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  • Help me understand Dispose() implementation code from MSDN

    - by Benny
    the following code is from MSDN: Idisposable pattern protected virtual void Dispose(bool disposing) { // If you need thread safety, use a lock around these // operations, as well as in your methods that use the resource. if (!_disposed) { if (disposing) { if (_resource != null) _resource.Dispose(); Console.WriteLine("Object disposed."); } // Indicate that the instance has been disposed. _resource = null; _disposed = true; } } why the following statement: _resource = null; _disposed = true; are not enclosed by if (disposing) statement block? for me i would probably write like this: if (disposing) { if (_resource != null) { _resource.Dispose(); _resource = null; _disposed = true; } Console.WriteLine("Object disposed."); } anything wrong with my version?

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  • How can I create a generic constructor? (ie. BaseClass.FromXml(<param>)

    - by SofaKng
    I'm not sure how to describe this but I'm trying to create a base class that contains a shared (factory) function called FromXml. I want this function to instantiate an object of the proper type and then fill it via an XmlDocument. For example, let's say I have something like this: Public Class XmlObject Public Shared Function FromXml(ByVal source as XmlDocument) As XmlObject // <need code to create SPECIFIC TYPE of object and return it End Function End Class Public Class CustomObject Inherits XmlObject End Class I'd like to be able to do something like this: Dim myObject As CustomObject = CustomObject.FromXml(source) Is this possible?

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  • error string list handle in C#

    - by Chelsea_cole
    Same namespace: 2 forms. public class Account //frm1 { public string Username; public string Password; } public class ListAcc { public static List<Account> UserList; } private void button1_Click(object sender, EventArgs e) { List<Account> UserList = new List<Account>(); Account acc = new Account(); acc.Username = textBox1.Text; acc.Password = textBox2.Text; UserList.Add(acc); } private void button2_Click(object sender, EventArgs e) //frm2 { string p = frmDangky.ListAcc.UserList[0].Username; // null ->error string p = frmDangky.ListAcc.UserList[0].Password; // null ->error } Someone help me? :( why my string is NULL???????? The textBox is not empty... Thanks!

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  • Using C# to iterate form fields with same name

    - by itsatrp
    I have a section of a form that I need to handle differently from the rest of form results. In the section that needs special handling I need to iterate over 3 form fields that have the same name. They have to have the same name, I can't change it. The section of the form I am referring to looks something like this: <td><input name="Color" size="20" value="" type="text"></td> Using C# I try something like this: I try to handle it like this: int i; for (i = 1; i <= Request.Form["Color"][i]; i++) { colorName.Text += Request.Form["Color"]; } Which leads to the following exception: System.NullReferenceException: Object reference not set to an instance of an object. How should I be handling form fields with the same name?

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  • Qt C++ XML, validating against a DTD?

    - by Airjoe
    Is there a way to validate an XML file against a DTD with Qt's XML handling? I've tried googling around but can't seem to get a straight answer. If Qt doesn't include support for validating an XML file, what might be the process of implementing validation myself? Any good reference to start with in regards to validating XML against a spec? Thanks for the help!

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  • Is it guaranteed that False == 0 and True == 1 in Python?

    - by EOL
    Is it guaranteed that False == 0 and True == 1, in Python? For instance, is it in any way guaranteed that the following code will always produce the same results, whatever the version of Python (existing and in the foreseeable future)? 0 == False # True 1 == True # True ['zero', 'one'][False] # is 'zero' Any reference to the official documentation would be much appreciated! Other comments would be appreciated too… :)

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  • post data through httpWebRequest

    - by user304901
    Hello, everybody. I need to "Post" some data to an external website using HttpWebRequest object from my application(desktop) and get a response back into my application through HttpWebResponse object. But the webpage on which i m posting data have textboxes which have dynamic names. how can i get the name of those textboxes and post data in httpwebresquest. for example when i load the page the textbox name is like this "U2FsdGVkX183MTQyNzE0MrhLOmUpqd3eL60xF19RmCwLlSiG5nC1H6wvtBDhjI3uM1krX_B8Fwc" but when i refresh the page name change to this "U2FsdGVkX182MjMwNjIzMPAtotst_q9PP9TETomXB453Mq3M3ZY5HQt70ZeyxbRb118Y8GQbgP8" Thanks for any suggestions.

