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  • Stretch ListBox Items hit area to full width if the ListBox?

    - by Nicholas
    I've looked around for an answer on this, but the potential duplicates are more concerned with presentation than interaction. I have a basic list box, and each item's content is a simple string. The ListBox itself is stretched to fill it's grid container, but each ListBoxItem's hitarea does not mirror the ListBox width. It looks as if the hitarea (pointer contact area) for each item is only the width of the text content. How do I make this stretch all the way across, regardless of the text size. I've set HorizontalContentAlignment to Stretch, but this doesn't solve my problem. My only other guess is that the content is actually stretching, but the background is invisible and so not capturing the mouse pointer. <ListBox Grid.Row="1" x:Name="ProjectsListBox" DisplayMemberPath="Name" ItemsSource="{Binding Path=Projects}" SelectedItem="{Binding Path=SelectedProject}" HorizontalContentAlignment="Stretch"/> The XAML is pretty straight forward on this. If I mouse over the text in one of the items, then the entire width of the item becomes active. I guess I just need to know how to create an interactive background that is invisible.

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  • Where are possible locations of queueing/buffering delays in Linux multicast?

    - by Matt
    We make heavy use of multicasting messaging across many Linux servers on a LAN. We are seeing a lot of delays. We basically send an enormous number of small packages. We are more concerned with latency than throughput. The machines are all modern, multi-core (at least four, generally eight, 16 if you count hyperthreading) machines, always with a load of 2.0 or less, usually with a load less than 1.0. The networking hardware is also under 50% capacity. The delays we see look like queueing delays: the packets will quickly start increasing in latency, until it looks like they jam up, then return back to normal. The messaging structure is basically this: in the "sending thread", pull messages from a queue, add a timestamp (using gettimeofday()), then call send(). The receiving program receives the message, timestamps the receive time, and pushes it in a queue. In a separate thread, the queue is processed, analyzing the difference between sending and receiving timestamps. (Note that our internal queues are not part of the problem, since the timestamps are added outside of our internal queuing.) We don't really know where to start looking for an answer to this problem. We're not familiar with Linux internals. Our suspicion is that the kernel is queuing or buffering the packets, either on the send side or the receive side (or both). But we don't know how to track this down and trace it. For what it's worth, we're using CentOS 4.x (RHEL kernel 2.6.9).

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  • Contacts & Autocomplete

    - by Vince
    First post. I'm new to android and programming in general. What I'm attempting to is to have an autocomplete text box pop up with auto complete names from the contact list. IE, if they type in "john" it will say "John Smith" or any john in their contacts. The code is basic, I pulled it from a few tutorials. private void autoCompleteBox() { ContentResolver cr = getContentResolver(); Uri contacts = Uri.parse("content://contacts/people"); Cursor managedCursor1 = cr.query(contacts, null, null, null, null); if (managedCursor1.moveToFirst()) { String contactname; String cphoneNumber; int nameColumn = managedCursor1.getColumnIndex("name"); int phoneColumn = managedCursor1.getColumnIndex("number"); Log.d("int Name", Integer.toString(nameColumn)); Log.d("int Number", Integer.toString(phoneColumn)); do { // Get the field values contactname = managedCursor1.getString(nameColumn); cphoneNumber = managedCursor1.getString(phoneColumn); if ((contactname != " " || contactname != null) && (cphoneNumber != " " || cphoneNumber != null)) { c_Name.add(contactname); c_Number.add(cphoneNumber); Toast.makeText(this, contactname, Toast.LENGTH_SHORT) .show(); } } while (managedCursor1.moveToNext()); } name_Val = (String[]) c_Name.toArray(new String[c_Name.size()]); phone_Val = (String[]) c_Number.toArray(new String[c_Name.size()]); ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_dropdown_item_1line, name_Val); personName.setAdapter(adapter); } personName is my autocompletetextbox. So it actually works when I use it in the emulator (4.2) with manually entered contacts through the people app, but when I use it on my device, it will not pop up with any names. I'm sure it's something ridiculous but I've tried to find the answer and I'm getting nowhere. Can't learn if I don't ask.

