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  • NHibernate Legacy Database Mappings Impossible?

    - by Corey Coogan
    I'm hoping someone can help me with mapping a legacy database. The problem I'm describing here has plagued others, yet I was unable to find a real good solution around the web. DISCLAIMER: this is a legacy DB. I have no control over the composite keys. They suck and can't be changed no matter much you tell me they suck. I have 2 tables, both with composite keys. One of the keys from one table is used as part of the key to get a collection from the other table. In short, the keys don't fully match between the table. ClassB is used everywhere I would like to avoid adding properties for the sake of this mapping if possible. public class ClassA { //[PK] public string SsoUid; //[PK] public string PolicyNumber; public IList<ClassB> Others; //more properties.... } public class ClassB { //[PK] public string PolicyNumber; //[PK] public string PolicyDateTime; //more properties } I want to get an instance of ClassA and get all ClassB rows that match PolicyNumber. I am trying to get something going with a one-to-many, but I realize that this may technically be a many-to-many that I am just treating as one-to-many. I've tried using an association class but didn't get far enough to see if it works. I'm new to these more complex mappings and am looking for advice. I'm open to pretty much any ideas. Thanks, Corey

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  • How to debug jQuery ajax POST to .NET webservice

    - by Nick
    Hey all. I have a web service that I have published locally. I wrote an HTML page to test the web service. The webservice is expecting a string that will be XML. When I debug the web service from within VS everything works great. I can use FireBug and see that my web service is indeed being hit by they AJAX call. After deploying the web service locally to IIS it does not appear to be working. I need to know the best way to trouble shoot this problem. My AJAX js looks like this: function postSummaryXml(data) { $.ajax({ type: 'POST', url: 'http://localhost/collection/services/datacollector.asmx/SaveSummaryDisplayData', data: { xml: data }, error: function(result) { alert(result); }, success: function(result) { alert(result); } }); The web method looks like so: [WebMethod] public string SaveSummaryDisplayData(string xml) { XmlDocument xmlDocument = new XmlDocument(); xmlDocument.LoadXml(xml); XmlParser parser = new XmlParser(xmlDocument); IModel repository = new Repository(); if(repository.AddRecord("TestData",parser.TestValues)) { return "true"; } return "false"; } } I added the return string to the web method in an attempt to ensure that the web-service is really hit from the ajax. The problem is this: In FF the 'Success' function is always called yet the result is always 'NULL'. And the web method does not appear to have worked (no data saved). In IE the 'Error' function is called and the response is server error: 500. I think (believe it or not) IE is giving me a more accurate indication that something is wrong but I cannnot determine what the issue is. Can someone please suggest how I should expose the specific server error message? Thanks for the help!

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  • NHibernate returning duplicate object in child collections when using Fetch

    - by UpTheCreek
    When doing a query like this (using Nhibernate 2.1.2): ICriteria criteria = session.CreateCriteria<MyRootType>() .SetFetchMode("ChildCollection1", FetchMode.Eager) .SetFetchMode("ChildCollection2", FetchMode.Eager) .Add(Restrictions.IdEq(id)); I am getting multiple duplicate objects in some cartesian fashion. E.g. if ChildCollection1 has 3 elements, and ChildColection2 has 2 elements then I get results with each element in ChildColection1 one duplicated, and each element in ChildColection2 triplicated! This was a bit of a WTF moment for me... So how to do this correctly? Is using SetFetchMode like this only supported when specifying one collection? Am I just using it wrong (I've seen some references to results transformers, but imagined this would be simplier). Is this something that's different in NH3? Update: As per Felice's suggestion, I tried using the DistinctRootEntity transformer, but this is still returning duplicates. Code: ICriteria criteria = session.CreateCriteria<MyRootType>() .SetFetchMode("ChildCollection1", FetchMode.Eager) .SetFetchMode("ChildCollection2", FetchMode.Eager) .Add(Restrictions.IdEq(id)); criteria.SetResultTransformer(Transformers.DistinctRootEntity); return criteria.UniqueResult<MyRootType>();

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  • Windows system monitoring and profiling

