The [`mc:Ignorable`][1] namespace provides xaml definitions that are &quot;ignored&quot; by the xaml processor.

This allows you to specify information used by the designer at design time which is ignored at runtime.  In your case, you can specify `DesignHeight` and `DesignWidth`, which are not &quot;real&quot; properties on a `Window`, but work in the designer for providing a default design time experience.


  [1]: http://msdn.microsoft.com/en-us/library/aa350024.aspx

`mc:Ignorable=&quot;d&quot;` sets `d:` prefix as a mark for attributes used in design. Read more on MSDN: [`mc:Ignorable` Attribute][1]

`d:DesignHeight=&quot;500&quot;` and `d:DesignWidth=&quot;300&quot;` use that `d:` prefix, what makes them available only during design time - they are ignored after standard program compilation.


  [1]: http://msdn.microsoft.com/en-us/library/aa350024.aspx

This a predefined `namespace` in WPF to be used in design-time,r but will be ignored when actually compiled and executed. It will display your design-time choices but has no effect on the actual layout.  

There is an [article](https://web.archive.org/web/20130730215413/http://geekswithblogs.net/lbugnion/archive/2010/02/01/quick-tip-commenting-out-properties-in-xaml.aspx) on the topic.

I&#39;m seeing some really strange perf related to a very simple query using Entity Framework Code-First with .NET framework version 4. The LINQ2Entities query looks like this:

     context.MyTables.Where(m =&gt; m.SomeStringProp == stringVar);

This takes over 3000 milliseconds to execute. The generated SQL looks very simple:

     SELECT [Extent1].[ID], [Extent1].[SomeStringProp], [Extent1].[SomeOtherProp],
     ...
     FROM [MyTable] as [Extent1]
     WHERE [Extent1].[SomeStringProp] = &#39;1234567890&#39;

This query runs almost instantaneously when run through Management Studio. When I change the C# code to use the SqlQuery function, it runs in 5-10 milliseconds:

     context.MyTables.SqlQuery(&quot;SELECT [Extent1].[ID] ... WHERE [Extent1].[SomeStringProp] = @param&quot;, stringVar);

So, exact same SQL, the resulting entities are change-tracked in both cases, but wild perf difference between the two. What gives?

Entity Framework query slow, but same SQL in SqlQuery is fast

How can I check with the command line the latest commit hash of a particular Git branch?


Command to get latest Git commit hash from a branch

What does `mc:Ignorable=&quot;d&quot;` mean in WPF?

And this row:    

    d:DesignHeight=&quot;500&quot; 
    d:DesignWidth=&quot;300&quot;

What does mc:Ignorable=&quot;d&quot; mean in WPF?

What does <code>mc:Ignorable="d"</code> mean in WPF?
And this row:
<pre><code class="hljs language-ini">d:DesignHeight="500" 
d:DesignWidth="300"
</code></pre>

I am starting to learn nullable types and ran into following behavior.

While trying nullable int, i see comparison operator gives me unexpected result. For example, In my code below, The output i get is **&quot;both  and 1 are equal&quot;**. Note, it does not print &quot;null&quot; as well. 


    int? a = null;
    int? b = 1;

    if (a &lt; b)
        Console.WriteLine(&quot;{0} is bigger than {1}&quot;, b, a);
    else if (a &gt; b)
        Console.WriteLine(&quot;{0} is bigger than {1}&quot;, a, b);
    else
        Console.WriteLine(&quot;both {0} and {1} are equal&quot;, a, b);

I was hoping any non-negative integer would be greater than null, Am i missing something here?




How does comparison operator works with null int?

My application needs to read data from an excel file. I am using .Net and c# for development. 
I cannot install MS office in the system. Because of that the my application fails to read excel file and throws an error while loading the dll for excel. 

How can i access excel file in my application in a system where ms office is not installed?

How to read data from excel file using c#

In my test, I defined as data a `List&lt;IUser&gt;` with some record in.

I&#39;d like setup a moq the methode `Update`, this method receive the user `id` and the `string` to update.