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  • How to catch unintentional function interpositioning with GCC?

    - by SiegeX
    Reading through my book Expert C Programming, I came across the chapter on function interpositioning and how it can lead to some serious hard to find bugs if done unintentionally. The example given in the book is the following: my_source.c mktemp() { ... } main() { mktemp(); getwd(); } libc mktemp(){ ... } getwd(){ ...; mktemp(); ... } According to the book, what happens in main() is that mktemp() (a standard C library function) is interposed by the implementation in my_source.c. Although having main() call my implementation of mktemp() is intended behavior, having getwd() (another C library function) also call my implementation of mktemp() is not. Apparently, this example was a real life bug that existed in SunOS 4.0.3's version of lpr. The book goes on to explain the fix was to add the keyword static to the definition of mktemp() in my_source.c; although changing the name altogether should have fixed this problem as well. This chapter leaves me with some unresolved questions that I hope you guys could answer: Should our software group adopt the practice of putting the keyword static in front of all functions that we don't want to be exposed? Does GCC have a way to warn about function interposition? We certainly don't ever intend on this happening and I'd like to know about it if it does. Can interposition happen with functions introduced by static libraries? Thanks for the help.

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  • iPhone: How to use CGContextConcatCTM for saving a transformed image properly?

    - by Irene
    I am making an iPhone application that loads an image from the camera, and then the user can select a second image from the library, move/scale/rotate that second image, and then save the result. I use two UIImageViews in IB as placeholders, and then apply transformations while touching/pinching. The problem comes when I have to save both images together. I use a rect of the size of the first image and pass it to UIGraphicsBeginImageContext. Then I tried to use CGContextConcatCTM but I can't understand how it works: CGRect rect = CGRectMake(0, 0, img1.size.width, img1.size.height); // img1 from camera UIGraphicsBeginImageContext(rect.size); // Start drawing CGContextRef ctx = UIGraphicsGetCurrentContext(); CGContextClearRect(ctx, rect); // Clear whole thing [img1 drawAtPoint:CGPointZero]; // Draw background image at 0,0 CGContextConcatCTM(ctx, img2.transform); // Apply the transformations of the 2nd image But what do I need to do next? What information is being held in the img2.transform matrix? The documentation for CGContextConcatCTM doesn't help me that much unfortunately.. Right now I'm trying to solve it by calculating the points and the angle using trigonometry (with the help of this answer), but since the transformation is there, there has to be an easier and more elgant way to do this, right?

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  • Jquery find first visible element after horizontal scroll

    - by lolo flores
    I’m new (only two weeks old) in Jquery, so please bear with me. I know that a very similar question was asked some time ago but I do not know how to adapt the answer to my problem. I have a very wide multicolumn layout something like this: | aaaa | bbbb | cccc | … | | aaaa | b | cc | … | | aaa | cccc | ddd | … | The code looks like: <div id="container"> <p>aaaaaaaaaaa</p> <p>bbbbb</p> <p>ccccccccccc</p> <p>dddddddddd</p> ... <p>xxxxxx</p> </div> There is no vertical scrolling and the container width is set in such a way that only two columns are shown. The user scrolls left or right to see the relevant text. What I want is to get the position currently on display, store it (maybe in a cookie) and retrieve it the next time the user opens the page. I think that I need a way of finding out what paragraph is currently the left-top most, but other suggestions are very welcome. Any ideas? btw: this is an internal project, so Mozilla only :-) Thanks Lolo

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  • How do I refer to a windows form control by name (C# / VB)

