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Get property value WPF

I am trying get a value from a property but isn't working I always get a null value.
string imageNormal;
public static readonly DependencyProperty ImageNormalProperty =
DependencyProperty.Register("ImageNormal", typeof(string), typeof(MainWindow));
public string ImageNormal
{
get { return (string)GetValue(ImageNormalProperty); }
set { SetValue(ImageNormalProperty, value); }
}
public ButtonImageStyle()
{
InitializeComponent();
DataContext = this;
Console.WriteLine("Path: " + ImageNormal);
}
Xaml ButtonImageStyle.xaml:
<Image Source="{Binding ImageNormal}" Stretch="None" HorizontalAlignment="Center" VerticalAlignment="Center" />
Xaml MainWindow.xaml:
<local:ButtonImageStyle HorizontalAlignment="Left" Height="60" VerticalAlignment="Top" Width="88" ImageNormal="C:/Users/Xafi/Desktop/add.png"/>
I always obtain next output:
Path:

since your ImageSource is have to be binded to it's parent DependencyProperty (which is defined to your code behind), you have to define your binding to be rlative to your UserControl (let's name it This). Thus please try to change your xaml in the next way:
Xaml code
<UserControl x:Class="SomeBindingExampleSOHelpAttempt.ButtonImageStyle"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300" x:Name="This">
<Grid>
<Image Source="{Binding ElementName=This, Path=ImageNormal, UpdateSourceTrigger=PropertyChanged}"
Stretch="None" HorizontalAlignment="Center" VerticalAlignment="Center" />
</Grid></UserControl>
Here you can find an additional perfect answer.
Regards.

What is the datacontext of the user control?

I have a user control like so:
<Grid>
<StackPanel Orientation="Vertical">
<TextBlock Text="{Binding NameC}" Width="100" />
<TextBlock Text="{Binding Filename}" />
</StackPanel>
</Grid>
with DP in code behind:
public TestUc()
{
InitializeComponent();
DataContext = this;
}
public static readonly DependencyProperty NameCProperty = DependencyProperty.Register(
"NameC", typeof(string), typeof(TestUc), new PropertyMetadata(default(string)));
public string NameC
{
get { return (string) GetValue(NameCProperty); }
set { SetValue(NameCProperty, value); }
}
public static readonly DependencyProperty FilenameProperty = DependencyProperty.Register(
"Filename", typeof (string), typeof (TestUc), new PropertyMetadata(default(string)));
public string Filename
{
get { return (string) GetValue(FilenameProperty); }
set { SetValue(FilenameProperty, value); }
}
Now, when using it in a window,
this works fine:
<Window x:Class="TestDpOnUc.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:uc="clr-namespace:TestDpOnUc"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<uc:TestUc NameC="name is xxx" Filename="This is filename" />
</Grid>
But This does not:
<Window x:Class="TestDpOnUc.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:uc="clr-namespace:TestDpOnUc"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<uc:TestUc NameC="{Binding Name}" Filename="{Binding FileName}" />
</Grid>
public MainWindow()
{
InitializeComponent();
DataContext = this;
Name = "name is nafsafd";
FileName = "lkjsfdalkf";
}
private string _Name;
public string Name
{
get { return _Name; }
set
{
_Name = value;
OnPropertyChanged();
}
}
private string _FileName;
public string FileName
{
get { return _FileName; }
set
{
_FileName = value;
OnPropertyChanged();
}
}
Can someone please explain why? Why is the datacontext of the user control not automatically set to the parent - the main window?

It's because of this line DataContext = this in UserControl constructor. You set DataContext to your user control which affects default binding context for TestUc and all children, including <uc:TestUc ... />. So at the moment
<uc:TestUc NameC="{Binding Name}" Filename="{Binding FileName}" />
will look for Name and FileName properties inside UserControl. You need to remove that line but that will break bindings within the user control.
<TextBlock Text="{Binding NameC}" Width="100" />
<TextBlock Text="{Binding Filename}" />
Will look for NameC and Filename in MainWindow. Solution to that is to change binding context, per binding, via either RelativeSource or ElementName binding inside UserControl
<UserControl ... x:Name="myUserControl">
<Grid>
<StackPanel Orientation="Vertical">
<TextBlock Text="{Binding ElementName=myUserControl, Path=NameC}" Width="100" />
<TextBlock Text="{Binding ElementName=myUserControl, Path=Filename}" />
</StackPanel>
</Grid>
</UserControl>

When creating a UserControl with DependencyProperties you have to bind your DP's within your UserControl with ElementName- or RelativeSource Binding to your Controls in your UserControl
<TextBlock Text="{Binding ElementName=myUserControl, Path=NameC}" Width="100" />
and you never set the DataContext.
DataContext = this; <-- do not do that within your UserControl
When you wanna use your UserControl you put it in your View and bind the Properties of your actual DataContext/Viewmodel to the DependencyProperties of the UserControl.
<uc:TestUc NameC="{Binding Name}" Filename="{Binding FileName}" />

