Create a ContextMenu from xaml, per DataGrid row

[Dragorn421]

Hi,

I'm using a DataGrid and I want a different ContextMenu on each row (e.g. depending on the row's DataContext).

My current solution is using LoadingRow="OnDataGridLoadingRow" on the DataGrid element in the xaml, and in the OnDataGridLoadingRow function setting the (e as DataGridRowEventArgs).Row.ContextMenu to a new code-constructed ContextMenu instance:

    public void OnDataGridLoadingRow(object? sender, DataGridRowEventArgs e)
    {
        var cm = new ContextMenu();
        var ri = e.Row.DataContext as MainWindowViewModel.RowItem;
        cm.Items.Add(new MenuItem() { Header = "thing " + ri.ValueCol1 });
        cm.Items.Add(new MenuItem() { Header = "hey" });
        e.Row.ContextMenu = cm;
    }

This works, but I would like to define the ContextMenu in xaml as much as possible instead of having to create it and its items in code.

Here is minimal full code
https://github.com/Dragorn421/DragoStuff/tree/avalonia_contextmenu_xaml
showing

• Creating a ContextMenu and populating it with items in code, leading to the expected result (MainWindow.OnDataGridLoadingRow, upper datagrid in the window)
• Trying to create a xaml-based context menu ContextMenuTemplate (doesn't work, it does build and run without errors or any warning in the console output, but no context menu shows) (MainWindow.OnDataGridWTemplateAttemptLoadingRow, lower datagrid in the window)

Is there a better approach than using LoadingRow=?
Can a ContextMenu be created from xaml?

[timunie]

You can add a Style for DataGridRow which hold a ContextFlyout iirc.

[Dragorn421]

Thanks, using a Style selector to set DataGridRow's ContextMenu works :)
Only hurdle is x:DataType needs to be set on the ContextMenu to the rows' DataContext type

<DataGrid
    ItemsSource="{Binding MyDataGridItems}"
>
    <DataGrid.Styles>
        <Style Selector="DataGridRow">
            <Setter Property="ContextMenu">
                <ContextMenu x:DataType="vm:MainWindowViewModelRowItem">
                    <MenuItem Header="{Binding ValueCol1}" />
                    <ContextMenu.Resources>
                        <vm:MyConverter x:Key="myConverter"/>
                    </ContextMenu.Resources>
                    <MenuItem Header="{Binding ValueCol1,
                                        Converter={StaticResource myConverter},
                                        ConverterParameter='a prefix '}" />
                    <MenuItem Header="runthing" Command="{Binding RunThing}" />
                    <MenuItem Header="heyy" />
                </ContextMenu>
            </Setter>
        </Style>
    </DataGrid.Styles>
    <DataGrid.Columns>
        <DataGridTextColumn Header="Col1" Binding="{Binding ValueCol1}" />
    </DataGrid.Columns>
</DataGrid>

pushed updated example to https://github.com/Dragorn421/DragoStuff/tree/avalonia_contextmenu_xaml