Is there a way to do a Mouse- or KeyBinding in a WPF treeview?
<TreeView ItemsSource="{Binding Main.TreeItems}">
<TreeView.ItemTemplate>
<HierarchicalDataTemplate ItemsSource="{Binding Path=Children}">
<TextBlock Text="{Binding Path=Header}">
<TextBlock.InputBindings>
<MouseBinding Command="{Binding TreeViewClickCommand}" MouseAction="LeftDoubleClick"/>
</TextBlock.InputBindings>
</TextBlock>
</HierarchicalDataTemplate>
</TreeView.ItemTemplate>
</TreeView>
This doesn't work. If i use my Command on a button not in the treeview then the command is fired. How can i solve this problem?
If this Command works outside the TreeView, I assume your TreeViewClickCommand is located in the DataContext of your Window/UserControl.
Use AncestorType to refer to the TreeViews DataContext (which is the same as the Windows DC, if you did not set it manuelly):
Command="{Binding RelativeSource={RelativeSource AncestorType={x:Type TreeView}}, Path=DataContext.TreeViewClickCommand}"
You can use AttachedCommandBehavior to do this.
Related
I have the following xaml code:
<ListBox Foreground="{Binding MyColor, Converter={local:ColorConverter}}" ItemsSource="{Binding LogCollection, Mode=TwoWay}" Grid.Row="1">
</ListBox>
This changes the foreground color for the entire listbox, so I modified the code in this way:
<ListBox ItemsSource="{Binding LogCollection, Mode=TwoWay}" Grid.Row="1">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Foreground="{Binding MyColor, Converter={local:ColorConverter}}" Text="{Binding}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
In this way I wanted to set the foreground for an item instead for the entire listbox, but it is not working. How do I find the right datacontext ? MyColor is a property on my MainViewModel.
LATER EDIT WITH THE SOLUTION
Jens's answer was the one that showed me where I was wrong. Instead of storing simple message log strings in the ObservableCollection, I created a new class (LogItems) which contains a Message and a Color members. Now the LogCollection is typeof LogItems instead of strings.
I populate the listbox with the following code in my viewmodel:
LogItems logitem = new LogItems(myMessage, myColor);
LogCollection.Insert(0, logitem);
And the view has the following form. Also it doesn't require anymore to use RelativeSource, because the datacontext is the same.
<ListBox ItemsSource="{Binding LogCollection, Mode=TwoWay}" Grid.Row="1">
<ListBox.ItemTemplate>
<DataTemplate>
<TextBlock Foreground="{Binding Path=Color, Converter={local:ColorConverter}}" Text="{Binding Path=Message}"/>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
Thank you all for your answers which lead me to this solution.
The DataContext of generated container in a listbox is automatically set to the corresponding item, therefore your Binding does not find the Property MyColor. You need to use a RelativeSource binding to bind to the DataContext of the containing list:
<TextBlock Foreground="{Binding DataContext.MyColor,
RelativeSource={RelativeSource
Mode=FindAncestor,
AncestorType={x:Type ListBox}},
Converter={local:ColorConverter}}"
Text="{Binding}"/>
I created a WPF application and am following MVVM Pattern. I have a context menu in my xaml and I need to bind the command and Header text. Using the following code I can bind the Header of the context menu with the "MenuItemName" which is a property in BOList which is an observable collection. My issue is that command is not getting fired? I changes the Item source of the Context Menu to datacontext
(DataContext="{Binding Path=PlacementTarget.Tag, RelativeSource={RelativeSource Self}}")
Command is working fine but my header is getting blank. Is there a way to bind my header and command of a menu item? Here the command MenuClick is a Icommand property in the VM and MenuItemName is a property inside BOList which is an observable collection binded to my ListBox.
<Grid>
<StackPanel Orientation="Vertical">
<Button x:Name="btnClickMe" Command="{Binding ButtonCommand}" Content="Click Me" />
<ListBox ItemsSource="{Binding BOList}" x:Name="lstDemo" SelectedItem="{Binding BussinessObj,Mode=OneWayToSource}">
<ListBox.ItemTemplate>
<DataTemplate>
<StackPanel x:Name="stkStyleRender" Orientation="Horizontal" Background="Cyan" Width="525" Tag="{Binding DataContext, RelativeSource={RelativeSource AncestorType={x:Type ListBox}}}" >
<TextBlock x:Name="txtId" Text="{Binding FirstName}"></TextBlock>
<TextBlock x:Name="txtName" Text="{Binding LastName}"></TextBlock>
<StackPanel.ContextMenu>
<ContextMenu x:Name="cntMnuTest" ItemsSource ="{Binding Path=PlacementTarget.Tag, RelativeSource={RelativeSource Self}}" >
<MenuItem Header="{Binding MenuItemName}" Command="{Binding MenuClick}" CommandParameter="Icon"></MenuItem>
</ContextMenu>
</StackPanel.ContextMenu>
</StackPanel>
</DataTemplate>
</ListBox.ItemTemplate>
</ListBox>
</StackPanel>
Hi Identified the issue.
If we set Item Source of the context menu to BOList (observable collection ) command wont get fired because the ICommand definition is in Window data context (vm).
We need to handle the code like wise.
Since debugging is not possible for binding , I was beating around the bush :-)
This link helped me a lot WPF Tutorial - Debug Databinding Issues in WPF
In context menu use DataContext instead of using Items source
then bind your menu item
try this:
<MenuItem Header="{Binding Path=PlacementTarget.MenuItemName, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ContextMenu}}" Command="{Binding Path=PlacementTarget.MenuClick, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ContextMenu}}" />
I currently have a UserControl that uses the MVVM model.
