seems very heavy weight. Besides, I only have one application that listens to /* and does routing internally. (with compojure/ring). What I'm trying to say with this is that tomcat by default assigns WARs to subfolders which I don't want. So basically what I need is some very safe way of binding to port 80 on ubuntu that can with minimal interference send all requests to my app. Any ideas?

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  • .NET WebRequest.PreAuthenticate not quite what it sounds like

    - by Rick Strahl
    I’ve run into the  problem a few times now: How to pre-authenticate .NET WebRequest calls doing an HTTP call to the server – essentially send authentication credentials on the very first request instead of waiting for a server challenge first? At first glance this sound like it should be easy: The .NET WebRequest object has a PreAuthenticate property which sounds like it should force authentication credentials to be sent on the first request. Looking at the MSDN example certainly looks like it does: http://msdn.microsoft.com/en-us/library/system.net.webrequest.preauthenticate.aspx Unfortunately the MSDN sample is wrong. As is the text of the Help topic which incorrectly leads you to believe that PreAuthenticate… wait for it - pre-authenticates. But it doesn’t allow you to set credentials that are sent on the first request. What this property actually does is quite different. It doesn’t send credentials on the first request but rather caches the credentials ONCE you have already authenticated once. Http Authentication is based on a challenge response mechanism typically where the client sends a request and the server responds with a 401 header requesting authentication. So the client sends a request like this: GET /wconnect/admin/wc.wc?_maintain~ShowStatus HTTP/1.1 Host: rasnote User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3 (.NET CLR 4.0.20506) Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Language: en,de;q=0.7,en-us;q=0.3 Accept-Encoding: gzip,deflate Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 Keep-Alive: 300 Connection: keep-alive and the server responds with: HTTP/1.1 401 Unauthorized Cache-Control: private Content-Type: text/html; charset=utf-8 Server: Microsoft-IIS/7.5 WWW-Authenticate: basic realm=rasnote" X-AspNet-Version: 2.0.50727 WWW-Authenticate: Negotiate WWW-Authenticate: NTLM WWW-Authenticate: Basic realm="rasnote" X-Powered-By: ASP.NET Date: Tue, 27 Oct 2009 00:58:20 GMT Content-Length: 5163 plus the actual error message body. The client then is responsible for re-sending the current request with the authentication token information provided (in this case Basic Auth): GET /wconnect/admin/wc.wc?_maintain~ShowStatus HTTP/1.1 Host: rasnote User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3 (.NET CLR 4.0.20506) Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8 Accept-Language: en,de;q=0.7,en-us;q=0.3 Accept-Encoding: gzip,deflate Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7 Keep-Alive: 300 Connection: keep-alive Cookie: TimeTrakker=2HJ1998WH06696; WebLogCommentUser=Rick Strahl|http://www.west-wind.com/|[email protected]; WebStoreUser=b8bd0ed9 Authorization: Basic cgsf12aDpkc2ZhZG1zMA== Once the authorization info is sent the server responds with the actual page result. Now if you use WebRequest (or WebClient) the default behavior is to re-authenticate on every request that requires authorization. This means if you look in  Fiddler or some other HTTP client Proxy that captures requests you’ll see that each request re-authenticates: Here are two requests fired back to back: and you can see the 401 challenge, the 200 response for both requests. If you watch this same conversation between a browser and a server you’ll notice that the first 401 is also there but the subsequent 401 requests are not present. WebRequest.PreAuthenticate And this is precisely what the WebRequest.PreAuthenticate property does: It’s a caching mechanism that caches the connection credentials for a given domain in the active process and resends it on subsequent requests. It does not send credentials on the first request but it will cache credentials on subsequent requests after authentication has succeeded: string url = "http://rasnote/wconnect/admin/wc.wc?_maintain~ShowStatus"; HttpWebRequest req = HttpWebRequest.Create(url) as HttpWebRequest; req.PreAuthenticate = true; req.Credentials = new NetworkCredential("rick", "secret", "rasnote"); req.AuthenticationLevel = System.Net.Security.AuthenticationLevel.MutualAuthRequested; req.UserAgent = ": Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3 (.NET CLR 4.0.20506)"; WebResponse resp = req.GetResponse(); resp.Close(); req = HttpWebRequest.Create(url) as HttpWebRequest; req.PreAuthenticate = true; req.Credentials = new NetworkCredential("rstrahl", "secret", "rasnote"); req.AuthenticationLevel = System.Net.Security.AuthenticationLevel.MutualAuthRequested; req.UserAgent = ": Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3 (.NET CLR 4.0.20506)"; resp = req.GetResponse(); which results in the desired sequence: where only the first request doesn’t send credentials. This is quite useful as it saves quite a few round trips to the server – bascially it saves one auth request request for every authenticated request you make. In most scenarios I think you’d want to send these credentials this way but one downside to this is that there’s no way to log out the client. Since the client always sends the credentials once authenticated only an explicit operation ON THE SERVER can undo the credentials by forcing another login explicitly (ie. re-challenging with a forced 401 request). Forcing Basic Authentication Credentials on the first Request On a few occasions I’ve needed to send credentials on a first request – mainly to some oddball third party Web Services (why you’d