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  • Finding the heaviest of N objects using M scales

    - by cpprulez
    We have N objects and M scales. It's up to us what the objects are, and we need to position the objects on the scales so that it is undoubtful which is the heaviest object. For example, if we have 3 objects: "a", "b", "c" and 2 scales, one possible solution is "a" "b", "b" = "c" (here "a" is the heaviest). I need an algorithm which generates such solutions given N and M. Also let's assume that "a" is always the heaviest object. I've lost a few hours figuring out how to do it, but no matter what I figure out, there's always cases which I miss. For example, another solution is: "a" + "c" = 2 * "b", "a" "c".

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  • Best online resource to learn Python?

    - by Sreenath
    I am new to any scripting language. But, Still I worked on scripting a bit like tailoring other scripts to work for my purpose. For me, What is the best online resource to learn Python? Some Online Resources: http://docs.python.org/tut/tut.html - Beginners http://diveintopython.org/ - Intermediate http://www.pythonchallenge.com/ - Expert Skills http://docs.python.org/ - collection of all knowledge Some more: A Byte of Python. Python 2.5 Quick Reference Python Side bar A Nice blog for beginners Think Python: An Introduction to Software Design

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  • Why can't you call a non-static method from a static method?

    - by VoodooChild
    I have a static method [Method1] in my class, which calls another method [Method2] in the same class and is not a static method. But this is a no-no. I get this error: An object reference is required for the non-static field, method, or property "ClassName.MethodName()" Can someone please briefly describe why? including other things that might be related to this.

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  • fast on-demand c++ compilation [closed]

    - by Amit Prakash
    I'm looking at the possibility of building a system where when a query hits the server, we turn the query into c++ code, compile it as shared object and the run the code. The time for compilation itself needs to be small for it to be worthwhile. My code can generate the corresponding c++ code but if I have to write it out on disk and then invoke gcc to get a .so file and then run it, it does not seem to be worth it. Are there ways in which I can get a small snippet of code to compile and be ready as a share object fast (can have a significant start up time before the queries arrive). If such a tool has a permissive license thats a further plus. Edit: I have a very restrictive query language that the users can use so the security threat is not relevant. My own code translates the query into c++ code. The answer mentioning clang is perfect.

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  • How to get number of delete using NHibernate IStatistics

    - by epitka
    I am trying to get the number of delete statements issued during the session, so I enabled statistics generation and I got a reference to it through SessionFactory.Statistics. But I don't see a way to get the global number of deletes. I can get the statistics for the entity, but I have one many-to-many mapped relationship that does not materialize in an entity, everything is done through a table that is not mapped to an entity. Is there a way to get this number?

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  • cygwin sed substitution against commands in history

    - by Ira
    I couldn't find an answer for this exact problem, so I'll ask it. I'm working in Cygwin and want to reference previous commands using !n notation, e.g., if command 5 was which ls, then !5 runs the same command. The problem is when trying to do substitution, so running: !5:s/which \([a-z]\)/\1/ should just run ls, or whatever the argument was for which for command number 5. I've tried several ways of doing this kind of substitution and get the same error: bash: :s/which \([a-z]*\)/\1/: substitution failed

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  • How to make Event visible?

    - by eflles
    Inside a Silverlight library project I have a public event, which is not visible for other classes. How can I make the event visible? When I try the following code, I can not locate the event in the "ReceivingClass". .dll - file: Public Class MyClass Public Event MyEvent(ByVal sender As Object, ByVal e As EventArgs) Public Sub OnStart() RaiseEvent MyEvent(Me, new EventArgs) End Sub End Class Silverlight app: Imports MyClass Public Class ReceivingClass Public Sub New() Dim myClass As new MyClass AddHandler myClass.MyEvent, AddressOf Me.EventHandler End Sub Private Sub EventHandler(ByVal sender As Object, ByVal e As EventArgs) 'Handle Event End Sub End Class

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  • How to detect tab key pressing in C#?