Whe you are doing <uc:TestUc NameC="{Binding Name}" Filename="{Binding FileName}" /> its not looking at MainWindow's data context instead at your UserControl's data context.
So you might want to search for the right element and bind it. Below is one way to do it using ElementName by giving a name to Window like MainWindowName. Or you can also use relative source to search for its ancestor.
<Window x:Class="TestDpOnUc.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:uc="clr-namespace:TestDpOnUc"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525"
x:Name="MainWindowName">
<Grid>
<uc:TestUc NameC="{Binding Element=MainWindowName, Path=DataContext.Name}" Filename="{Binding Element=MainWindowName, Path=DataContext.FileName}" />
</Grid>

How to raise event at Mainwindow

I have usercontrol which has datagrid .This usercontrol is added to WPF main window.I am handling gridrow selection changed event through bubble event.
<ListBox x:Name="myListBox" Grid.Row="0"
ItemsSource="{Binding Path=_myControl}"
ScrollViewer.VerticalScrollBarVisibility="Auto"
SelectedItem="{Binding CurrentItem}" SelectedIndex="1">
<ListBox.ItemTemplate>
<DataTemplate>
<Grid>
<local:UCSearchEntity GridRowSelectionConfirmed="{Binding Path=UCSearchEntity_GridRowSelectionConfirmed}" />
</Grid>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
public class MyViewModel:INotifyPropertyChanged
{
}
the error is Provide value on 'System.Windows.Data.Binding' threw an exception.
How can I access this usercontrol event in my mainwindow viewModel ?

You cannot do binding to events like that you have to do something like this on your mainwindow :
<Window DataGrid.GridRowSelectionConfirmed="GridRowSelectionConfirmed">
and GridRowSelectionConfirmed would be a method in your mainwindow
And the xaml above is a snippet in your xaml of the mainwindow.
If you want to stick to using MVVM then you have to start using behaviours but this is a more advanced concept. The behaviour is needed to attach a command that you can databind to an event that otherwise is not bindable like you were trying to do. You see I am making use of interactivity, if you want to do the same you need the blend sdk. An example :
public class AddingNewItemBehavior : Behavior<DataGrid>
{
public static readonly DependencyProperty CommandProperty
= DependencyProperty.Register("Command", typeof(ICommand), typeof(AddingNewItemBehavior), new PropertyMetadata());
public ICommand Command
{
get { return (ICommand)GetValue(CommandProperty); }
set { SetValue(CommandProperty, value); }
}
protected override void OnAttached()
{
AssociatedObject.AddingNewItem += AssociatedObject_OnAddingNewItem;
}
private void AssociatedObject_OnAddingNewItem(object sender, AddingNewItemEventArgs addingNewItemEventArgs)
{
AddingNewItem addingNewItem = new AddingNewItem();
Command.Execute(addingNewItem);
addingNewItemEventArgs.NewItem = addingNewItem.NewItem;
}
}
This is an adding new behaviour I have on a datagrid.
And this is a simplified example where i make use of that behaviour :
<UserControl x:Class="Interstone.Configuratie.Views.GraveerFiguurAdminUserControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
xmlns:iCeTechControlLibrary="clr-namespace:ICeTechControlLibrary;assembly=ICeTechControlLibrary"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<Grid>
<DataGrid ItemsSource="{Binding ZandstraalImageTypes.View}" AutoGenerateColumns="False"
VerticalGridLinesBrush="#FFC9CACA" HorizontalGridLinesBrush="#FFC9CACA" RowHeaderWidth="50"
>
<i:Interaction.Behaviors>
<iCeTechControlLibrary:AddingNewItemBehavior Command="{Binding AddingNewCommand}"/>
</i:Interaction.Behaviors>
<DataGrid.Columns>
<DataGridTextColumn Header="Categorie" Binding="{Binding TypeNaam}" Width="*"/>
</DataGrid.Columns>
</DataGrid>
</Grid>

Binding Command on ContextMenuItem

I'm having trouble with binding a ContextMenuItem's command to my parent object. I've followed the following examples:
http://www.codeproject.com/Articles/162784/WPF-ContextMenu-Strikes-Again-DataContext-Not-Upda
RelativeSource binding from a ToolTip or ContextMenu
WPF: Binding a ContextMenu to an MVVM Command
And I've got a lot closer, but I still get the following error:
System.Windows.Data Error: 40 : BindingExpression path error: 'SearchString' property
not found on 'object' ''MainWindow' (Name='root')'.
BindingExpression:Path=Parent.PlacementTarget.Tag.SearchString; DataItem='MenuItem'
(Name=''); target element is 'MenuItem' (Name=''); target property is 'Command' (type
'ICommand')
The main window class has SearchString defined as:
public partial class MainWindow : Window
{
...
private void SearchString(object sender, RoutedEventArgs e)
{
throw new NotImplementedException();
}
}
but, obviously, the exception is never getting thrown.
I have the menu defined in a DataTemplate as follows:
<Window x:Class="CodeNaviWPF.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:avalonEdit="http://icsharpcode.net/sharpdevelop/avalonedit"
Title="View" Height="865" Width="991"
x:Name="root"
>
<Window.Resources>
<DataTemplate x:Key="fileContentView">
<StackPanel>
<Border BorderThickness="3" BorderBrush="BurlyWood">
<avalonEdit:TextEditor
Width="400"
Height="400"
Document="{Binding Path=Document}"
IsReadOnly="True"
Tag="{Binding ElementName=root}">
<avalonEdit:TextEditor.ContextMenu>
<ContextMenu DataContext="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}">
<MenuItem Header="Search..." Command="{Binding Path=Parent.PlacementTarget.Tag.SearchString, RelativeSource={RelativeSource Self}}" />
</ContextMenu>
</avalonEdit:TextEditor.ContextMenu>
</avalonEdit:TextEditor>
</Border>
</StackPanel>
</DataTemplate>
</Window.Resources>
...
</Window>
Can anyone see where I'm going wrong? If I change the method to be a string property then I don't get any errors, so I'm guessing that I'm somehow telling the XAML to expect a property, rather than a method.