want to use Basic Auth on a Web Service is beyond me – don’t ask but it’s not uncommon in my experience). This is true of certain services that are using Basic Authentication (especially some Apache based Web Services) and REQUIRE that the authentication is sent right from the first request. No challenge first. Ugly but there it is. Now the following works only with Basic Authentication because it’s pretty straight forward to create the Basic Authorization ‘token’ in code since it’s just an unencrypted encoding of the user name and password into base64. As you might guess this is totally unsecure and should only be used when using HTTPS/SSL connections (i’m not in this example so I can capture the Fiddler trace and my local machine doesn’t have a cert installed, but for production apps ALWAYS use SSL with basic auth). The idea is that you simply add the required Authorization header to the request on your own along with the authorization string that encodes the username and password: string url = "http://rasnote/wconnect/admin/wc.wc?_maintain~ShowStatus"; HttpWebRequest req = HttpWebRequest.Create(url) as HttpWebRequest; string user = "rick"; string pwd = "secret"; string domain = "www.west-wind.com"; string auth = "Basic " + Convert.ToBase64String(System.Text.Encoding.Default.GetBytes(user + ":" + pwd)); req.PreAuthenticate = true; req.AuthenticationLevel = System.Net.Security.AuthenticationLevel.MutualAuthRequested;req.Headers.Add("Authorization", auth); req.UserAgent = ": Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3 (.NET CLR 4.0.20506)"; WebResponse resp = req.GetResponse(); resp.Close(); This works and causes the request to immediately send auth information to the server. However, this only works with Basic Auth because you can actually create the authentication credentials easily on the client because it’s essentially clear text. The same doesn’t work for Windows or Digest authentication since you can’t easily create the authentication token on the client and send it to the server. Another issue with this approach is that PreAuthenticate has no effect when you manually force the authentication. As far as Web Request is concerned it never sent the authentication information so it’s not actually caching the value any longer. If you run 3 requests in a row like this: string url = "http://rasnote/wconnect/admin/wc.wc?_maintain~ShowStatus"; HttpWebRequest req = HttpWebRequest.Create(url) as HttpWebRequest; string user = "ricks"; string pwd = "secret"; string domain = "www.west-wind.com"; string auth = "Basic " + Convert.ToBase64String(System.Text.Encoding.Default.GetBytes(user + ":" + pwd)); req.PreAuthenticate = true; req.Headers.Add("Authorization", auth); req.UserAgent = ": Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3 (.NET CLR 4.0.20506)"; WebResponse resp = req.GetResponse(); resp.Close(); req = HttpWebRequest.Create(url) as HttpWebRequest; req.PreAuthenticate = true; req.Credentials = new NetworkCredential(user, pwd, domain); req.UserAgent = ": Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3 (.NET CLR 4.0.20506)"; resp = req.GetResponse(); resp.Close(); req = HttpWebRequest.Create(url) as HttpWebRequest; req.PreAuthenticate = true; req.Credentials = new NetworkCredential(user, pwd, domain); req.UserAgent = ": Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.3) Gecko/20090824 Firefox/3.5.3 (.NET CLR 4.0.20506)"; resp = req.GetResponse(); you’ll find the trace looking like this: where the first request (the one we explicitly add the header to) authenticates, the second challenges, and any subsequent ones then use the PreAuthenticate credential caching. In effect you’ll end up with one extra 401 request in this scenario, which is still better than 401 challenges on each request. Getting Access to WebRequest in Classic .NET Web Service Clients If you’re running a classic .NET Web Service client (non-WCF) one issue with the above is how do you get access to the WebRequest to actually add the custom headers to do the custom Authentication described above? One easy way is to implement a partial class that allows you add headers with something like this: public partial class TaxService { protected NameValueCollection Headers = new NameValueCollection(); public void AddHttpHeader(string key, string value) { this.Headers.Add(key,value); } public void ClearHttpHeaders() { this.Headers.Clear(); } protected override WebRequest GetWebRequest(Uri uri) { HttpWebRequest request = (HttpWebRequest) base.GetWebRequest(uri); request.Headers.Add(this.Headers); return request; } } where TaxService is the name of the .NET generated proxy class. In code you can then call AddHttpHeader() anywhere to add additional headers which are sent as part of the GetWebRequest override. Nice and simple once you know where to hook it. For WCF there’s a bit more work involved by creating a message extension as described here: http://weblogs.asp.net/avnerk/archive/2006/04/26/Adding-custom-headers-to-every-WCF-call-_2D00_-a-solution.aspx. FWIW, I think that HTTP header manipulation should be readily available on any HTTP based Web Service client DIRECTLY without having to subclass or implement a special interface hook. But alas a little extra work is required in .NET to make this happen Not a Common Problem, but when it happens… This has been one of those issues that is really rare, but it’s bitten me on several occasions when dealing with oddball Web services – a couple of times in my own work interacting with various Web Services and a few times on customer projects that required interaction with credentials-first services. Since the servers determine the protocol, we don’t have a choice but to follow the protocol. Lovely following standards that implementers decide to ignore, isn’t it? :-}© Rick Strahl, West Wind Technologies, 2005-2010Posted in .NET  CSharp  Web Services  