    - by Aris
    I have several dozen 64-bit Windows 2003 servers in a high performance environment with very bursty system utilization. I am looking for a tool (or tools) to monitor and analyze system performance (eg, CPU utilization, bandwidth, etc). This tool can either query servers from a central location (SNMP) or require installation of a component on each server. It should poll on a 1-second interval. It should be able to generate pretty graphs which show trends over time. As a nice-to-have, it should be able to send out emails or IMs when certain thresholds are exceeded. The tools I have investigated so far, including Solarwinds and PRTG, are not designed to poll this frequently. They seem to be designed for a ~30-second interval. Solarwinds wouldn't go lower than 3-sec, and PRTG chokes at 1-sec. They both default to 1-min. All three tools seem more focused on outage monitoring and reporting than metric collection. Given the bursty nature of our applications, such infrequent polling would result in a very inaccurate picture of performance. I am considering rolling my own solution using perfmon. This would be a lot of work, and seems like reinventing the wheel. Are there any tools out there that meet my needs?

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  • SQL select descendants of a row

    - by Joey Adams
    Suppose a tree structure is implemented in SQL like this: CREATE TABLE nodes ( id INTEGER PRIMARY KEY, parent INTEGER -- references nodes(id) ); Although cycles can be created in this representation, let's assume we never let that happen. The table will only store a collection of roots (records where parent is null) and their descendants. The goal is to, given an id of a node on the table, find all nodes that are descendants of it. A is a descendant of B if either A's parent is B or A's parent is a descendant of B. Note the recursive definition. Here is some sample data: INSERT INTO nodes VALUES (1, NULL); INSERT INTO nodes VALUES (2, 1); INSERT INTO nodes VALUES (3, 2); INSERT INTO nodes VALUES (4, 3); INSERT INTO nodes VALUES (5, 3); INSERT INTO nodes VALUES (6, 2); which represents: 1 `-- 2 |-- 3 | |-- 4 | `-- 5 | `-- 6 We can select the (immediate) children of 1 by doing this: SELECT a.* FROM nodes AS a WHERE parent=1; We can select the children and grandchildren of 1 by doing this: SELECT a.* FROM nodes AS a WHERE parent=1 UNION ALL SELECT b.* FROM nodes AS a, nodes AS b WHERE a.parent=1 AND b.parent=a.id; We can select the children, grandchildren, and great grandchildren of 1 by doing this: SELECT a.* FROM nodes AS a WHERE parent=1 UNION ALL SELECT b.* FROM nodes AS a, nodes AS b WHERE a.parent=1 AND b.parent=a.id UNION ALL SELECT c.* FROM nodes AS a, nodes AS b, nodes AS c WHERE a.parent=1 AND b.parent=a.id AND c.parent=b.id; How can a query be constructed that gets all descendants of node 1 rather than those at a finite depth? It seems like I would need to create a recursive query or something. I'd like to know if such a query would be possible using SQLite. However, if this type of query requires features not available in SQLite, I'm curious to know if it can be done in other SQL databases.

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  • Using a profile property of type List in .NET Membership

    - by hancock
    Hi, I'm working on a C# Webservice that needs to provide authentication as well as roles and profile management. I need each profile to have a property of type List. The profile section in the web.config looks like this: <profile defaultProvider="MyProfileProvider" enabled="true"> <providers> <remove name="MyProfileProvider"/> <add connectionStringName="MySqlServer" applicationName="MyApp" name="MyProfileProvider" type="System.Web.Profile.SqlProfileProvider" /> </providers> <properties> <add name="Websites" type="System.Collections.Generic.List&lt;String&gt;" serializeAs="Binary"/> </properties> </profile> However, when I start the webservice and try to access that property it returns the following error: System.Configuration.ConfigurationErrorsException: Attempting to load this property's type resulted in the following error: Could not load type 'System.Collections.Generic.List<String>'. (C:\Projects\MyProject\web.config line 58) --- System.Web.HttpException: Could not load type 'System.Collections.Generic.List<String>'. Is there a way to use a generic collection for this purpose?

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  • Perform case-insensitive lookup on an Array in MongoDB?