    - by Alex
    Suppose I have a label control on a windows form called "UserName". How can I refer to that label programmatically using the label name? For example I can do: For each ctrl as Control in TabPage.Controls If ctrl.Name = "UserName" Then ' Do something End If Next This seems quite inefficient. I would like to do something like: TabPage.Controls("UserName").Text = "Something" I did some googling but couldn't find a satisfactory answer. Most suggested looping, some said .NET 2005 doesn't support direct refenece using string name, and FindControl method was asp.net only... EDIT Thanks for the response so far. Here is a bit more detail. I have a windows form with three tabpages, all of which a very similar in design and function i.e. same drop down menus, labels, react in simlar way to events etc. Rather than write code for each event per tabpage I have built a class that controls the events etc. per tabpage. For example, on each tabpage there is a Label called "RecordCounter" that simply shows the number of rows in the datagridview when it is populated by selection of a variable in a drop down menu. So what I want to be able to do is, upon selection of a variable in the drop down menu, the datagridview populates itself with data, and then I simply want to display the number of rows in a label ("RecordCounter"). This is exactly the same process on each tabpage so what I am doing is passing the tabpage to the class and then I want to be able to refer to the "RecordCounter" and then update it. In my class I set the ActivePage property to be the TabPage that the user has selected and then want to be able to do something like: ActivePage.RecordCounter.Text = GetNumberOfRows()

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  • $_SESSION v. $_COOKIE

    - by taeja87
    I learned about $_SESSION about several weeks ago when creating a login page. I can successfully login and use it with variables. Currently I am trying to understand $_SESSION and $_COOKIE. Please correct me if I am wrong, I can use $_SESSION when logging in and moving around pages. With $_COOKIE, it is used to remember when I last visit and preferences. Another thing involving cookies is that when websites use advertisements (for example: Google AdSense), they use the cookies to track when visitor click on a advertisement, right? I can use both ($_SESSION & $_COOKIE)? I read somewhere that you can store the session_id as value for the cookie. Also, I read about security which let to me finding this: What do I need to store in the php session when user logged in?. Is using session_regenerate_id good for when a user comes back to the site? And this: How to store a cookie with php involving uniqid. For those wanting to know about the login, I use email and password. That way the user can be able to change their username. I look forward to learning more about these two from anybody who would like to share their knowledge about it. If I asked too many question, you can just answer the one that you have more experience with. If you need more information, just ask since I might have forgotten to include something. Thank You. Found this: What risks should I be aware of before allowing advertisements being placed on my website?

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  • How best to implement support for multiple devices in a web application.

    - by Kabeer
    Hello. My client would like a business application to support 'every possible device'. The application in question is essentially a web application and 'every possible device', I believe encompasses mobile phones, netbooks, ipad, other browser supporting devices, etc. The application is somewhat complex w.r.t. the data it captures and other functions it performs (reporting). If I continue to honor increasing complexity in the application, I guess there are more chances of it not working on other devices. I'd like to know how web applications support multiple devices conventionally? Are there multiple versions of presentation layer (like many times I find m.website.com dedicated for mobile devices)? Further, if my application is to take advantage of Java Script, RIA (Flash, SilverLight) then what are the consequences and workarounds? Mine is a .Net based application and the stack also contains Ext JS Java Script library. While I would like to use it for sure, considering that I would be doing a lot of work in Java Script rather than HTML, this could be a problem. The answer to the above could be descriptive. If there is something already prescribed out there, please share the link(s). Thanks.

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  • Dynamic Select boxes page load

    - by Chris
    Hello, I have a dynamic chained select box that I am attempting to show the value of on a page load. In my chained select box, it will default to the first option within the select box on page load, could anyone provide assitance? I stumbled upon this thread, but I can't seem to translate what they are doing with that answer to my language of CF. Dynamic chained drop downs on page refresh Here is the JS script I am using. function dynamicSelect(id1, id2) { // Feature test to see if there is enough W3C DOM support if (document.getElementById && document.getElementsByTagName) { // Obtain references to both select boxes var sel1 = document.getElementById(id1); var sel2 = document.getElementById(id2); // Clone the dynamic select box var clone = sel2.cloneNode(true); // Obtain references to all cloned options var clonedOptions = clone.getElementsByTagName("option"); // Onload init: call a generic function to display the related options in the dynamic select box refreshDynamicSelectOptions(sel1, sel2, clonedOptions); // Onchange of the main select box: call a generic function to display the related options in the dynamic select box sel1.onchange = function() { refreshDynamicSelectOptions(sel1, sel2, clonedOptions); } } } function refreshDynamicSelectOptions(sel1, sel2, clonedOptions) { // Delete all options of the dynamic select box while (sel2.options.length) { sel2.remove(0); } // Create regular expression objects for "select" and the value of the selected option of the main select box as class names var pattern1 = /( |^)(select)( |$)/; var pattern2 = new RegExp("( |^)(" + sel1.options[sel1.selectedIndex].value + ")( |$)"); // Iterate through all cloned options for (var i = 0; i < clonedOptions.length; i++) { // If the classname of a cloned option either equals "select" or equals the value of the selected option of the main select box if (clonedOptions[i].className.match(pattern1) || clonedOptions[i].className.match(pattern2)) { // Clone the option from the hidden option pool and append it to the dynamic select box sel2.appendChild(clonedOptions[i].cloneNode(true)); } } } Thanks so much for any assistance