Then I get the the `IUser` and update the property `LastName`

I tried this :

    namespace Tests.UnitTests
    {
        [TestClass]
        public class UsersTest
        {
            public IUsers MockUsersRepo;
            readonly Mock&lt;IUsers&gt; _mockUserRepo = new Mock&lt;IUsers&gt;();
            private List&lt;IUser&gt; _users = new List&lt;IUser&gt;();
    
            [TestInitialize()]
            public void MyTestInitialize()
            {
                _users = new List&lt;IUser&gt;
                    {
                        new User { Id = 1, Firsname = &quot;A&quot;, Lastname = &quot;AA&quot;, IsValid = true },
    					new User { Id = 1, Firsname = &quot;B&quot;, Lastname = &quot;BB&quot;, IsValid = true }
                    };
    
    			Mock&lt;IAction&gt; mockUserRepository = new Mock&lt;IAction&gt;();
    			_mockUserRepo.Setup(mr =&gt; mr.Update(It.IsAny&lt;int&gt;(), It.IsAny&lt;string&gt;()))
    				.Returns(???);
    				
                MockUsersRepo = _mockUserRepo.Object;
            }
    
            [TestMethod]
            public void Update()
            {
    			//Use the mock here
            }
    
        }
    }
	
But I get this error : *cannot resolve Returns symbole*

Do you have an id ?

    class User : IUser
    {
        public int Id { get; set; }
        public string Firsname { get; set; }
        public string Lastname { get; set; }
    	public bool IsValid { get; set; }
    }
    
    interface IUser
    {
        int Id { get; set; }
        string Firsname { get; set; }
        string Lastname { get; set; }
    	bool IsValid { get; set; }
    }
    
    interface IAction
    {
        List&lt;IUser&gt; GetList(bool isActive);
    	void Update(int id, string lastname)
    }
    
    class Action : IAction
    {
        public IUser GetById(int id)
        {
            //....
        }
        public void Update(int id, string lastname)
        {
    		var userToUpdate = GetById(id);
    		userToUpdate.LastName = lastname;
            //....
        }
    }

Mock an update method returning a void with Moq

Here is the problem. I am getting IEnumerable from ViewPage and when I tried it to convert List it is showing me error like:

&gt; &#39;`System.Collections.Generic.IEnumerable&lt;Pax_Detail&gt;`&#39; does not contain
&gt; a definition for &#39;ToList&#39; and no extension method &#39;ToList&#39; accepting a
&gt; first argument of type
&gt; &#39;`System.Collections.Generic.IEnumerable&lt;Pax_Detail&gt;`&#39; could be found
&gt; (are you missing a using directive or an assembly reference?)

Here is my controller code:

    [HttpPost]
    public ActionResult Edit_Booking(Booking model, IEnumerable&lt;Pax_Detail&gt; pax)
    {
      List&lt;Pax_Detail&gt; paxList = new List&lt;Pax_Detail&gt;();
      paxList = pax.ToList(); //getting error here
      BookingDL.Update_Booking(model, paxList);
      return View();
    }

I have applied same logic on another controller. And it is working fine. I don&#39;t know what problem it has. I have already clean, rebuild project and also restarted my laptop(though it was needed).

System.Collections.Generic.IEnumerable&#39; does not contain any definition for &#39;ToList&#39;

I have a visual studio solution.
I have many projects in the solution.
There is one main project which acts as the start up and uses other projects.
There is one project say &quot;ProjectX&quot;. Its reference is added to main project.
The ProjectX references another .NET dll (say abc.dll) that isn&#39;t part of the solution. 

Now this abc.dll should be copied to bin/debug folder of main project, but it isn&#39;t getting copied there. Why is it not getting copied, any known reasons ?



Dependent DLL is not getting copied to the build output folder in Visual Studio

A common senario: A model with a collection of item models.  
E.g a House with a collection of People.

**How to structure this correctly for MVVM - particulary with regard to updating the Model and ViewModel collections with additions and deletes?**

Model `House` contains a collection of model `People` (normally a `List&lt;People&gt;`).  
View model `HouseVM` contains the House object that it wraps and an ObservableCollection of view model `PeopleVM` (`ObservableCollection&lt;PeopleVM&gt;`).  Note that we end up here with the HouseVM holding two collections (that require syncing):  
1. `HouseVM.House.List&lt;People&gt;`  
2. `HouseVM.ObservableCollection&lt;PeopleVM&gt;`

When the House is updated with new People (add) or People leave (remove) that event must now be handled in both collections the Model House People collection **AND** the the VM HouseVM PeopleVM ObservableCollection.

**Is this structure correct MVVM?  
Is there anyway to avoid having to do the double update for Adds and Removes?**

MVVM and collections of VMs

I am developing a WPF application which will be displayed in Full screen.
In addition, the application should work on many tablets of multiple dimensions.
I&#39;d like my application to run in full screen independently from its dimensions.

What is the best practice to accomplish this task?

Full screen in WPF application

Im creating a Login using a `window control` to allow a user to login into a `WPF` application that I am creating. 