    - by Hal
    So, I've decided to get my feet wet with MongoDB and love it so far. It seems very fast and flexible which is great. But, I'm still going through the initial learning curve and as such, I'm spending hours digging for info on the most basic things. I've search throughout the MongoDB online documentation and have spent hours Googling through pages without any mention of this. I know Mongo is still quite new (v1.x) so it explains why there isn't much information yet. I've even trying looking for books on Mongo without much luck. So yes, I've tried to RTFM with no luck, so, now I turn to you. I have an Array of various Hashtags nested in each document (ie: #apples, #oranges, #Apples, #APPLES) and I would like to perform a case-insensitive find() to access all the documents containing apples in any case. It seems that find does support some regex with /i, but I can't seem to get this working either. Anyway, I hope this is a quick answer for someone. Here's my existing call in PHP which is case sensitive: $cursor = $collection->find(array( "hashtags" => array("#".$keyword)))->sort(array('$natural' => -1))->limit(10); Help?

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  • COM access to classic ASP intrinsic objects

    - by wrench
    I'm converting a VB6 COM object that works with classic ASP to a c# .Net COM Object Interop_COMSVCS.ObjectContext objContext; Interop_COMSVCS.AppServer objAppServer; objAppServer = null; // need to initialize before using objAppServer = new Interop_COMSVCS.AppServer(); objContext = objAppServer.GetObjectContext(); oApplication = (Interop_ASP.Application)objContext["Application"]; oSession = (Interop_ASP.Session)objContext["Session"]; oResponse = (Interop_ASP.Response)objContext["Response"]; oRequest = (Interop_ASP.Request)objContext["Request"]; oSession works to store local information to.from ASP storage oResponse can do simple writes to the browser BUT any code like oRequest.Cookies["sessionId"] or oResponse.Cookies["sessionId"] doesn't provide any sort of read or write access. Any cast or conversion I trry to do tells me I'm dealing with an empty or null System Object. There doesn't seem to be any sort of syntax to get/set the cookie collection. With COM+ I've seesn soem articles that indcate a switch for Access to ASP Intrinsic Objects -- that seesm to describe my issue, but I'd rather not use COM+. There are also some articles that indicate if I was using ASP.NET I could use HttpContext and HttpRequest/Response, but that's a completely different set of data objects that don't seem to be available with classic ASP. I've been stuck on this fopr a few days. Any help appreciated.

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  • Filtering documents against a dictionary key in MongoDB

    - by Thomas
    I have a collection of articles in MongoDB that has the following structure: { 'category': 'Legislature', 'updated': datetime.datetime(2010, 3, 19, 15, 32, 22, 107000), 'byline': None, 'tags': { 'party': ['Peter Hoekstra', 'Virg Bernero', 'Alma Smith', 'Mike Bouchard', 'Tom George', 'Rick Snyder'], 'geography': ['Michigan', 'United States', 'North America'] }, 'headline': '2 Mich. gubernatorial candidates speak to students', 'text': [ 'BEVERLY HILLS, Mich. (AP) \u2014 Two Democratic and Republican gubernatorial candidates found common ground while speaking to private school students in suburban Detroit', "Democratic House Speaker state Rep. Andy Dillon and Republican U.S. Rep. Pete Hoekstra said Friday a more business-friendly government can help reduce Michigan's nation-leading unemployment rate.", "The candidates were invited to Detroit Country Day Upper School in Beverly Hills to offer ideas for Michigan's future.", 'Besides Dillon, the Democratic field includes Lansing Mayor Virg Bernero and state Rep. Alma Wheeler Smith. Other Republicans running are Oakland County Sheriff Mike Bouchard, Attorney General Mike Cox, state Sen. Tom George and Ann Arbor business leader Rick Snyder.', 'Former Republican U.S. Rep. Joe Schwarz is considering running as an independent.' ], 'dateline': 'BEVERLY HILLS, Mich.', 'published': datetime.datetime(2010, 3, 19, 8, 0, 31), 'keywords': "Governor's Race", '_id': ObjectId('4ba39721e0e16cb25fadbb40'), 'article_id': 'urn:publicid:ap.org:0611e36fb084458aa620c0187999db7e', 'slug': "BC-MI--Governor's Race,2nd Ld-Writethr" } If I wanted to write a query that looked for all articles that had at least 1 geography tag, how would I do that? I have tried writing db.articles.find( {'tags': 'geography'} ), but that doesn't appear to work. I've also thought about changing the search parameter to 'tags.geography', but am having a devil of a time figuring out what the search predicate would be.