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  • SimpleMembership, Membership Providers, Universal Providers and the new ASP.NET 4.5 Web Forms and ASP.NET MVC 4 templates

    - by Jon Galloway
    The ASP.NET MVC 4 Internet template adds some new, very useful features which are built on top of SimpleMembership. These changes add some great features, like a much simpler and extensible membership API and support for OAuth. However, the new account management features require SimpleMembership and won't work against existing ASP.NET Membership Providers. I'll start with a summary of top things you need to know, then dig into a lot more detail. Summary: SimpleMembership has been designed as a replacement for traditional the previous ASP.NET Role and Membership provider system SimpleMembership solves common problems people ran into with the Membership provider system and was designed for modern user / membership / storage needs SimpleMembership integrates with the previous membership system, but you can't use a MembershipProvider with SimpleMembership The new ASP.NET MVC 4 Internet application template AccountController requires SimpleMembership and is not compatible with previous MembershipProviders You can continue to use existing ASP.NET Role and Membership providers in ASP.NET 4.5 and ASP.NET MVC 4 - just not with the ASP.NET MVC 4 AccountController The existing ASP.NET Role and Membership provider system remains supported as is part of the ASP.NET core ASP.NET 4.5 Web Forms does not use SimpleMembership; it implements OAuth on top of ASP.NET Membership The ASP.NET Web Site Administration Tool (WSAT) is not compatible with SimpleMembership The following is the result of a few conversations with Erik Porter (PM for ASP.NET MVC) to make sure I had some the overall details straight, combined with a lot of time digging around in ILSpy and Visual Studio's assembly browsing tools. SimpleMembership: The future of membership for ASP.NET The ASP.NET Membership system was introduces with ASP.NET 2.0 back in 2005. It was designed to solve common site membership requirements at the time, which generally involved username / password based registration and profile storage in SQL Server. It was designed with a few extensibility mechanisms - notably a provider system (which allowed you override some specifics like backing storage) and the ability to store additional profile information (although the additional  profile information was packed into a single column which usually required access through the API). While it's sometimes frustrating to work with, it's held up for seven years - probably since it handles the main use case (username / password based membership in a SQL Server database) smoothly and can be adapted to most other needs (again, often frustrating, but it can work). The ASP.NET Web Pages and WebMatrix efforts allowed the team an opportunity to take a new look at a lot of things - e.g. the Razor syntax started with ASP.NET Web Pages, not ASP.NET MVC. The ASP.NET Web Pages team designed SimpleMembership to (wait for it) simplify the task of dealing with membership. As Matthew Osborn said in his post Using SimpleMembership With ASP.NET WebPages: With the introduction of ASP.NET WebPages and the WebMatrix stack our team has really be focusing on making things simpler for the developer. Based on a lot of customer feedback one of the areas that we wanted to improve was the built in security in ASP.NET. So with this release we took that time to create a new built in (and default for ASP.NET WebPages) security provider. I say provider because the new stuff is still built on the existing ASP.NET framework. So what do we call this new hotness that we have created? Well, none other than SimpleMembership. SimpleMembership is an umbrella term for both SimpleMembership and SimpleRoles. Part of simplifying membership involved fixing some common problems with ASP.NET Membership. Problems with ASP.NET Membership ASP.NET Membership was very obviously designed around a set of assumptions: Users and user information would most likely be stored in a full SQL Server database or in Active Directory User and profile information would be optimized around a set of common attributes (UserName, Password, IsApproved, CreationDate, Comment, Role membership...) and other user profile information would be accessed through a profile provider Some problems fall out of these assumptions. Requires Full SQL Server for default cases The default, and most fully featured providers ASP.NET Membership providers (SQL Membership Provider, SQL Role Provider, SQL Profile Provider) require full SQL Server. They depend on stored procedure support, and they rely on SQL Server cache dependencies, they depend on agents for clean up and maintenance. So the main SQL Server based providers don't work well on SQL Server CE, won't work out of the box on SQL Azure, etc. Note: Cory Fowler recently let me know about these Updated ASP.net scripts for use with Microsoft SQL Azure which do support membership, personalization, profile, and roles. But the fact that we need a support page with a set of separate SQL scripts underscores the underlying problem. Aha, you say! Jon's forgetting the Universal Providers, a.k.a. System.Web.Providers! Hold on a bit, we'll get to those... Custom Membership Providers have to work with a SQL-Server-centric API If you want to work with another database or other membership storage system, you need to to inherit from the provider base classes and override a bunch of methods which are tightly focused on storing a MembershipUser in a relational database. It can be done (and you can often find pretty good ones that have already been written), but it's a good amount of work and often leaves you with ugly code that has a bunch of System.NotImplementedException fun since there are a lot of methods that just don't apply. Designed around a specific view of users, roles and profiles The existing providers are focused on traditional membership - a user has a username and a password, some specific roles on the site (e.g. administrator, premium user), and may have some additional "nice to have" optional information that can be accessed via an API in your application. This doesn't fit well with some modern usage patterns: In OAuth and OpenID, the user doesn't have a password Often these kinds of scenarios map better to user claims or rights instead of monolithic user roles For many sites, profile or other non-traditional information is very important and needs to come from somewhere