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  • cellForRowAtIndexPath not called for all sections

    - by Wynn
    I have a UITableView that has five sections. Just as the title describes cellForRowAtIndexPath is only being called for the first four. All connections have been made concerning the datasource and delegate. Also, my numberOfSectionsInTableView clearly returns 5. Printing out the number of sections from within cellForRowAtIndexPath shows the correct number, thus confirming that cellForRowAtIndexPath is simply not being called for all sections. What on earth is going on? I looked pretty hard for an answer to this question but could't find one. If this has already been answered please forgive me and point me in the correct direction. My cellForRowAtIndexPath: - (UITableViewCell *)tableView:(UITableView *)theTableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [theTableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier]; } switch (indexPath.section) { case 0: cell.textLabel.text = ticket.description; break; case 1: cell.textLabel.text = ticket.ticketStatus; break; case 2: cell.textLabel.text = ticket.priority; break; case 3: cell.textLabel.text = ticket.customerOfficePhone; break; case 4: { //This never ever gets executed Comment *comment = [ticket.comments objectAtIndex:indexPath.row]; cell.textLabel.text = comment.commentContent; break; } } return cell; } My numberOfSectionsInTableView: - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return 5; } My numberOfRowsInSection: - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { NSInteger numberOfRows; if (section == 4) { numberOfRows = [ticket.comments count]; } else { numberOfRows = 1; } return numberOfRows; } Any suggestions are appreciated. Thanks in advance.

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  • Creating a process in ASP.NET MVC controller

    - by GRKamath
    I have a requirement to run an application through my MVC controller. To get the installation path I used following link (I used answer provided by Fredrik Mörk). It worked and I could able to run the exe through a process. The problem occurred when I deployed this solution on IIS where it did not create the process as it was creating in local dev environment. Can anybody tell me how to create a windows process through a solution which is hosted on IIS ? private string GetPathForExe(string fileName) { private const string keyBase = @"SOFTWARE\Wow6432Node\MyApplication"; RegistryKey localMachine = Registry.LocalMachine; RegistryKey fileKey = localMachine.OpenSubKey(string.Format(@"{0}\{1}", keyBase, fileName)); object result = null; if (fileKey != null) { result = fileKey.GetValue("InstallPath"); } fileKey.Close(); return (string)result; } public void StartMyApplication() { Process[] pname = Process.GetProcessesByName("MyApplication"); if (pname.Length == 0) { string appDirectory = GetPathForExe("MyApplication"); Directory.SetCurrentDirectory(appDirectory); ProcessStartInfo procStartInfo = new ProcessStartInfo("MyApplication.exe"); procStartInfo.WindowStyle = ProcessWindowStyle.Hidden; Process proc = new Process(); proc.StartInfo = procStartInfo; proc.Start(); } }

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  • Oddities in Linq-to-SQL generated code related to property change/changing events

    - by Lasse V. Karlsen
    I'm working on creating my own Linq-to-Sql generated classes in order to learn the concepts behind it all. I have some questions, if anyone knows the answer to one or more of these I'd be much obliged. The code below, and thus the questions, are from looking at code generated by creating a .DBML file in the Visual Studio 2010 designer, and inspecting the .Designer.cs file afterwards. 1. Why is INotifyPropertyChanging not passing the property name The event raising method is defined like this: protected virtual void SendPropertyChanging() Why isn't the name of the property that is changing passed to the event here? It is defined to be part of the EventArgs descendant that is passed to the event handler, but the method only passes an empty such value to it. 2. Why are the EntitySet<X> attach/detach methods not raising property changed? For an EntitySet<X> reference, the following two methods are generated: private void attach_EmailAddress1s(EmailAddress1 entity) { this.SendPropertyChanging(); entity.Person1 = this; } private void detach_EmailAddress1s(EmailAddress1 entity) { this.SendPropertyChanging(); entity.Person1 = null; } Why isn't SendPropertyChanged also called here? I'm sure I have more questions later, but for now these will suffice :)

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  • Beginner Ques::How to delete records permanently in case of linked tables?