Answering my own question here but hopefully this will prove useful for others. The solution that worked for me was to follow the answers given here: How do I add a custom routed command in WPF?
My MainWindow now looks like the following:
namespace MyNamespace
{
public partial class MainWindow : Window
{
public MainWindow()
{
...
}
...
private void SearchString(object sender, RoutedEventArgs e)
{
throw new NotImplementedException();
}
}
public static class Commands
{
public static readonly RoutedUICommand SearchString = new RoutedUICommand("Search String", "SearchString", typeof(MainWindow));
}
}
And the XAML has the following additions:
<Window x:Class="CodeNaviWPF.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:CodeNaviWPF"
xmlns:avalonEdit="http://icsharpcode.net/sharpdevelop/avalonedit"
Title="MyApp" Height="865" Width="991"
x:Name="root"
>
<Window.CommandBindings>
<CommandBinding Command="local:Commands.SearchString" Executed="SearchString" />
</Window.CommandBindings>
<Window.Resources>
<DataTemplate x:Key="fileContentView">
<StackPanel>
<Border BorderThickness="3" BorderBrush="BurlyWood">
<avalonEdit:TextEditor
Width="400"
Height="400"
Document="{Binding Path=Document}"
IsReadOnly="True"
Tag="{Binding ElementName=root}">
<avalonEdit:TextEditor.ContextMenu>
<ContextMenu DataContext="{Binding PlacementTarget.DataContext, RelativeSource={RelativeSource Self}}">
<MenuItem Header="Search..." Command="local:Commands.SearchString" />
</ContextMenu>
</avalonEdit:TextEditor.ContextMenu>
</avalonEdit:TextEditor>
</Border>
</StackPanel>
</DataTemplate>
</Window.Resources>
...
</Window>

Combobox binding doesn't work in ItemsControl using MVVM

I have a ComboBox in ItemsControl .I use WPF and MVVM, I have problem to figure out the binding to ComboBox, would someone give me a hand for this. XAML and VM as following:
<Window x:Class="OutageManagement.Views.MarketAssignmentsView"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
Title="Market Selection"
WindowStartupLocation="CenterOwner"
Width="700" Height="850"
DataContext="{Binding MarketAssignmentsVM, Source={StaticResource Locator}}" >
<Grid>
<ItemsControl ItemsSource="{Binding USMarket}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition></ColumnDefinition>
<ColumnDefinition></ColumnDefinition>
</Grid.ColumnDefinitions>
<Label Content="{Binding MarketName}" Height="28"
HorizontalAlignment="Left" Name="lblUSMarketName"
VerticalAlignment="Center" />
<ComboBox Grid.Column="1" Height="23" HorizontalAlignment="Left"
Name="cbUSUsers" VerticalAlignment="Center" MinWidth="140"
ItemsSource="{Binding RelativeSource={RelativeSource
AncestorType=Window}, Path=UserList}"
DisplayMemberPath="UserName"
SelectedValue="{Binding SelectedUserID}"
SelectedValuePath="UserID"/>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Grid>
</Window>
ViewModel :
public class MarketAssignmentsViewModel : ViewModelBase
{
#region Data
ObservableCollection<NOCUserViewModel> _userList;
ObservableCollection<MarketAssignmentViewModel> _usMarket;
ObservableCollection<MarketAssignmentViewModel> _caMarket;
#endregion
#region Constructor
public MarketAssignmentsViewModel()
{
GetUserList();
GetMarketAssignments();
}
#endregion
#region Properties
public ObservableCollection<NOCUserViewModel> UserList
{
get { return _userList; }
}
public ObservableCollection<MarketAssignmentViewModel> USMarket
{
get { return _usMarket; }
}
public ObservableCollection<MarketAssignmentViewModel> CAMarket
{
get { return _caMarket; }
}
#endregion
.
.
.
}

The problem is that you're trying to access the UserList as a property of the Window, instead of a property of the Window's DataContext...
Modify the ItemsSource like this:
<ComboBox ItemsSource="{Binding RelativeSource={RelativeSource FindAncestor
AncestorType=Window}, Path=DataContext.UserList}" ... />
I recommend always looking in the Output window when you have binding problems, you probably would have seen something like this:
System.Windows.Data Error: 40 : BindingExpression path error: 'UserList' property not found on 'object' ''MarketAssignmentsView' (Name='')'.