other than an API call that maps to a database blob What would work a lot better here is a system in which you were able to define your users, rights, and other attributes however you wanted and the membership system worked with your model - not the other way around. Requires specific schema, overflow in blob columns I've already mentioned this a few times, but it bears calling out separately - ASP.NET Membership focuses on SQL Server storage, and that storage is based on a very specific database schema. SimpleMembership as a better membership system As you might have guessed, SimpleMembership was designed to address the above problems. Works with your Schema As Matthew Osborn explains in his Using SimpleMembership With ASP.NET WebPages post, SimpleMembership is designed to integrate with your database schema: All SimpleMembership requires is that there are two columns on your users table so that we can hook up to it – an “ID” column and a “username” column. The important part here is that they can be named whatever you want. For instance username doesn't have to be an alias it could be an email column you just have to tell SimpleMembership to treat that as the “username” used to log in. Matthew's example shows using a very simple user table named Users (it could be named anything) with a UserID and Username column, then a bunch of other columns he wanted in his app. Then we point SimpleMemberhip at that table with a one-liner: WebSecurity.InitializeDatabaseFile("SecurityDemo.sdf", "Users", "UserID", "Username", true); No other tables are needed, the table can be named anything we want, and can have pretty much any schema we want as long as we've got an ID and something that we can map to a username. Broaden database support to the whole SQL Server family While SimpleMembership is not database agnostic, it works across the SQL Server family. It continues to support full SQL Server, but it also works with SQL Azure, SQL Server CE, SQL Server Express, and LocalDB. Everything's implemented as SQL calls rather than requiring stored procedures, views, agents, and change notifications. Note that SimpleMembership still requires some flavor of SQL Server - it won't work with MySQL, NoSQL databases, etc. You can take a look at the code in WebMatrix.WebData.dll using a tool like ILSpy if you'd like to see why - there places where SQL Server specific SQL statements are being executed, especially when creating and initializing tables. It seems like you might be able to work with another database if you created the tables separately, but I haven't tried it and it's not supported at this point. Note: I'm thinking it would be possible for SimpleMembership (or something compatible) to run Entity Framework so it would work with any database EF supports. That seems useful to me - thoughts? Note: SimpleMembership has the same database support - anything in the SQL Server family - that Universal Providers brings to the ASP.NET Membership system. Easy to with Entity Framework Code First The problem with with ASP.NET Membership's system for storing additional account information is that it's the gate keeper. That means you're stuck with its schema and accessing profile information through its API. SimpleMembership flips that around by allowing you to use any table as a user store. That means you're in control of the user profile information, and you can access it however you'd like - it's just data. Let's look at a practical based on the AccountModel.cs class in an ASP.NET MVC 4 Internet project. Here I'm adding a Birthday property to the UserProfile class. [Table("UserProfile")] public class UserProfile { [Key] [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)] public int UserId { get; set; } public string UserName { get; set; } public DateTime Birthday { get; set; } } Now if I want to access that information, I can just grab the account by username and read the value. var context = new UsersContext(); var username = User.Identity.Name; var user = context.UserProfiles.SingleOrDefault(u => u.UserName == username); var birthday = user.Birthday; So instead of thinking of SimpleMembership as a big membership API, think of it as something that handles membership based on your user database. In SimpleMembership, everything's keyed off a user row in a table you define rather than a bunch of entries in membership tables that were out of your control. How SimpleMembership integrates with ASP.NET Membership Okay, enough sales pitch (and hopefully background) on why things have changed. How does this affect you? Let's start with a diagram to show the relationship (note: I've simplified by removing a few classes to show the important relationships): So SimpleMembershipProvider is an implementaiton of an ExtendedMembershipProvider, which inherits from MembershipProvider and adds some other account / OAuth related things. Here's what ExtendedMembershipProvider adds to MembershipProvider: The important thing to take away here is that a SimpleMembershipProvider is a MembershipProvider, but a MembershipProvider is not a SimpleMembershipProvider. This distinction is important in practice: you cannot use an existing MembershipProvider (including the Universal Providers found in System.Web.Providers) with an API that requires a SimpleMembershipProvider, including any of the calls in WebMatrix.WebData.WebSecurity or Microsoft.Web.WebPages.OAuth.OAuthWebSecurity. However, that's as far as it goes. Membership Providers still work if you're accessing them through the standard Membership API, and all of the core stuff  - including the AuthorizeAttribute, role enforcement, etc. - will work just fine and without any change. Let's look at how that affects you in terms of the new templates. Membership in the ASP.NET MVC 4 project templates ASP.NET MVC 4 offers six Project Templates: Empty - Really empty, just the assemblies, folder structure and a tiny bit of basic configuration. Basic - Like Empty, but with a bit of UI preconfigured (css / images / bundling). Internet - This has both a Home and Account controller and associated views. The Account Controller supports registration and login via either local accounts and via OAuth / OpenID providers. Intranet - Like the Internet template, but it's preconfigured for Windows Authentication. Mobile - This is preconfigured using jQuery Mobile and is intended for mobile-only sites. Web API - This is preconfigured for a service backend built on ASP.NET Web API. Out of these templates, only one (the Internet template) uses SimpleMembership. ASP.NET