    - by Serenity
    Let's say I have these 2 tables QuesType and Ques:- QuesType QuestypeID|QuesType |Active ------------------------------------ 101 |QuesType1 |True 102 |QuesType2 |True 103 |XXInActiveXX |False Ques QuesID|Ques|Answer|QUesTypeID|Active ------------------------------------ 1 |Ques1|Ans1 |101 |True 2 |Ques2|Ans2 |102 |True 3 |Ques3|Ans3 |101 |True In the QuesType Table:- QuesTypeID is a Primary key In the Ques Table:- QuesID is a Primary key and QuesType ID is the Foreign Key that refernces QuesTypeID from QuesType Table Now I am unable to delete records from QuesType Table, I can only make QuesType inactive by setting Active=False. I am unable to delete QuesTypes permanently because of the Foreign key relation it has with Ques Table. So , I just set the column Active=false and those Questypes then don't show on my grid wen its binded. What I want to do is be able to delete any QuesType permamnently. Now it can only be deleted if its not being used anywhere in the Ques table, right? So to delete any QuesType permanently I thot this is what I could do:- In the grid that displays QuesTypes, I have this check box for Active and a button for delete.What I thot was, when a user makes some QuesType inactive then OnCheckChanged() event will run and that will have the code to delete all the Questions in Ques table that are using that QuesTypeID. Then on the QuesType grid, that QuesType would show as Deactivated and only then can a user delete it permanently. Am I thinking correctly? Currently in my DeleteQuesType Stored Procedure what I am doing is:- Setting the Active=false and Setting QuesTye= some string like XXInactiveXX Is there any other way?

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  • When using Direct3D, how much math is being done on the CPU?

    - by zirgen
    Context: I'm just starting out. I'm not even touching the Direct3D 11 API, and instead looking at understanding the pipeline, etc. From looking at documentation and information floating around the web, it seems like some calculations are being handled by the application. That, is, instead of simply presenting matrices to multiply to the GPU, the calculations are being done by a math library that operates on the CPU. I don't have any particular resources to point to, although I guess I can point to the XNA Math Library or the samples shipped in the February DX SDK. When you see code like mViewProj = mView * mProj;, that projection is being calculated on the CPU. Or am I wrong? If you were writing a program, where you can have 10 cubes on the screen, where you can move or rotate cubes, as well as viewpoint, what calculations would you do on the CPU? I think I would store the geometry for the a single cube, and then transform matrices representing the actual instances. And then it seems I would use the XNA math library, or another of my choosing, to transform each cube in model space. Then get the coordinates in world space. Then push the information to the GPU. That's quite a bit of calculation on the CPU. Am I wrong? Am I reaching conclusions based on too little information and understanding? What terms should I Google for, if the answer is STFW? Or if I am right, why aren't these calculations being pushed to the GPU as well?

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  • OnClickListener onClick=true and selector

    - by azerto00
    I have not found any answer for my problem, so I need your help ... I have an LinearLayout which I want to be clickable in order to lunch another activity. So I implement an onClickListener to it. I created an selector for this LinearLayout in order that what someone click on it, the background change. I just don't understand that : If my LinearLayout doesn't have android:clickable="true" in the xml, I'm able to click on it and get what I want but the selector doesn't work. If I remove this line, it is the opposite .. the selector work but not the onClick event. So, can anyone can explain me why ? Just in case, here is my the content of my selector file : <selector xmlns:android="http://schemas.android.com/apk/res/android"> <item android:drawable="@drawable/btn_restaurants_background_state_pressed" android:state_pressed="true"></item> <item android:drawable="@drawable/btn_restaurants_background_state_pressed" android:state_focused="true"></item> <item android:drawable="@drawable/btn_restaurants_background_state_pressed" android:state_selected="true"></item> <item android:drawable="@drawable/btn_restaurants_background_state_normal"></item> </selector> Thanks you in advance