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  • LINQ to XML via C#

    - by user70192
    Hello, I'm new to LINQ. I understand it's purpose. But I can't quite figure it out. I have an XML set that looks like the following: <Results> <Result> <ID>1</ID> <Name>John Smith</Name> <EmailAddress>[email protected]</EmailAddress> </Result> <Result> <ID>2</ID> <Name>Bill Young</Name> <EmailAddress>[email protected]</EmailAddress> </Result> </Results> I have loaded this XML into an XDocument as such: string xmlText = GetXML(); XDocument xml = XDocument.Parse(xmlText); Now, I'm trying to get the results into POCO format. In an effort to do this, I'm currently using: var objects = from results in xml.Descendants("Results") select new Results // I'm stuck How do I get a collection of Result elements via LINQ? I'm particularly confused about navigating the XML structure at this point in my code. Thank you!

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  • Treeview does not refresh to show childnode moved from one parent node to another

    - by mike
    I am using the Windows Forms TreeView class which contains a set of TreeNodes. The TreeNodes can have child nodes. I have a root node with 2 sub nodes (Node1 and Node2) Node1 has 2 subnodes (child1 and child2) I have a function that will allow a user to select any node and move it to another node: TreeNode SelectNode = this.TreeView1.SelectedNode; TreeNode DestNode = SelectedNewNode(); //function to select a new node SelectedNode.Remove(); DestNode.Nodes.Add(SelectedNode); this.TreeView1.Refresh(); When this executes, the current selected node (child2) is removed from its current parent (Node1) and added to Node2. However, the Refresh() method of the TreeView control does not show that child2 is under Node2. If I debug it and look at the Nodes collection in the TreeView i do see that child2 is under Node2. Can anyone tell me why the Refresh() method does not redraw the new parent to child mapping? Is there a way to tell the TreeView to redraw with the new mappings?

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  • Implementing BindingList<T>

    - by EtherealMonkey
    I am trying to learn more about BindingList because I believe that it will help me with a project that I am working on. Currently, I have an object class (ScannedImage) that is a subtype of a class (HashedImage) that subtypes a native .Net object (Image). There is no reason why I couldn't move the two subtypes together. I am simply subtyping an object that I had previously constructed, but I will now be storing my ScannedImage object in an RDB (well, not technically - only the details and probably the thumbnail). Also, the object class has member types that are my own custom types (Keywords). I am using a custom datagridview to present these objects, but am handling all changes to the ScannedImage object with my own code. As you can probably imagine, I have quite a few events to handle that occur in these base types. So, if I changed my object to implement INotifyPropertyChanged, would the object collection (implementing BindingList) receive notifications of changes to the ScannedImage object? Also, if Keywords were to implement INotifyPropertyChanged, would changes be accessible to the BindingList through the ScannedImage object? Sorry if this seems rather newbish. I only recently discovered the BindingList and not having formal training in C# programming - am having a difficult time moving forward with this. Also, if anyone has any good reference material, I would be thankful for links. Obviously, I have perused the MSDN Library. I have found a few good links on the web, but it seems that a lot of people are now using WPF and ObservableCollection. My project is based on Winforms and .Net3.5 framework. TIA

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  • NullReferenceException when testing DefaultModelBinder.

    - by Byron Sommardahl
    I'm developing a project using BDD/TDD techniques and I'm trying my best to stay the course. A problem I just ran into is unit testing the DefaultModelBinder. I'm using mspec to write my tests. I have a class like this that I want to bind to: public class EmailMessageInput : IMessageInput { public object Recipient { get; set; } public string Body { get; set; } } Here's how I'm building my spec context. I'm building a fake form collection and stuffing it into a bindingContext object. public abstract class given_a_controller_with_valid_email_input : given_a_controller_context { Establish additional_context = () => { var form = new FormCollection { new NameValueCollection { { "EmailMessageInput.Recipient", "[email protected]"}, { "EmailMessageInput.Body", "Test body." } } }; _bindingContext = new ModelBindingContext { ModelName = "EmailMessageInput", ValueProvider = form }; _modelBinder = new DefaultModelBinder(); }; protected static ModelBindingContext _bindingContext; protected static DefaultModelBinder _modelBinder; } public abstract class given_a_controller_context { protected static MessageController _controller; Establish context = () => { _controller = new MessageController(); }; } Finally, my spec throws an null reference exception when I execute .BindModel() from inside one of my specs: Because of = () => { _model = _modelBinder.BindModel(_controller.ControllerContext, _bindingContext); }; Any clue what it could be? Feel free to ask me for more info, if needed. I might have taken something for granted.