MVC 4 Basic template The Basic template has configuration in place to use ASP.NET Membership with the Universal Providers. You can see that configuration in the ASP.NET MVC 4 Basic template's web.config: <profile defaultProvider="DefaultProfileProvider"> <providers> <add name="DefaultProfileProvider" type="System.Web.Providers.DefaultProfileProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" applicationName="/" /> </providers> </profile> <membership defaultProvider="DefaultMembershipProvider"> <providers> <add name="DefaultMembershipProvider" type="System.Web.Providers.DefaultMembershipProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" applicationName="/" /> </providers> </membership> <roleManager defaultProvider="DefaultRoleProvider"> <providers> <add name="DefaultRoleProvider" type="System.Web.Providers.DefaultRoleProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" applicationName="/" /> </providers> </roleManager> <sessionState mode="InProc" customProvider="DefaultSessionProvider"> <providers> <add name="DefaultSessionProvider" type="System.Web.Providers.DefaultSessionStateProvider, System.Web.Providers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" connectionStringName="DefaultConnection" /> </providers> </sessionState> This means that it's business as usual for the Basic template as far as ASP.NET Membership works. ASP.NET MVC 4 Internet template The Internet template has a few things set up to bootstrap SimpleMembership: \Models\AccountModels.cs defines a basic user account and includes data annotations to define keys and such \Filters\InitializeSimpleMembershipAttribute.cs creates the membership database using the above model, then calls WebSecurity.InitializeDatabaseConnection which verifies that the underlying tables are in place and marks initialization as complete (for the application's lifetime) \Controllers\AccountController.cs makes heavy use of OAuthWebSecurity (for OAuth account registration / login / management) and WebSecurity. WebSecurity provides account management services for ASP.NET MVC (and Web Pages) WebSecurity can work with any ExtendedMembershipProvider. There's one in the box (SimpleMembershipProvider) but you can write your own. Since a standard MembershipProvider is not an ExtendedMembershipProvider, WebSecurity will throw exceptions if the default membership provider is a MembershipProvider rather than an ExtendedMembershipProvider. Practical example: Create a new ASP.NET MVC 4 application using the Internet application template Install the Microsoft ASP.NET Universal Providers for LocalDB NuGet package Run the application, click on Register, add a username and password, and click submit You'll get the following execption in AccountController.cs::Register: To call this method, the "Membership.Provider" property must be an instance of "ExtendedMembershipProvider". This occurs because the ASP.NET Universal Providers packages include a web.config transform that will update your web.config to add the Universal Provider configuration I showed in the Basic template example above. When WebSecurity tries to use the configured ASP.NET Membership Provider, it checks if it can be cast to an ExtendedMembershipProvider before doing anything else. So, what do you do? Options: If you want to use the new AccountController, you'll either need to use the SimpleMembershipProvider or another valid ExtendedMembershipProvider. This is pretty straightforward. If you want to use an existing ASP.NET Membership Provider in ASP.NET MVC 4, you can't use the new AccountController. You can do a few things: Replace  the AccountController.cs and AccountModels.cs in an ASP.NET MVC 4 Internet project with one from an ASP.NET MVC 3 application (you of course won't have OAuth support). Then, if you want, you can go through and remove other things that were built around SimpleMembership - the OAuth partial view, the NuGet packages (e.g. the DotNetOpenAuthAuth package, etc.) Use an ASP.NET MVC 4 Internet application template and add in a Universal Providers NuGet package. Then copy in the AccountController and AccountModel classes. Create an ASP.NET MVC 3 project and upgrade it to ASP.NET MVC 4 using the steps shown in the ASP.NET MVC 4 release notes. None of these are particularly elegant or simple. Maybe we (or just me?) can do something to make this simpler - perhaps a NuGet package. However, this should be an edge case - hopefully the cases where you'd need to create a new ASP.NET but use legacy ASP.NET Membership Providers should be pretty rare. Please let me (or, preferably the team) know if that's an incorrect assumption. Membership in the ASP.NET 4.5 project template ASP.NET 4.5 Web Forms took a different approach which builds off ASP.NET Membership. Instead of using the WebMatrix security assemblies, Web Forms uses Microsoft.AspNet.Membership.OpenAuth assembly. I'm no expert on this, but from a bit of time in ILSpy and Visual Studio's (very pretty) dependency graphs, this uses a Membership Adapter to save OAuth data into an EF managed database while still running on top of ASP.NET Membership. Note: There may be a way to use this in ASP.NET MVC 4, although it would probably take some plumbing work to hook it up. How does this fit in with Universal Providers (System.Web.Providers)? Just to summarize: Universal Providers are intended for cases where you have an existing ASP.NET Membership Provider and you want to use it with another SQL Server database backend (other than SQL Server). It doesn't require agents to handle expired session cleanup and other background tasks, it piggybacks these tasks on other calls. Universal Providers are not really, strictly speaking, universal - at least to my way of thinking. They only work with databases in the SQL Server family. Universal Providers do not work with Simple Membership. The Universal Providers packages include some web config transforms which you would normally want when you're using them. What about the Web Site Administration Tool? Visual Studio includes tooling to launch the Web Site Administration Tool (WSAT) to configure users and roles in your application. WSAT is built to work with ASP.NET Membership, and is not compatible with Simple Membership. There are two main options there: Use the WebSecurity and OAuthWebSecurity API to manage the users and roles Create a web admin using the above APIs Since SimpleMembership runs on top of your database, you can update your users as you would any other data - via EF or even in direct database edits (in development, of course)