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  • How to convert "0" and "1" to false and true

    - by Chris
    I have a method which is connecting to a database via Odbc. The stored procedure which I'm calling has a return value which from the database side is a 'Char'. Right now I'm grabbing that return value as a string and using it in a simple if statement. I really don't like the idea of comparing a string like this when only two values can come back from the database, 0 and 1. OdbcCommand fetchCommand = new OdbcCommand(storedProc, conn); fetchCommand.CommandType = CommandType.StoredProcedure; fetchCommand.Parameters.AddWithValue("@column ", myCustomParameter); fetchCommand.Parameters.Add("@myReturnValue", OdbcType.Char, 1). Direction = ParameterDirection.Output; fetchCommand.ExecuteNonQuery(); string returnValue = fetchCommand.Parameters["@myReturnValue"].Value.ToString(); if (returnValue == "1") { return true; } What would be the proper way to handle this situation. I've tried 'Convert.ToBoolean()' which seemed like the obvious answer but I ran into the 'String was not recognized as a valid Boolean. ' exception being thrown. Am I missing something here, or is there another way to make '1' and '0' act like true and false? Thanks!

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  • How would I compare two Lists(Of <CustomClass>) in VB?

    - by Kumba
    I'm working on implementing the equality operator = for a custom class of mine. The class has one property, Value, which is itself a List(Of OtherClass), where OtherClass is yet another custom class in my project. I've already implemented the IComparer, IComparable, IEqualityComparer, and IEquatable interfaces, the operators =, <>, bool and not, and overriden Equals and GetHashCode for OtherClass. This should give me all the tools I need to compare these objects, and various tests comparing two singular instances of these objects so far checks out. However, I'm not sure how to approach this when they are in a List. I don't care about the list order. Given: Dim x As New List(Of OtherClass) From {New OtherClass("foo"), New OtherClass("bar"), New OtherClass("baz")} Dim y As New List(Of OtherClass) From {New OtherClass("baz"), New OtherClass("foo"), New OtherClass("bar")} Then (x = y).ToString should print out True. I need to compare the same (not distinct) set of objects in this list. The list shouldn't support dupes of OtherClass, but I'll have to figure out how to add that in later as an exception. Not interested in using LINQ. It looks nice, but in the few examples I've played with, adds a performance overhead in that bugs me. Loops are ugly, but they are fast :) A straight code answer is fine, but I'd like to understand the logic needed for such a comparison as well. I'm probably going to have to implement said logic more than a few times down the road.

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  • Is it getting to be time for C# to support compile-time macros?

    - by Robert Rossney
    Thus far, Microsoft's C# team has resisted adding formal compile-time macro capabilities to the language. There are aspects of programming with WPF that seem (to me, at least) to be creating some compelling use cases for macros. Dependency properties, for instance. It would be so nice to just be able to do something like this: [DependencyProperty] public string Foo { get; set; } and have the body of the Foo property and the static FooProperty property be generated automatically at compile time. Or, for another example an attribute like this: [NotifyPropertyChanged] public string Foo { get; set; } that would make the currently-nonexistent preprocessor produce this: private string _Foo; public string Foo { get { return _Foo; } set { _Foo = value; OnPropertyChanged("Foo"); } } You can implement change notification with PostSharp, and really, maybe PostSharp is a better answer to the question. I really don't know. Assuming that you've thought about this more than I have, which if you've thought about it at all you probably have, what do you think? (This is clearly a community wiki question and I've marked it accordingly.)

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  • SELECT SQL Variable - should i avoid using this syntax and always use SET?