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  • iPhone UI addSubview causing concurrency exception

    - by Eli
    This is really odd... I run my app, and while it is opening and the views are constructing I get: Collection <CALayerArray: 0x124650> was mutated while being enumerated. The code trace goes through the following: main UIApplicationMain -[UIApplication _run] CFRunLoopRunInMode CFRunLoopRunSpecific _UIApplicationHandleEvent -[UIApplication sendEvent:] -[UIApplication handleEvent:withNewEvent:] -[UIApplication _runWithURL:sourceBundleID:] -[UIApplication _performInitilizationWithURL:sourceBundleID:] -[AppDelegate applicationDidFinishLaunching:] +[Controller initializeController] //This is my own function [window addSubview: pauseMenuController.view] //This is the last point of my code it goes through -[UIView(Hierarchy) addSubview:] -[UIView(Internal) _addSubview:positioned:relativeTo:] -[UIView(Hierarchy) _makeSubtreePerformSelector:withObject:] -[UIView(Hierarchy) _makeSubtreePerformSelector:withObject:withObject:copySublayers:] -[UIView(Hierarchy) _makeSubtreePerformSelector:withObject:withObject:copySublayers:] _NSFastEnumerationMutationHandler objc_exception_throw I've run the game lots and lots and lots of times and I've never seen this, then suddenly it popped up. The weird thing is that I'm not creating any other threads (that I know of) until after this code all gets called. It'll be easier for me to debug this if someone can give me some explanation of what might be getting modified while it's being accessed in a UIView. Does it have something to do with adding something to the view while it's already adding something, maybe? Any ideas?

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  • Unable to read in my custom .config section

    - by Pure.Krome
    Hi folks, NOTE: this is very very similar to this SO question, but I need some more help. i'm trying to make the following section in my .config file, but i get an exception when trying to access this section. .config file <configSections> <section name="foos" type="Ackbar.Mvc.Models.Foo.FooCollection, Ackbar.Mvc" requirePermission="false"/> <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler" requirePermission="false" /> </configSections> <foos> <add name="aaa" something="zzz"/> <add name="bbb" something="yyy"/> <add name="ccc" something="xxx"/> </foos> Ok, so this means i need to make two classes classes public class FooCollection : ConfigurationElementCollection { ... with my custom overrides, etc. ... } and public class FooElement : ConfigurationElement { [ConfigurationProperty("Name", IsRequired = true)] public string Name { .. } [ConfigurationProperty("Something ", IsRequired = true)] public string Something { .. } [ConfigurationProperty("IsDefault ", IsRequired = false, DefaultValue = false)] public bool IsDefault { .. } } Kewl. Now, when i do the following .... var whatever = ConfigurationManager.GetSection("foos") is throws the following exception :- An error occurred creating the configuration section handler for foos: Type 'Ackbar.Mvc.Models.Foos.FooCollection' does not inherit from 'System.Configuration.IConfigurationSectionHandler'. Can someone please help me? I don't want to wrap the collection INSIDE a parent section. Cheers :)

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  • Deserialize generic collections - coming up empty

    - by AC
    I've got a settings object for my app that has two collections in it. The collections are simple List generics that contain a collection of property bags. When I serialize it, everything is saved with no problem: XmlSerializer x = new XmlSerializer(settings.GetType()); TextWriter tw = new StreamWriter(@"c:\temp\settings.cpt"); x.Serialize(tw, settings); However when I deserialize it, everything is restored except for the two collections (verified by setting a breakpoint on the setters: XmlSerializer x = new XmlSerializer(typeof(CourseSettings)); XmlReader tr = XmlReader.Create(@"c:\temp\settings.cpt"); this.DataContext = (CourseSettings)x.Deserialize(tr); What would cause this? Everything is pretty vanilla... here's a snippet from the settings object... omitting most of it. The PresentationSourceDirectory works just fine, but the PresentationModules' setter isn't hit: private string _presentationSourceDirectory = string.Empty; public string PresentationSourceDirectory { get { return _presentationSourceDirectory; } set { if (_presentationSourceDirectory != value) { OnPropertyChanged("PresentationSourceDirectory"); _presentationSourceDirectory = value; } } } private List<Module> _presentationModules = new List<Module>(); public List<Module> PresentationModules { get { var sortedModules = from m in _presentationModules orderby m.ModuleOrder select m; return sortedModules.ToList<Module>(); } set { if (_presentationModules != value) { _presentationModules = value; OnPropertyChanged("PresentationModules"); } } }