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  • Questions about .NET CollectionEditor type

    - by smwikipedia
    Who can tell me the internal working mechanism of a CollectionEditor in plain English? I have implemented every virtual function and step into each of them. Still got no clue of its intended algorithm. I searched the web and found tons of compaints about the CollectionEditor type, and even bugs. I am kind of thinking of the CollectionEditor as a total mess.

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  • Problem in hiding scrollbar of webbrowser control

    - by Royson
    I have web browser control in panel and panel is placed in table layout. i have tried to hide scroll bar by webBrowser.ScrollBarsEnabled = false; but still there is scrollbar are visible. I want to hide it irrespective of page width. User should see page area which are best fitted on panel. How to do this.

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  • WPF/Winform Time Range Selector

    - by wonea
    Hello, I'm looking for a decent WPF or Winform time range selector, much like a home central heating system, where a time range is selectable. http://lhill.com.au/l%20hill%20web%20page%20pictures/time%20clock%202.jpg Is there any GUI libraries or examples available to fulfill this need?

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  • How To Bind ComboBox With ListItems in windows Forms?

    - by hatem gamil
    hi all i want to make a 2 comboBoxes ,the first one shows Hours and the Second Shows minutes but i cant do so in windows application as i have working as a web dev for a while and i forgot so i want to declare listItems then bind it to combo box i want to make it as a custom control so i want some help to tell me how to do that i am using VS 2008 thnxx

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  • Subconic3.0 with winform app

    - by Saif Khan
    Can subsonic 3.0 be used with a winform app? Do I need to add any references to the system.web? If it can be done, how can I exclude certain tables in the DB? Can I use the following whih I am using for subsonic 2.0 <providers> <!--<clear/>--> <add name="TEST" type="SubSonic.SqlDataProvider, SubSonic" connectionStringName="myString" includeTableList="CustomerReference" includeProcedureList=""/> </providers>

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  • Need Help Setting an Image with Transparent Background to Clipboard

    - by AMissico
    I need help setting a transparent image to the clipboard. I keep getting "handle is invalid". Basically, I need a "second set of eyes" to look over the following code. (The complete working project at ftp://missico.net/ImageVisualizer.zip.) This is an image Debug Visualizer class library, but I made the included project to run as an executable for testing. (Note that window is a toolbox window and show in taskbar is set to false.) I was tired of having to perform a screen capture on the toolbox window, open the screen capture with an image editor, and then deleting the background added because it was a screen capture. So I thought I would quickly put the transparent image onto the clipboard. Well, the problem is...no transparency support for Clipboard.SetImage. Google to the rescue...not quite. This is what I have so far. I pulled from a number of sources. See the code for the main reference. My problem is the "invalid handle" when using CF_DIBV5. Do I need to use BITMAPV5HEADER and CreateDIBitmap? Any help from you GDI/GDI+ Wizards would be greatly appreciated. public static void SetClipboardData(Bitmap bitmap, IntPtr hDC) { const uint SRCCOPY = 0x00CC0020; const int CF_DIBV5 = 17; const int CF_BITMAP = 2; //'reference //'http://social.msdn.microsoft.com/Forums/en-US/winforms/thread/816a35f6-9530-442b-9647-e856602cc0e2 IntPtr memDC = CreateCompatibleDC(hDC); IntPtr memBM = CreateCompatibleBitmap(hDC, bitmap.Width, bitmap.Height); SelectObject(memDC, memBM); using (Graphics g = Graphics.FromImage(bitmap)) { IntPtr hBitmapDC = g.GetHdc(); IntPtr hBitmap = bitmap.GetHbitmap(); SelectObject(hBitmapDC, hBitmap); BitBlt(memDC, 0, 0, bitmap.Width, bitmap.Height, hBitmapDC, 0, 0, SRCCOPY); if (!OpenClipboard(IntPtr.Zero)) { throw new System.Runtime.InteropServices.ExternalException("Could not open Clipboard", new Win32Exception()); } if (!EmptyClipboard()) { throw new System.Runtime.InteropServices.ExternalException("Unable to empty Clipboard", new Win32Exception()); } //IntPtr hClipboard = SetClipboardData(CF_BITMAP, memBM); //works but image is not transparent //all my attempts result in SetClipboardData returning hClipboard = IntPtr.Zero IntPtr hClipboard = SetClipboardData(CF_DIBV5, memBM); //because if (hClipboard == IntPtr.Zero) { // InnerException: System.ComponentModel.Win32Exception // Message="The handle is invalid" // ErrorCode=-2147467259 // NativeErrorCode=6 // InnerException: throw new System.Runtime.InteropServices.ExternalException("Could not put data on Clipboard", new Win32Exception()); } if (!CloseClipboard()) { throw new System.Runtime.InteropServices.ExternalException("Could not close Clipboard", new Win32Exception()); } g.ReleaseHdc(hBitmapDC); } } private void __copyMenuItem_Click(object sender, EventArgs e) { using (Graphics g = __pictureBox.CreateGraphics()) { IntPtr hDC = g.GetHdc(); MemoryStream ms = new MemoryStream(); __pictureBox.Image.Save(ms, ImageFormat.Png); ms.Seek(0, SeekOrigin.Begin); Image imag = Image.FromStream(ms); // Derive BitMap object using Image instance, so that you can avoid the issue //"a graphics object cannot be created from an image that has an indexed pixel format" Bitmap img = new Bitmap(new Bitmap(imag)); SetClipboardData(img, hDC); g.ReleaseHdc(); } }

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  • .NET 3.5 Listbox Selected Values (Winforms)

    - by Jimbo
    I am BATTLING to get the selected values (please note VALUES not TEXT) from a Winforms Listbox that has multi-select enabled and has been bound to a database table getting the Name (as DisplayMember) and ID (as ValueMember) - I need the ID of the selected items. The listbox control has properties for SelectedValue to get one of the selected items values, but not for all selected items values. The SelectedItems property returns a Listbox.SelectedObjectCollection from which I cannot seem to extract the VALUES of the items. Please help! Thanks.

