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[英]How to set a binding in WPF Toolkit Datagrid's ContextMenu CommandParameter
[英]WPF Contextmenu itemtemplate commandParameter binding returns null
我有個問題。 我正在嘗試使用wpf中的數據綁定創建上下文菜單。 上下文菜單項將綁定到可觀察對象的集合。 上下文菜單的填充很好-但是,我想向其中添加命令。
我使用它的方式是:
在XAML中
<Grid.Resources>
<local:RestoreCommand x:Key="RestoreCommand" />
<local:ShowBalloonCommand x:Key="BaloonCommand" />
<local:StartTaskCommand x:Key="StartTaskCommand" />
</Grid.Resources>
<ContextMenu ItemsSource="{Binding}" Name="taskBarContextMenu">
<ContextMenu.ItemContainerStyle>
<Style TargetType="MenuItem">
<Setter Property="Command" Value="{StaticResource StartTaskCommand}"/>
<Setter Property="CommandParameter" Value="{Binding mainWindow}"/>
</Style>
</ContextMenu.ItemContainerStyle>
和
<TextBlock TextWrapping="Wrap" Text="{Binding Name}" Grid.Column="0"/>
<TextBlock TextWrapping="Wrap" Text="{Binding TimeElapsed, Mode=TwoWay,UpdateSourceTrigger=PropertyChanged}" Grid.Column="2"/>
並在C#中:
taskbarIcon.ContextMenu.ItemsSource = TasksList;
我有一個命令類
public class StartTaskCommand : ICommand
{
public void Execute(object parameter)
{
//THE PARAMETER IS ALWAYS NULL
var window = parameter as MainWindow;
if (window != null)
{
}
}
public bool CanExecute(object parameter)
{
return true;
}
public event EventHandler CanExecuteChanged;
}
我為其他兩個命令類似地設置了它,並且工作正常。 我嘗試添加為參數的任何內容始終為null-無論是taskBarContextMenu還是mainWindow或menuItem ...任何想法,歡迎您。
====
我按照建議嘗試了以下解決方案,但command參數仍然為null:
<tb:TaskbarIcon Name="taskbarIcon"
DoubleClickCommand="{StaticResource RestoreCommand}"
DoubleClickCommandParameter="{Binding ElementName=mainWindow}"
LeftClickCommand="{StaticResource BaloonCommand}"
LeftClickCommandParameter="{Binding ElementName=mainWindow}"
IconSource=".\256px-Out_of_date_clock_icon.ico"
MenuActivation="RightClick"
Tag="{Binding ElementName=mainWindow}"
>
<tb:TaskbarIcon.ContextMenu ><ContextMenu DataContext="{Binding Path=PlacementTarget.Tag, RelativeSource={RelativeSource Self}}" Tag="{Binding}" Name="taskBarContextMenu">
<ContextMenu.ItemContainerStyle>
<Style TargetType="MenuItem">
<Setter Property="Command" Value="{StaticResource StartTaskCommand}"/>
<Setter Property="CommandParameter" Value="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ContextMenu}}, Path=PlacementTarget.DataContext}"/>
</Style>
</ContextMenu.ItemContainerStyle>
看起來你的ans是這個
本文談一些已知問題。
您需要在菜單的容器中添加標簽,然后使用放置目標將其綁定。
查看此示例:
<StackPanel x:Key="ConfigurationListItem" x:Shared="False" Tag="{Binding ElementName=UserControl}">
<StackPanel Orientation="Horizontal">
<Button>
<Button.InputBindings>
<MouseBinding Gesture="LeftDoubleClick" Command="{Binding ElementName=UserControl, Path=LaunchCommand}" CommandParameter="{Binding}" />
<MouseBinding Gesture="LeftClick" Command="{Binding ElementName=UserControl, Path=SelectCommand}" CommandParameter="{Binding}" />
</Button.InputBindings>
</StackPanel>
<StackPanel.ContextMenu>
<ContextMenu DataContext="{Binding Path=PlacementTarget.Tag, RelativeSource={RelativeSource Self}}" Tag="{Binding}">
<MenuItem Header="Sync Environment Dependencies"
Command="{Binding Parent.PlacementTarget.Tag.SyncEnvironmentCommand, RelativeSource={RelativeSource Self}}"
CommandParameter="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ContextMenu}}, Path=PlacementTarget.DataContext}" />
</ContextMenu>
</StackPanel.ContextMenu>
</StackPanel>
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