RelayCommand not firing from Context Menu item in a user control-CodePudding

In a user control I have context menu for data grid like shown below

<DataGrid.ContextMenu>
     <ContextMenu Focusable="False">
         <menuItems:ExportMenuItemView DataContext="{Binding ExportMenuItemVM}"/>
     </ContextMenu>
</DataGrid.ContextMenu>

in the view model class I have the view property

public ExportMenuItemViewModel ExportMenuItemVM {get;set;}

ExportMenuItemView is a user control which contains a menu item

<UserControl x:Class="MenuControl.View.ExportMenuItemView"
             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="20" d:DesignWidth="200">
    <MenuItem Header="Export" Focusable="False" Command="{Binding Export}"/>
</UserControl>

Below is the view model class for the Export View

namespace MenuControl.ViewModel
{
    [AddINotifyPropertyChangedInterface]
    public class ExportMenuItemViewModel : ViewModelBase
    {
        public ExportBlockMenuItemViewModel(IExport exporter)
        {
            Export = new RelayCommand(() => exporter.Export());
        }
        public RelayCommand Export { get; set; }
    }
}

RelayCommand Export is not getting executed when I click the menu item "Export". I am using MVVLLight

CodePudding user response：

I think you are missing something related to the DataContext Binding in your xaml like :

<UserControl x:Class="MenuControl.View.ExportMenuItemView"
             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="20" d:DesignWidth="200"
DataContext="{Binding Main, Source={StaticResource Locator}}">
    <MenuItem Header="Export" Focusable="False" Command="{Binding Export}"/>
</UserControl>

ViewModels in ViewModelLocator MVVM Light

CodePudding user response：

In your app.xaml add the following resource:

<Application x:Class="WpfApp1.App"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:local="clr-namespace:WpfApp1"
             StartupUri="MainWindow.xaml">
    <Application.Resources>
        <ResourceDictionary>
            <DataTemplate DataType="{x:Type local:ExportMenuItemViewModel}">
                <local:ExportMenuItemView />
            </DataTemplate>
        </ResourceDictionary>
    </Application.Resources>
</Application>