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  • WPF Tree doesn't work

    - by phenevo
    Could you tell me why I can't see subItems? I've got winforms apps and I added my wpfusercontrol:ObjectsAndZonesTree ServiceProvider is my webservice. Adn method to get listofcountires with subitems works properly (i get countires, regions from this countires, provinces etc...) ElementHost elementHost = new ElementHost { Width = 150, Height = 50, Dock = DockStyle.Fill, Child = new ObjectsAndZonesTree() }; this.splitContainer3.Panel1.Controls.Add(elementHost); XAML: <TreeView Name="GroupView" Grid.Row="0" Grid.Column="0" ItemsSource="{Binding}"> <TreeView.Resources> <HierarchicalDataTemplate DataType="{x:Type ServiceProvider:Country }" ItemsSource="{Binding Items}"> <TextBlock Text="{Binding Path=Name}" /> </HierarchicalDataTemplate> <DataTemplate DataType="{x:Type ServiceProvider:Region}" > <TextBlock Text="{Binding Path=Name}" /> </DataTemplate> <DataTemplate DataType="{x:Type ServiceProvider:Province}" > <TextBlock Text="{Binding Path=Name}" /> </DataTemplate> </TreeView.Resources> </TreeView> XAML.CS public ObjectsAndZonesTree() { InitializeComponent(); LoadView(); } private void LoadView() { GroupView.ItemsSource = new ServiceProvider().GetListOfObjectsAndZones(); } class Country: public class Country { string _name; [XmlAttribute] public string Name { get { return _name; } set { _name = value; } } string _code; [XmlAttribute] public string Code { get { return _code; } set { _code = value; } } string _continentCode; [XmlAttribute] public string ContinentCode { get { return _continentCode; } set { _continentCode = value; } } public Region[] ListOfRegions { get { return _listOfRegions; } set { _listOfRegions = value; } } private Region[] _listOfRegions; public IList<object> Items { get { IList<object> childNodes = new List<object>(); foreach (var group in this.ListOfRegions) childNodes.Add(group); return childNodes; } } } Class Region: public class Region { private Province[] _listOfProvinces; private string _name; private string _code; public Province[] ListOfProvinces { get { return _listOfProvinces; } set { _listOfProvinces = value; } } public string Name { get { return _name; } set { _name = value; } } public string Code { get { return _code; } set { _code = value; } } public string CountryCode { get { return _countryCode; } set { _countryCode = value; } } private string _countryCode; public IList<object> Items { get { IList<object> childNodes = new List<object>(); foreach (var group in this.ListOfProvinces) childNodes.Add(group); return childNodes; } } } It displays me only list of countires.

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  • Preventing multiple repeat selection of synchronized Controls ?

    - by BillW
    The working code sample here synchronizes (single) selection in a TreeView, ListView, and ComboBox via the use of lambda expressions in a dictionary where the Key in the dictionary is a Control, and the Value of each Key is an Action<int. Where I am stuck is that I am getting multiple repetitions of execution of the code that sets the selection in the various controls in a way that's unexpected : it's not recursing : there's no StackOverFlow error happening; but, I would like to figure out why the current strategy for preventing multiple selection of the same controls is not working. Perhaps the real problem here is distinguishing between a selection update triggered by the end-user and a selection update triggered by the code that synchronizes the other controls ? Note: I've been experimenting with using Delegates, and forms of Delegates like Action<T>, to insert executable code in Dictionaries : I "learn best" by posing programming "challenges" to myself, and implementing them, as well as studying, at the same time, the "golden words" of luminaries like Skeet, McDonald, Liberty, Troelsen, Sells, Richter. Note: Appended to this question/code, for "deep background," is a statement of how I used to do things in pre C#3.0 days where it seemed like I did need to use explicit measures to prevent recursion when synchronizing selection. Code : Assume a WinForms standard TreeView, ListView, ComboBox, all with the same identical set of entries (i.e., the TreeView has only root nodes; the ListView, in Details View, has one Column). private Dictionary<Control, Action<int>> ControlToAction = new Dictionary<Control, Action<int>>(); private void Form1_Load(object sender, EventArgs e) { // add the Controls to be synchronized to the Dictionary // with appropriate Action<int> lambda expressions ControlToAction.Add(treeView1, (i => { treeView1.SelectedNode = treeView1.Nodes[i]; })); ControlToAction.Add(listView1, (i => { listView1.Items[i].Selected = true; })); ControlToAction.Add(comboBox1, (i => { comboBox1.SelectedIndex = i; })); } private void synchronizeSelection(int i, Control currentControl) { foreach(Control theControl in ControlToAction.Keys) { // skip the 'current control' if (theControl == currentControl) continue; // for debugging only Console.WriteLine(theControl.Name + " synchronized"); // execute the Action<int> associated with the Control ControlToAction[theControl](i); } } private void treeView1_AfterSelect(object sender, TreeViewEventArgs e) { synchronizeSelection(e.Node.Index, treeView1); } private void listView1_SelectedIndexChanged(object sender, EventArgs e) { // weed out ListView SelectedIndexChanged firing // with SelectedIndices having a Count of #0 if (listView1.SelectedIndices.Count > 0) { synchronizeSelection(listView1.SelectedIndices[0], listView1); } } private void comboBox1_SelectedValueChanged(object sender, EventArgs e) { if (comboBox1.SelectedIndex > -1) { synchronizeSelection(comboBox1.SelectedIndex, comboBox1); } } background : pre C# 3.0 Seems like, back in pre C# 3.0 days, I was always using a boolean flag to prevent recursion when multiple controls were updated. For example, I'd typically have code like this for synchronizing a TreeView and ListView : assuming each Item in the ListView was synchronized with a root-level node of the TreeView via a common index : // assume ListView is in 'Details View,' has a single column, // MultiSelect = false // FullRowSelect = true // HideSelection = false; // assume TreeView // HideSelection = false // FullRowSelect = true // form scoped variable private bool dontRecurse = false; private void treeView1_AfterSelect(object sender, TreeViewEventArgs e) { if(dontRecurse) return; dontRecurse = true; listView1.Items[e.Node.Index].Selected = true; dontRecurse = false; } private void listView1_SelectedIndexChanged(object sender, EventArgs e) { if(dontRecurse) return // weed out ListView SelectedIndexChanged firing // with SelectedIndices having a Count of #0 if (listView1.SelectedIndices.Count > 0) { dontRecurse = true; treeView1.SelectedNode = treeView1.Nodes[listView1.SelectedIndices[0]]; dontRecurse = false; } } Then it seems, somewhere around FrameWork 3~3.5, I could get rid of the code to suppress recursion, and there was was no recursion (at least not when synchronizing a TreeView and a ListView). By that time it had become a "habit" to use a boolean flag to prevent recursion, and that may have had to do with using a certain third party control.