    - by Sholom
    Hi All, This may look like a duplicate to here, but it's not. I am trying to get a best practice, not a technical answer (which i already (think) i know). New to SQL Server and trying to form good habits. I found a great explanation of the functional differences between SET @var = and SELECT @var = here: http://vyaskn.tripod.com/differences_between_set_and_select.htm To summarize what each has that the other hasn't (see source for examples): SET: ANSI and portable, recommended by Microsoft. SET @var = (SELECT column_name FROM table_name) fails when the select returns more then one value, eliminating the possibility of unpredictable results. SET @var = (SELECT column_name FROM table_name) will set @var to NULL if that's what SELECT column_name FROM table_name returned, thus never leaving @var at it's prior value. SELECT: Multiple variables can be set in one statement Can return multiple system variables set by the prior DML statement SELECT @var = column_name FROM table_name would set @var to (according to my testing) the last value returned by the select. This could be a feature or a bug. Behavior can be changed with SELECT @j = (SELECT column_name FROM table_name) syntax. Speed. Setting multiple variables with a single SELECT statement as opposed to multiple SET/SELECT statements is much quicker. He has a sample test to prove his point. If you could design a test to prove the otherwise, bring it on! So, what do i do? (Almost) always use SET @var =, using SELECT @var = is messy coding and not standard. OR Use SELECT @var = freely, it could accomplish more for me, unless the code is likely to be ported to another environment. Thanks

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  • Attempt to use a while loop for the 'next' arg of a for loop generates #arg error

    - by JerryK
    Am attempting to teach myself to program using Tcl. The task i've set myself to motivate my learning of Tcl is to solve the 8 queens problem. My approach to creating a program is to successively 'prototype' a solution. I have asked an earlier question related to the correctly laying out the nested for loops and received a helpful answer. To my dismay I find that the next development of my code creates the same interpreter error : "wrong # args" I have been careful to have an open brace at the end of the line preceding the while loop command. I've also tried to put the arguments of the whileloop in braces. This generates a different error. I have sincerely tried to understand the Tcl syntax man page - not too successfully - suggested by the answerer of my earlier question. Here is the code set allowd 1 set notallowd 0 for {set r1p 1} {$r1p <= 8} {incr r1p } { puts "1st row q placed at $r1p" ;# re-initialize r2 'free for q placemnt' array after every change of r1 q pos: for {set i 1 } {$i <= 8} {incr i} { set r2($i) $allowd } for { set r2($r1p) $notallowd ; set r2([expr $r1p-1]) $notallowd ; set r2([expr $r1p+1]) $notallowd ; set r2p 1} {$r2p <= 8} { ;# 'next' arg of r2 forloop will be a whileloop : while r2($r2p)== $notallowd incr r2p } { puts "2nd row q placed at $r2p" ;# end of 'commnd' arg of r2 forloop } } Where am I going wrong? EDIT : to provide clear reply @slebetman As stated in my text, I did brace the arguments of the whileloop (indeed that was how i first wrote the code) below is exactly the layout of the r2 forloop tried: for { set r2($r1p) $notallowd ; set r2([expr $r1p-1]) $notallowd ; set r2([expr $r1p+1]) $notallowd ; set r2p 1} {$r2p <= 8} { ;# 'next' arg of r2 forloop will be a whileloop : while { r2($r2p)== $notallowd } { incr r2p } } { puts "2nd row q placed at $r2p" ;# end of 'commnd' arg of r2 forloop } but this generates the fatal interpreter error : "unknown math function 'r2' while compiling while { r2($r2p .... "

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  • Has anyone ever had OpenCV work with Python 2.7 on MacOS 10.6?