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  • Code Golf: Quickly Build List of Keywords from Text, Including # of Instances

    - by Jonathan Sampson
    I've already worked out this solution for myself with PHP, but I'm curious how it could be done differently - better even. The two languages I'm primarily interested in are PHP and Javascript, but I'd be interested in seeing how quickly this could be done in any other major language today as well (mostly C#, Java, etc). Return only words with an occurrence greater than X Return only words with a length greater than Y Ignore common terms like "and, is, the, etc" Feel free to strip punctuation prior to processing (ie. "John's" becomes "John") Return results in a collection/array Extra Credit Keep Quoted Statements together, (ie. "They were 'too good to be true' apparently")Where 'too good to be true' would be the actual statement Extra-Extra Credit Can your script determine words that should be kept together based upon their frequency of being found together? This being done without knowing the words beforehand. Example: "The fruit fly is a great thing when it comes to medical research. Much study has been done on the fruit fly in the past, and has lead to many breakthroughs. In the future, the fruit fly will continue to be studied, but our methods may change." Clearly the word here is "fruit fly," which is easy for us to find. Can your search'n'scrape script determine this too? Source text: http://sampsonresume.com/labs/c.txt Answer Format It would be great to see the results of your code, output, in addition to how long the operation lasted.

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  • error to start Windows Media Encoder

    - by George2
    Hello everyone, I am using the following code snippet to run on Windows Server 2003 x64 edition. I met with the following error when invoking encoder.start method. I am using Windows Media Encoder 9. System.Runtime.InteropServices.COMException 0xC00D1B67 My code snippet is below, does anyone have any ideas what is wrong? IWMEncSourceGroup SrcGrp; IWMEncSourceGroupCollection SrcGrpColl; SrcGrpColl = encoder.SourceGroupCollection; SrcGrp = (IWMEncSourceGroup)SrcGrpColl.Add("SG_1"); IWMEncVideoSource2 SrcVid; IWMEncSource SrcAud; SrcVid = (IWMEncVideoSource2)SrcGrp.AddSource(WMENC_SOURCE_TYPE.WMENC_VIDEO); SrcAud = SrcGrp.AddSource(WMENC_SOURCE_TYPE.WMENC_AUDIO); SrcVid.SetInput("ScreenCap://ScreenCapture1", "", ""); SrcAud.SetInput("Device://Default_Audio_Device", "", ""); // Specify a file object in which to save encoded content. IWMEncFile File = encoder.File; string CurrentFileName = Guid.NewGuid().ToString(); File.LocalFileName = CurrentFileName; CurrentFileName = File.LocalFileName; // Choose a profile from the collection. IWMEncProfileCollection ProColl = encoder.ProfileCollection; IWMEncProfile Pro; for (int i = 0; i < ProColl.Count; i++) { Pro = ProColl.Item(i); if (Pro.Name == "Screen Video/Audio High (CBR)") { SrcGrp.set_Profile(Pro); break; } } encoder.Start(); thanks in advance, George

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  • mtl, transformers, monads-fd, monadLib, and the paradox of choice