    - by user342325
    I want to detect when tab key is pressed in a textBox and focus the next textbox in the panel. I have tried out keyPressed method and keyDown method. But when I run the program and debug those methods are not calling when the tab key is pressed. Here is my code. private void textBoxName_KeyDown(object sender, KeyEventArgs e) { if (e.KeyCode == Keys.Tab) { textBoxUsername.Focus(); } } private void textBoxName_KeyPress(object sender, KeyPressEventArgs e) { if (e.KeyChar==(char)Keys.Tab) { textBoxUsername.Focus(); } } Please correct me.Thank you.

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  • i got an error in login code

    - by user298349
    I tried writing a login code in vc#..i got the following error..'The type or namespace name 'LoginControl' does not exist in the namespace 'ErikSchmidt' (are you missing an assembly reference?)' Pls help me rectify this error.

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  • Using Assert to compare two objects

    - by baron
    Hi everyone, Writing test cases for my project, one test I need is to test deletion. This may not exactly be the right way to go about it, but I've stumbled upon something which isn't making sense to me. Code is like this: [Test] private void DeleteFruit() { BuildTestData(); var f1 = new Fruit("Banana",1,1.5); var f2 = new Fruit("Apple",1,1.5); fm.DeleteFruit(f1,listOfFruit); Assert.That(listOfFruit[1] == f2); } Now the fruit object I create line 5 is the object that I know should be in that position (with this specific dataset) after f1 is deleted. Also if I sit and debug, and manually compare objects listOfFruit[1] and f2 they are the same. But that Assert line fails. What gives?

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  • Simple Scala syntax - trying to define "==" operator - what am I missing?

    - by Alex R
    While experimenting with some stuff on the REPL, I got to a point where I needed something like this: scala class A(x:Int) { println(x); def ==(a:A) : Boolean = { this.x == a.x; } } Just a simple class with an "==" operator. Why doesn't it work??? Here's the result: :10: error: type mismatch; found : A required: ?{val x: ?} Note that implicit conversions are not applicable because they are ambiguous: both method any2ArrowAssoc in object Predef of type [A](x: A)ArrowAssoc[A] and method any2Ensuring in object Predef of type [A](x: A)Ensuring[A] are possible conversion functions from A to ?{val x: ?} class A(x:Int) { println(x); def ==(a:A) : Boolean = { this.x == a.x; } } ^ This is scala 2.8 RC1. Thanks

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  • why Observable snapshot observer vector

    - by han14466
    In Observable's notifyObservers method, why does the coder use arrLocal = obs.toArray();? Why does not coder iterate vector directly? Thanks public void notifyObservers(Object arg) { Object[] arrLocal; synchronized (this) { /* We don't want the Observer doing callbacks into * arbitrary code while holding its own Monitor. * The code where we extract each Observable from * the Vector and store the state of the Observer * needs synchronization, but notifying observers * does not (should not). The worst result of any * potential race-condition here is that: * 1) a newly-added Observer will miss a * notification in progress * 2) a recently unregistered Observer will be * wrongly notified when it doesn't care */ if (!changed) return; arrLocal = obs.toArray(); clearChanged(); } for (int i = arrLocal.length-1; i>=0; i--) ((Observer)arrLocal[i]).update(this, arg); }

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  • get content of a div from a variable using jQuery

    - by devdarsh
    i am building a php form with ajax and i am submitting the form variables to the same page where the form resides. my validating code looks like if($valid){ echo "<div id='retmsg'>Your message has been submitted successfully</div>"; } else { echo "<div id='retmsg'>An error occured!</div>"; } My ajax code function form_submit() { $('#response').html('Loading...').fadeIn(); $.ajax({ type: "POST", url: "<?php $_SERVER['PHP_SELF']; ?>", data: "title=" + $('#title').val() + "&content=" + $('#contents').val(), success: function(html){ var message = $("#retmsg").html(html); alert(message); } }); } i need to alert the contents of div id "retmsg". But the alert shows me like "[Object Object]". Please help me...