In that control there is a TreeView, which displays some items. I have added a HierarchicalDataTemplate for this TreeView and in that template is a ContextMenu for the Items.
In the ViewModel, which is DataContext of the control (named RestoresTreeViewControl) is a command I want to bind one of the menu items to. However what I have done doesn't seem to be working. I am getting the usual can't find source for binding reference.
Here is the bit of code for the datatemplate that tried to bind the EditDatabaseCommand to one of the menu items.
<HierarchicalDataTemplate DataType="{x:Type model:Database}" >
<StackPanel>
<TextBlock Text="{Binding Name}" >
<TextBlock.ContextMenu>
<ContextMenu>
<MenuItem Header="Edit" Command="{Binding ElementName=RestoresTreeViewControl, Path=DataContext.EditDatabaseCommand}" />
<MenuItem Header="Delete"/>
<Separator/>
<MenuItem Header="Test Connection"/>
</ContextMenu>
</TextBlock.ContextMenu>
</TextBlock>
</StackPanel>
</HierarchicalDataTemplate>
Here is a section of the ViewModel where the command is.
public ICommand EditDatabaseCommand { get; private set; }
Unfortunately the ContextMenu is not in the VisualTree, so it's not going to see your DataContext. What you can do is something like this (copied from here: MVVM binding command to contextmenu item)
<Button Height="40" Margin="0,2,0,0" CommandParameter="{Binding Name}"
Tag="{Binding RelativeSource={RelativeSource Mode=FindAncestor,
AncestorType={x:Type UserControl}}}" Command = "{Binding
RelativeSource={RelativeSource Mode=FindAncestor, AncestorType={x:Type UserControl}},
Path=DataContext.ConnectCommand}">
<Button.ContextMenu>
<ContextMenu>
<MenuItem Header="Remove"
CommandParameter="{Binding Name}"
Command="{Binding Path=PlacementTarget.Tag.DataContext.RemoveCommand,
RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ContextMenu}}"/>
</ContextMenu>
</Button.ContextMenu>
So simply use PlacementTarget.Tag to find your ViewModel.
You can try tracing the binding:
xmlns:diag="clr-namespace:System.Diagnostics;assembly=WindowsBase"
...
{binding ... diag:PresentationTraceSources.TraceLevel="High"}
However requiring the users (even if it is just yourself) of your control to name each instance of "RestoresTreeViewControl" rather burdensome.
Try:
{Binding Path=... RelativeSource={ FindAncestor, AncestorType={x:TheRestoresTreeViewControlType}} }
That probably has to do with the inheritance context.
See: Binding WPF ContextMenu MenuItem to UserControl Property vs ViewModel Property
I have an ItemsControl whose for the ItemTemplate DataTemplate contains a Button. I want the Command on the button to bind to a Command on the DataContext of the ItemsControl, not the ItemTemplate. I think the solution has to do with using RelativeSource, but my attempts so far have failed:
<ItemsControl ItemsSource="{Binding Games}">
<ItemsControl.ItemTemplate>
<DataTemplate>
<Button Command="{Binding Path=GameSelectedCommand, Source={RelativeSource FindAncestor, AncestorType={x:Type ItemsControl}}}"
CommandParameter="{Binding}"
Style="{StaticResource MenuButtonStyle}"
Content="{Binding Name}"/>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
How can I get the Button to bind to the GameSelectedCommand of the ItemsControl's DataContext object?
You're setting the source of the binding to the ItemsControl itself. Therefore, you'll need to dereference the DataContext of the ItemsControl:
Command="{Binding DataContext.GameSelectedCommand, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ItemsControl}}}"
How would you have known this? Take a look at your debug output window when running the app. You'll see a message along the lines of "Cannot resolve property 'GameSelectedCommand' on type 'ItemsControl'".
I have a list (see below) contained in a window. The window's DataContext has two properties, Items and AllowItemCommand.
How do I get the binding for the Hyperlink's Command property needs to resolve against the window's DataContext?
<ListView ItemsSource="{Binding Items}">
<ListView.View>
<GridView>
<GridViewColumn Header="Action">
<GridViewColumn.CellTemplate>
<DataTemplate>
<StackPanel>
<TextBlock>
<!-- this binding is not working -->
<Hyperlink Command="{Binding AllowItemCommand}"
CommandParameter="{Binding .}">
<TextBlock Text="Allow" />
</Hyperlink>
</TextBlock>
</StackPanel>
</DataTemplate>
</GridViewColumn.CellTemplate>
</GridViewColumn>
</GridView>
</ListView.View>
</ListView>
You could try something like this:
...Binding="{Binding RelativeSource={RelativeSource FindAncestor,
AncestorType={x:Type Window}}, Path=DataContext.AllowItemCommand}" ...
This will also work:
<Hyperlink Command="{Binding RelativeSource={RelativeSource AncestorType=ItemsControl},
Path=DataContext.AllowItemCommand}" />
ListView will inherit its DataContext from Window, so it's available at this point, too.
And since ListView, just like similar controls (e. g. Gridview, ListBox, etc.), is a subclass of ItemsControl, the Binding for such controls will work perfectly.
This also works in Silverlight 5 (perhaps earlier as well but i haven't tested it). I used the relative source like this and it worked fine.
RelativeSource="{RelativeSource Mode=FindAncestor, AncestorType=telerik:RadGridView}"