    - by yairchu
    Hackage has several packages for monad transformers: mtl: Monad transformer library transformers: Concrete functor and monad transformers monads-fd: Monad classes, using functional dependencies monads-tf: Monad classes, using type families monadLib: A collection of monad transformers. mtl-tf: Monad transformer library using type families mmtl: Modular Monad transformer library mtlx: Monad transformer library with type indexes, providing 'free' copies. compose-trans: Composable monad transformers (and maybe I missed some) Which one shall we use? mtl is the one in the Haskell Platform, but I keep hearing on reddit that it's uncool. But what's bad about choice anyway, isn't it just a good thing? Well, I saw how for example the authors of data-accessor had to make all these to cater to just the popular choices: data-accessor-monadLib library: Accessor functions for monadLib's monads data-accessor-monads-fd library: Use Accessor to access state in monads-fd State monad class data-accessor-monads-tf library: Use Accessor to access state in monads-tf State monad type family data-accessor-mtl library: Use Accessor to access state in mtl State monad class data-accessor-transformers library: Use Accessor to access state in transformers State monad I imagine that if this goes on and for example several competing Arrow packages evolve, we might see something like: spoonklink-arrows-transformers, spoonklink-arrows-monadLib, spoonklink-tfArrows-transformers, spoonklink-tfArrows-monadLib, ... And then I worry that if spoonklink gets forked, Hackage will run out of disk space. :) Questions: Why are there so many monad transformer packages? Why is mtl [considered] uncool? What are the key differences? Most of these seemingly competing packages were written by Andy Gill and are maintained by Ross Paterson. Does this mean that these packages are not competing but rather work together in some way? And do Andy and Ross consider any of their own packages as obsolete? Which one should me and you use?

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  • Need advice on OOP philosophy

    - by David Jenings
    I'm trying to get the wheels turning on a large project in C#. My previous experience is in Delphi, where by default every form was created at applicaton startup and form references where held in (gasp) global variables. So I'm trying to adapt my thinking to a 100% object oriented environment, and my head is spinning just a little. My app will have a large collection of classes Most of these classes will only really need one instance. So I was thinking: static classes. I'm not really sure why, but much of what I've read here says that if my class is going to hold a state, which I take to mean any property values at all, I should use a singleton structure instead. Okay. But there are people out there who for reasons that escape me, think that singletons are evil too. None of these classes is in danger of being used anywhere except in this program. So they could certainly work fine as regular objects (vs singletons or static classes) Then there's the issue of interaction between objects. I'm tempted to create a Global class full of public static properties referencing the single instances of many of these classes. I've also considered just making them properties (static or instance, not sure which) of the MainForm. Then I'd have each of my classes be aware of the MainForm as Owner. Then the various objects could refer to each other as Owner.Object1, Owner.Object2, etc. I fear I'm running out of electronic ink, or at least taxing the patience of anyone kind enough to have stuck with me this long. I hope I have clearly explained my state of utter confusion. I'm just looking for some advice on best practices in my situation. All input is welcome and appreciated. Thanks in advance, David Jennings

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  • Linq Query Performance , comparing Compiled query vs Non-Compiled.

    - by AG.
    Hello Guys, I was wondering if i extract the common where clause query into a common expression would it make my query much faster, if i have say something like 10 linq queries on a collection with exact same 1st part of the where clause. I have done a small example to explain a bit more . public class Person { public string First { get; set; } public string Last { get; set; } public int Age { get; set; } public String Born { get; set; } public string Living { get; set; } } public sealed class PersonDetails : List<Person> { } PersonDetails d = new PersonDetails(); d.Add(new Person() {Age = 29, Born = "Timbuk Tu", First = "Joe", Last = "Bloggs", Living = "London"}); d.Add(new Person() { Age = 29, Born = "Timbuk Tu", First = "Foo", Last = "Bar", Living = "NewYork" }); Expression<Func<Person, bool>> exp = (a) => a.Age == 29; Func<Person, bool> commonQuery = exp.Compile(); var lx = from y in d where commonQuery.Invoke(y) && y.Living == "London" select y; var bx = from y in d where y.Age == 29 && y.Living == "NewYork" select y; Console.WriteLine("All Details {0}, {1}, {2}, {3}, {4}", lx.Single().Age, lx.Single().First , lx.Single().Last, lx.Single().Living, lx.Single().Born ); Console.WriteLine("All Details {0}, {1}, {2}, {3}, {4}", bx.Single().Age, bx.Single().First, bx.Single().Last, bx.Single().Living, bx.Single().Born); So can some of the guru's here give me some advice if it would be a good practice to write query like var lx = "Linq Expression " or var bx = "Linq Expression" ? Any inputs would be highly appreciated. Thanks, AG