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  • ADO.NET - DataRead Error

    - by user560706
    Hi, I am trying to display data from a column in my database onto my rich textbox, but I am getting mixed up between DataSet and DataReader - I know the majority of the code below is correct, I just get two lines containing errors, and I'm not sure why: // Create a connection string string ConnectionString = ("Provider=Microsoft.ACE.OLEDB.12.0;Data Source= C:\\Documents and Settings\\Harley\\Desktop\\Test.accdb"); string SQL = "SELECT * FROM Paragraph"; // create a connection object SqlConnection conn = new SqlConnection(ConnectionString); // Create a command object SqlCommand cmd = new SqlCommand(SQL, conn); conn.Open(); DataTable dt = new DataTable(); da.Fill(dt); //ERROR // Call ExecuteReader to return a DataReader SqlDataReader reader = cmd.ExecuteReader(); foreach(DataRow reader in dsRtn) //ERROR { richTextBox = richTextBox.Text + reader[0].ToString(); } //Release resources reader.Close(); conn.Close(); }

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  • How to add Items to GridView in C# Windows Store App (Win8)

    - by flexage
    To keep things simple let's just say I have a c# Windows Store Project for Windows 8 that has the following items: GridView (PlatformsGrid) List«PlatformSearchResult» (allPlatforms) DataTemplate (PlatformDataTemplate) in standardstyles.xaml allPlatforms is a collection of "PlatformSearchResult"objects populated from an online API, and has the following 3 properties: ID Name Alias I am able to add a new item to the gridview for each object that exists in my allPlatforms collection, however the items are blank and do not show the data from my objects. A quick summary of the current code looks like this: XAML Markup: <!-- Platforms Content --> <GridView x:Name="PlatformsGrid" Grid.Row="1" CanReorderItems="True" CanDragItems="True" ItemTemplate="{StaticResource PlatformDataTemplate}" > <GridView.ItemsPanel> <ItemsPanelTemplate> <WrapGrid MaximumRowsOrColumns="2" VerticalChildrenAlignment="Top" HorizontalChildrenAlignment="Center" /> </ItemsPanelTemplate> </GridView.ItemsPanel> </GridView> Data Template <!-- Platform Item Template --> <DataTemplate x:Key="PlatformDataTemplate"> <Grid Background="#FF939598" Height="250" Width="250"> <Image Source="/SampleImage.png" Stretch="UniformToFill"/> <StackPanel Orientation="Vertical" Background="#CC000000" Height="90" VerticalAlignment="Bottom"> <TextBlock Text="{Binding Name}" Margin="10,3,0,0" Width="242" Height="62" TextTrimming="WordEllipsis" TextWrapping="Wrap" HorizontalAlignment="Left"/> <TextBlock Text="{Binding Alias}" Margin="10,2,0,0" Width="186" Height="14" TextTrimming="WordEllipsis" HorizontalAlignment="Left" FontSize="9" Opacity="0.49"/> </StackPanel> </Grid> </DataTemplate> Controlling Function private async void FetchItemInfo_Loaded(object sender, RoutedEventArgs e) { // Get List of Top Games List<PlatformSearchResult> allPlatforms = new List<PlatformSearchResult>(); allPlatforms = await GamesDB.GetPlatforms(); // Dynamically Create Platform Tiles foreach (PlatformSearchResult platform in allPlatforms) { PlatformsGrid.DataContext = platform; PlatformsGrid.Items.Add(platform); } } How do I get the added items to show the appropriate object properties (ignoring the image for now), I'm just interested in populating the content of the TextBlocks. I appreciate any help anyone can provide! Thanks, Alex.

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  • JPA and aggregate functions. How do I use the result of the query?

    - by Bogdan
    Hey guys, I'm new to ORM stuff and I need some help understanding something. Let's assume I have the following standard SQL query: SELECT *, COUNT(test.testId) AS noTests FROM inspection LEFT JOIN test ON inspection.inspId = test.inspId GROUP BY inspection.inspId which I want to use in JPA. I have an Inspection entity with a one-to-many relationship to a Test entity. (an inspection has many tests) I tried writing this in JPQL: Query query = em.createQuery("SELECT insp, COUNT(???what???) FROM Inspection insp LEFT JOIN insp.testList " + "GROUP BY insp.inspId"); 1) How do I write the COUNT clause? I'd have to apply count to elements from the test table but testList is a collection, so I can't do smth like COUNT(insp.testList.testId) 2) Assuming 1 is resolved, what type of object will be returned. It will definitely not be an Inspection object... How do I use the result?

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