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  • Why does C# thread die?

    - by JackN
    This is my 1st C# project so I may be doing something obviously improper in the code below. I am using .NET, WinForms (I think), and this is a desktop application until I get the bugs out. UpdateGui() uses Invoke((MethodInvoker)delegate to update various GUI controls based on received serial data and sends a GetStatus() command out the serial port 4 times a second. Thread Read() reads the response from serial port whenever it arrives which should be near immediate. SerialPortFixer is a SerialPort IOException Workaround in C# I found at http://zachsaw.blogspot.com/2010/07/serialport-ioexception-workaround-in-c.html. After one or both threads die I'll see something like The thread 0x1288 has exited with code 0 (0x0). in the debug code output. Why do UpdateGui() and/or Read() eventually die? public partial class UpdateStatus : Form { private readonly byte[] Command = new byte[32]; private readonly byte[] Status = new byte[32]; readonly Thread readThread; private static readonly Mutex commandMutex = new Mutex(); private static readonly Mutex statusMutex = new Mutex(); ... public UpdateStatus() { InitializeComponent(); SerialPortFixer.Execute("COM2"); if (serialPort1.IsOpen) { serialPort1.Close(); } try { serialPort1.Open(); } catch (Exception e) { labelWarning.Text = LOST_COMMUNICATIONS + e; labelStatus.Text = LOST_COMMUNICATIONS + e; labelWarning.Visible = true; } readThread = new Thread(Read); readThread.Start(); new Timer(UpdateGui, null, 0, 250); } static void ProcessStatus(byte[] status) { Status.State = (State) status[4]; Status.Speed = status[6]; // MSB Status.Speed *= 256; Status.Speed += status[5]; var Speed = Status.Speed/GEAR_RATIO; Status.Speed = (int) Speed; ... } public void Read() { while (serialPort1 != null) { try { serialPort1.Read(Status, 0, 1); if (Status[0] != StartCharacter[0]) continue; serialPort1.Read(Status, 1, 1); if (Status[1] != StartCharacter[1]) continue; serialPort1.Read(Status, 2, 1); if (Status[2] != (int)Command.GetStatus) continue; serialPort1.Read(Status, 3, 1); ... statusMutex.WaitOne(); ProcessStatus(Status); Status.update = true; statusMutex.ReleaseMutex(); } catch (Exception e) { Console.WriteLine(@"ERROR! Read() " + e); } } } public void GetStatus() { const int parameterLength = 0; // For GetStatus statusMutex.WaitOne(); Status.update = false; statusMutex.ReleaseMutex(); commandMutex.WaitOne(); if (!SendCommand(Command.GetStatus, parameterLength)) { Console.WriteLine(@"ERROR! SendCommand(GetStatus)"); } commandMutex.ReleaseMutex(); } private void UpdateGui(object x) { try { Invoke((MethodInvoker)delegate { Text = DateTime.Now.ToLongTimeString(); statusMutex.WaitOne(); if (Status.update) { if (Status.Speed > progressBarSpeed.Maximum) { Status.Speed = progressBarSpeed.Maximum; } progressBarSpeed.Value = Status.Speed; labelSpeed.Text = Status.Speed + RPM; ... } else { labelWarning.Text = LOST_COMMUNICATIONS; labelStatus.Text = LOST_COMMUNICATIONS; labelWarning.Visible = true; } statusMutex.ReleaseMutex(); GetStatus(); }); } catch (Exception e) { Console.WriteLine(@"ERROR! UpdateGui() " + e); } } }

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  • weird data-grid-view/crystal-reports behaviour c# winforms

    - by jello
    I have a winforms project which I keep in different versions, each version having its own project folder. All these projects use the same database file, which is copied in each project folder too. So if I run a project, let's say 0.34, and then I try to run 0.35, all the database functions don't work, unless I detach the database in SQL server management studio express. So all the database functions don't work, except the data grid view and/or crystal reports. But then, if I detach the database, and I run any version, all the database functions work, except the data grid view and/or crystal reports. So to recap, when the database functions work (like select), crystal reports doesn't work. But when the database functions don't work because the database is not detached, crystal reports works. weird. any ideas?

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