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  • HasMany relation inside a Join Mapping

    - by Sean McMillan
    So, I'm having a problem mapping in fluent nhibernate. I want to use a join mapping to flatten an intermediate table: Here's my structure: [Vehicle] VehicleId ... [DTVehicleValueRange] VehicleId DTVehicleValueRangeId AverageValue ... [DTValueRange] DTVehicleValueRangeId RangeMin RangeMax RangeValue Note that DTValueRange does not have a VehicleID. I want to flatten DTVehicleValueRange into my Vehicle class. Tgis works fine for AverageValue, since it's just a plain value, but I can't seem to get a ValueRange collection to map correctly. public VehicleMap() { Id(x => x.Id, "VehicleId"); Join("DTVehicleValueRange", x => { x.Optional(); x.KeyColumn("VehicleId"); x.Map(y => y.AverageValue).ReadOnly(); x.HasMany(y => y.ValueRanges).KeyColumn("DTVehicleValueRangeId"); // This Guy }); } The HasMany mapping doesn't seem to do anything if it's inside the Join. If it's outside the Join and I specify the table, it maps, but nhibernate tries to use the VehicleID, not the DTVehicleValueRangeId. What am I doing wrong?

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  • UCMA 3.0 How to build a list of recipients and then broadcast an IM call to those recipients

    - by ficuscr
    I am developing an application using UCMA 3.0 that will run as a service and send out periodic 'broadcasts' in the form of Instant Message calls. I have been using the book "Professional Unified Communications Development with Microsoft Lync Server 2010" and have everything provisioned fine and am able to establish an application endpoint. I am stuck on two aspects though. 1) How to get a list of all users of Lync? Everything the UCMA can do is centered on a single user. For example it allows me to retrieve all contacts/groups present on a given users 'contact list' but does not provide any means to query for a list of available contacts that could be added to one of those contact lists. On the MSDN forum I found this post which leads me to think my best bet is simply to query AD directly. 2) What is the best way to actually send a broadcast style IM? My working premise is to attempt something like what I've found in this code example (specifically the public void SendIM() method). So, get a list of recipients from AD, (looping on each on to check current presence?), and then use Automation to make the IM call for each recipient in the collection. Does that make sense? Do I need to check presence of the recipient or do I just optimistically make the IM calls irregardless of their current presence status? Can anyone point me to some working code demonstrating sending an IM broadcast? You would think this is probably one of the most common use cases however the SDK samples do not cover it. Thanks in advance.

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  • Using graphical ActiveX (COM) controls in WinForms project

    - by alex
    I have a collection (set) of ActiveX controls. I recieved them from our vendor company. I created a wrappers for them using tlbimp.exe and aximp.exe. All non-graphical controls work good. All graphical controls don't react on some methods. When I call their methods I get: TargetInvocativeException (InnerException is null). or Attempt to read/write protected memory. Our vendor company assure that their graphical activex controls work good. But they don't provide support service, so I have to find solution of my problem alone. And some more, All graphical activex controls don't react on mouseclick or any other mouse manipulations. But documentation says: it must change the color on mouse click. Maybe, someone have same symptoms and can help me ! I googled over that problem many pages but they don't help me. Maybe it's some Visual Studio settings or compiler options ? I use VS 2005.

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  • Poor Ruby on Rails performance when using nested :include

    - by Jeremiah Peschka
    I have three models that look something like this: class Bucket < ActiveRecord::Base has_many :entries end class Entry < ActiveRecord::Base belongs_to :submission belongs_to :bucket end class Submission < ActiveRecord::Base has_many :entries belongs_to :user end class User < ActiveRecord::Base has_many :submissions end When I retrieve a collection of entries doing something like: @entries = Entry.find(:all, :conditions => ['entries.bucket_id = ?', @bucket], :include => :submission) The performance is pretty quick although I get a large number of extra queries because the view uses the Submission.user object. However, if I add the user to the :include statement, the performance becomes terrible and it takes over a minute to return a total of 50 entries and submissions spread across 5 users. When I run the associated SQL commands, they complete in well under a second. @entries = Entry.find(:all, :conditions => ['entries.bucket_id = ?', @bucket], :include => {:submission => :user}) Why would this second command have such terrible performance compared to the first?

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