So far, I have created a method that checks whether the user has entered in the correct credentials for the `username` and `password` in a `textbox` on the login screen, `binding` two `properties`. 

I have achieved this by creating a `bool` method, like so;

    public bool CheckLogin()
    {
        var user = context.Users.Where(i =&gt; i.Username == this.Username).SingleOrDefault();

        if (user == null)
        {
            MessageBox.Show(&quot;Unable to Login, incorrect credentials.&quot;);
            return false;
        }
        else if (this.Username == user.Username || this.Password.ToString() == user.Password)
        {
            MessageBox.Show(&quot;Welcome &quot; + user.Username + &quot;, you have successfully logged in.&quot;);

            return true;
        }
        else
        {
            MessageBox.Show(&quot;Unable to Login, incorrect credentials.&quot;);
            return false;
        }
    }

    public ICommand ShowLoginCommand
    {
        get
        {
            if (this.showLoginCommand == null)
            {
                this.showLoginCommand = new RelayCommand(this.LoginExecute, null);
            }
            return this.showLoginCommand;
        }
    }

    private void LoginExecute()
    {
        this.CheckLogin();
    } 

I also have a `command` that I `bind` to my button within the `xaml` like so;

    &lt;Button Name=&quot;btnLogin&quot; IsDefault=&quot;True&quot; Content=&quot;Login&quot; Command=&quot;{Binding ShowLoginCommand}&quot; /&gt;

When I enter in the username and password it executes the appropriated code, whether it being right, or wrong. But how can I close this window from the ViewModel when both username and password are correct?

I have previously tried using a `dialog modal` but it didn&#39;t quite work out. Furthermore, within my app.xaml, I have done something like the following, which loads the login page first, then once true, loads the actual application.

    private void ApplicationStart(object sender, StartupEventArgs e)
    {
        Current.ShutdownMode = ShutdownMode.OnExplicitShutdown;

        var dialog = new UserView();

        if (dialog.ShowDialog() == true)
        {
            var mainWindow = new MainWindow();
            Current.ShutdownMode = ShutdownMode.OnMainWindowClose;
            Current.MainWindow = mainWindow;
            mainWindow.Show();
        }
        else
        {
            MessageBox.Show(&quot;Unable to load application.&quot;, &quot;Error&quot;, MessageBoxButton.OK);
            Current.Shutdown(-1);
        }
    }

**Question: How can I close the Login `Window control` from the ViewModel?**

Thanks in advance.

Close Window from ViewModel

I&#39;m banging my head on my desk with this binding error..  I have checked several of the postings for the `BindingExpression` path error and cannot see anything that works with my situation.


Anyway, I have a custom control called `IncrementingTextBox`.  I am trying to disable it whenever the user &#39;checks&#39; the `CheckBox` above it.

I have a binding on the `CheckBox` `IsChecked` property that is working fine and is firing when it is supposed to.  It is correctly setting the `UseSensorLength` property on the ConfigurationModel.

However, the binding on the `IncrementingTextBox` `IsEnabled` property is causing a `BindingExpression` path error and so doesn&#39;t update at all.

As a test, I tried in the code behind to enable and disable the control and it works just fine, but I can&#39;t seem to get the Binding to work on it.

Here is a snippet from my xaml:



    ...
    
    DataContext=&quot;{Binding RelativeSource={RelativeSource Self}}&quot;
    
    ...
    ...
    
    &lt;CheckBox Content=&quot;Use Sensor Length&quot; Margin=&quot;30,6,0,0&quot; 
              IsChecked=&quot;{Binding ConfigurationModel.UseSensorLength, Mode=TwoWay}&quot;/&gt;
    
    &lt;local:IncrementingTextBox x:Name=&quot;video_length_textbox&quot; Margin=&quot;0,0,0,5&quot; 
                               IsTextEnabled=&quot;False&quot; 
                               IsEnabled=&quot;{Binding ConfigurationModel.DontUseSensorLength}&quot; 
                               ValueChanged=&quot;VideoEventValueChanged&quot;/&gt;

And Here is a snippet from my ConfigurationModel:


    public bool DontUseSensorLength
    {
        get { return !UseSensorLength; }
    }
    
    public bool UseSensorLength
    {
       get { return _useSensorLength; }
       set 
       { 
          _useSensorLength = value; 
          OnPropertyChanged(&quot;UseSensorLength&quot;); 
          OnPropertyChanged(&quot;DontUseSensorLength&quot;);
       }
    }


Here is the error message I am getting in my output window when running the app:

&gt; System.Windows.Data Error: 40 : BindingExpression path error:
&gt; &#39;ConfigurationModel&#39; property not found on &#39;object&#39;
&gt; &#39;&#39;IncrementingTextBox&#39; (Name=&#39;video_length_textbox&#39;)&#39;.
&gt; BindingExpression:Path=ConfigurationModel.DontUseSensorLength;
&gt; DataItem=&#39;IncrementingTextBox&#39; (Name=&#39;video_length_textbox&#39;); target
&gt; element is &#39;IncrementingTextBox&#39; (Name=&#39;video_length_textbox&#39;); target
&gt; property is &#39;IsEnabled&#39; (type &#39;Boolean&#39;)



Remember, the &#39;UseSensorLength&#39; property binding is working fine, but the &#39;DontUseSensorLength&#39; binding is causing the above &#39;BindingExpression path error&#39;.


WPF Error 40 BindingExpression path error: property not found on &#39;object&#39;

I was working on creating some markup extensions and started to get very weird VS behaviours. I have extracted and pinpointed the issue in the separate solution. Problem is that VS can&#39;t create a CLR object in XAML. 

Here it is:

**View:**

    &lt;Window x:Class=&quot;WpfApplication4.MainWindow&quot;
            xmlns=&quot;http://schemas.microsoft.com/winfx/2006/xaml/presentation&quot;
            xmlns:x=&quot;http://schemas.microsoft.com/winfx/2006/xaml&quot;
            xmlns:wpfApplication4=&quot;clr-namespace:WpfApplication4&quot;&gt;
        &lt;Window.Resources&gt;
            &lt;wpfApplication4:Dog x:Key=&quot;doggy&quot; /&gt;
        &lt;/Window.Resources&gt;
        &lt;Grid /&gt;
    &lt;/Window&gt;

**Code behind:**

    using System.Windows;
    
    namespace WpfApplication4
    {
        public partial class MainWindow : Window
        {
            public MainWindow()
            {
                InitializeComponent();
            }
        }
    }


**Dog class:**

    namespace WpfApplication4
    {
        public class Dog
        {
    
        }
    }

**App.Xaml (no code in App.Xaml.cs):**

    &lt;Application x:Class=&quot;WpfApplication4.App&quot;
                 xmlns=&quot;http://schemas.microsoft.com/winfx/2006/xaml/presentation&quot;
                 xmlns:x=&quot;http://schemas.microsoft.com/winfx/2006/xaml&quot;
                 StartupUri=&quot;MainWindow.xaml&quot;&gt;
        &lt;Application.Resources&gt;
             
        &lt;/Application.Resources&gt;
    &lt;/Application&gt;

![Project settings][1]

Exception I am getting:

    Error	1	The name &quot;Dog&quot; does not exist in the namespace &quot;clr-namespace:WpfApplication4&quot;.	\\hopr1\folders$\vxk\Documents\Visual Studio 2012\Projects\WpfApplication4\MainWindow.xaml	6	9	WpfApplication4

I am able to run solution, but designer fails with &quot;Invalid Markup&quot; error
Any ideas?

**Edit**

I am running VS 2012 Update 2
The same solution work in VS 2012 Update 1

  [1]: http://i.stack.imgur.com/HyMzZ.png
  [2]: http://i.stack.imgur.com/gf6o5.png
  [3]: http://i.stack.imgur.com/W6xTg.png


The name &quot;XYZ&quot; does not exist in the namespace &quot;clr-namespace:ABC&quot;

I am currently working on my first WPF project and trying to make a `ListView` scrollable.
At first I thought this could be easily done by simply limiting the `ListView`&#39;s width and height and thus forcing a scrollbar to appear automatically whenever the content exceeds its space. This seemed fine at first but due to the handled `PreviewMouseDown` event (which enables dragging the list&#39;s items) it doesn&#39;t work after selecting an item.

**Second attempt** (using `ScrollViewer`)

    &lt;ScrollViewer&gt;
        &lt;ListView ItemsSource=&quot;{Binding FileViewModels}&quot;
                  PreviewMouseDown=&quot;ListView_MouseMove&quot;
                  Height=&quot;450&quot; Width=&quot;200&quot;/&gt;
    &lt;/ScrollViewer&gt;

Of course, this resulted in a second scrollbar whenever the list&#39;s content became larger than its max height. And dragging the bar still didn&#39;t work after selecting an item.