    - by ?????
    I've been trying on and off for the past 6 months to get OpenCV to work with Python on MacOS. Every time there's a new release, I try again and fail. I've tried both 64-bit and 32-bit, and both the xcode gcc and gcc installed via macports. I just spend the past two days on it, hopeful that the latest OpenCV release, that appears to include Python support directly would work. It doesn't. I've also tried and failed to use this: http://code.google.com/p/pyopencv/ I've been using OpenCV with C++ or Microsoft C++/CLI for the past few years, but I'd love to use it with Python on a Mac because that is my primary development environment. I'd love to hear from anyone who's actually been able to get the opencv python examples to run under Mac OS 10.6, either 32 or 64-bit. My last attempt was to follow the instructions on this page http://recursive-design.com/blog/2010/12/14/face-detection-with-osx-and-python/ with a clean, fresh install of 10.6 on a 64-bit capable Mac. My PYTHONPATH is set, and I can see the cv library in it. But an "import cv" from python fails. Previously, the closest I've ever gotten (again, staring on a clean, fresh 10.6 install) was this: Python 2.7.1 (r271:86882M, Nov 30 2010, 10:35:34) [GCC 4.2.1 (Apple Inc. build 5664)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> import cv Fatal Python error: Interpreter not initialized (version mismatch?) Abort trap thrilllap-2:~ swirsky$ I've seen a lot of folks answering similar questions here, but have never seen an definitive answer for it.

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  • How do I compare two PropertyInfos or methods reliably?

    - by Rob Ashton
    Same for methods too: I am given two instances of PropertyInfo or methods which have been extracted from the class they sit on via GetProperty or GetMember etc, (or from a MemberExpression maybe). I want to determine if they are in fact referring to the same Property or the same Method so (propertyOne == propertyTwo) or (methodOne == methodTwo) Clearly that isn't going to actually work, you might be looking at the same property, but it might have been extracted from different levels of the class hierarchy (in which case generally, propertyOne != propertyTwo) Of course, I could look at DeclaringType, and re-request the property, but this starts getting a bit confusing when you start thinking about Properties/Methods declared on interfaces and implemented on classes Properties/Methods declared on a base class (virtually) and overridden on derived classes Properties/Methods declared on a base class, overridden with 'new' (in IL world this is nothing special iirc) At the end of the day, I just want to be able to do an intelligent equality check between two properties or two methods, I'm 80% sure that the above bullet points don't cover all of the edge cases, and while I could just sit down, write a bunch of tests and start playing about, I'm well aware that my low level knowledge of how these concepts are actually implemented is not excellent, and I'm hoping this is an already answered topic and I just suck at searching. The best answer would give me a couple of methods that achieve the above, explaining what edge cases have been taken care of and why :-)

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  • Computing, storing, and retrieving values to and from an N-Dimensional matrix

    - by Adam S
    This question is probably quite different from what you are used to reading here - I hope it can provide a fun challenge. Essentially I have an algorithm that uses 5(or more) variables to compute a single value, called outcome. Now I have to implement this algorithm on an embedded device which has no memory limitations, but has very harsh processing constraints. Because of this, I would like to run a calculation engine which computes outcome for, say, 20 different values of each variable and stores this information in a file. You may think of this as a 5(or more)-dimensional matrix or 5(or more)-dimensional array, each dimension being 20 entries long. In any modern language, filling this array is as simple as having 5(or more) nested for loops. The tricky part is that I need to dump these values into a file that can then be placed onto the embedded device so that the device can use it as a lookup table. The questions now, are: What format(s) might be acceptable for storing the data? What programs (MATLAB, C#, etc) might be best suited to compute the data? C# must be used to import the data on the device - is this possible given your answer to #1?

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  • Cross Thread problem C#

    - by Frederik Witte
    Hello people - I got this code (lg_log is a listbox, and i want it to log the start_server.bat) Here is the code i got: public void bt_play_Click(object sender, EventArgs e) { lg_log.Items.Add("Starting Mineme server .."); string directory = Directory.GetCurrentDirectory(); var info = new ProcessStartInfo(directory + @"\start_base.bat") {UseShellExecute = false, RedirectStandardOutput = true, CreateNoWindow = true, WorkingDirectory = directory + @"\Servers\Base"}; var proc = new Process { StartInfo = info, EnableRaisingEvents = true }; proc.OutputDataReceived += (obj, args) => { if (args.Data != null) { lg_log.Items.Add(args.Data); } }; proc.Start(); proc.BeginOutputReadLine(); lg_log.Items.Add("Server is now running!"); proc.WaitForExit(); } When i run this, i'll get an error .. Anybody can help me? I'll rate the answer up! :D Edit: The error i get is this: System.InvalidOperationException Hope it helps :) The error comes at the lg_log.Items.Add(args.Data); code line

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