**Third** (quite foolish) **attempt** (disabling scrollbar duplicate)

    &lt;ScrollViewer&gt;
        &lt;ListView ItemsSource=&quot;{Binding FileViewModels}&quot;
                  PreviewMouseDown=&quot;ListView_MouseMove&quot;
                  Height=&quot;450&quot; Width=&quot;200&quot;
                  ScrollViewer.VerticalScrollBarVisibility=&quot;Disabled&quot;
                  ScrollViewer.HorizontalScrollBarVisibility=&quot;Disabled&quot;/&gt;
    &lt;/ScrollViewer&gt;

This removed the scrollbar duplicate and enabled scrolling via mouse wheel but disabled the scrollbar, so you couldn&#39;t move by clicking and dragging it.

**Fourth attempt** (constant size of the `ScrollViewer`)

    &lt;ScrollViewer Height=&quot;450&quot; Width=&quot;200&quot;&gt;
        &lt;ListView ItemsSource=&quot;{Binding FileViewModels}&quot;
                  PreviewMouseDown=&quot;ListView_MouseMove&quot;/&gt;
    &lt;/ScrollViewer&gt;

Removed the width/height constraint from the `ListView` and moved it to the `ScrollViewer`. This enables the scrollbar and removes the duplicate. Unfortunately the mouse wheel doesn&#39;t work anymore (dragging the scroll bar works fine). 

Could somebody please explain to me why the mouse wheel doesn&#39;t work anymore and how to fix this?

**Edit**
Maybe I should go back to my first solution.
    &lt;ListView ItemsSource=&quot;{Binding FileViewModels}&quot;
              PreviewMouseDown=&quot;ListView_MouseMove&quot;
              Height=&quot;450&quot; Width=&quot;200&quot;/&gt;
              
Obviously, the `ListView`&#39;s template already contains a `ScrollViewer`. The remaining problem would then be that I cannot drag the scrollbar after selecting an item because of the handled `PreviewMouseDown` event (scrolling via MouseWheel still works in that case). Should I handle the dragging of items differently (it worked fine for me, before wanting to add a scrollbar)? Or is there a way to detect if the cursor is above the scrollbar (so I could then deselect the item which enables scrolling)?
Or are there any other suggestions?

ScrollViewer mouse wheel not scrolling

In a `ListView` there are `ListviewItems` where they must not change appearance when the mouse is over them or they are selected. 

I tried to accomplish that with this style and did *somewhat* succeed:

    &lt;Style x:Key=&quot;ItemContainerStyle1&quot; TargetType=&quot;ListViewItem&quot;&gt;
        &lt;Setter Property=&quot;HorizontalContentAlignment&quot; Value=&quot;Left&quot;/&gt;
        &lt;Style.Triggers&gt;
            &lt;Trigger Property=&quot;IsMouseOver&quot; Value=&quot;True&quot;&gt;
                &lt;Setter Property=&quot;Background&quot; Value=&quot;Transparent&quot; /&gt;
                &lt;Setter Property=&quot;BorderThickness&quot; Value=&quot;0&quot; /&gt;
                &lt;Setter Property=&quot;Focusable&quot; Value=&quot;False&quot; /&gt;
            &lt;/Trigger&gt;
        &lt;/Style.Triggers&gt;
    &lt;/Style&gt;

But the it raised a new issue. When the background is set to &quot;Transparent&quot; I am now able to see this hover/glossy effect that is shown at the picture below, when the mouse is over a list view item.

![enter image description here][1]

I have tried to solve the problem with this attempt, but with no luck.

    &lt;Style TargetType=&quot;{x:Type ListViewItem}&quot;&gt;
        &lt;Style.Resources&gt;
          &lt;SolidColorBrush x:Key=&quot;{x:Static SystemColors.HighlightBrushKey}&quot; Color=&quot;#00000000&quot;/&gt;
          &lt;SolidColorBrush x:Key=&quot;{x:Static SystemColors.ControlBrushKey}&quot; Color=&quot;#00000000&quot;/&gt;
        &lt;/Style.Resources&gt;
    &lt;/Style&gt;

Anyone have an idea how to remove this hover effect?


  [1]: http://i.stack.imgur.com/CGof0.png

Content Type	Original Author	Original Content on Stackoverflow
Question	user2209075	View Question on Stackoverflow
Solution 1 - C#	Reed Copsey	View Answer on Stackoverflow
Solution 2 - C#	MarcinJuraszek	View Answer on Stackoverflow
Solution 3 - C#	bash.d	View Answer on Stackoverflow

What does mc:Ignorable="d" mean in WPF?

C# Problem Overview

C# Solutions

Solution 1 - C#

Solution 2 - C#

Solution 3 - C#

Command to get latest Git commit hash from a branch

Entity Framework query slow, but same SQL in SqlQuery is fast

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