Question

I’m exploring WPF and XAML for the first time, and there’s a lot I don’t yet understand.

I’m working through this: http://www.codeproject.com/KB/WPF/AvalonDockMVVM.aspx

I’ve created my own project, and am attempting to add to it code from AvalonDockMVVM.

Currently, I’m trying to construct the menu.

In MainWindow.xaml, I’ve added:

<Window.Resources>
    <RoutedUICommand x:Key="Commands.Exit" />
</Window.Resources>

<Window.CommandBindings>
    <CommandBinding Command="{StaticResource Commands.Exit}" Executed="Exit_Executed" />
</Window.CommandBindings>

<DockPanel>
    <Menu DockPanel.Dock="Top">
        <MenuItem Header="_File">
            <MenuItem Header="_Exit" Command="{StaticResource Commands.Exit}" />
        </MenuItem>
    </Menu>
    ...
</DockPanel>

The idea is to construct a menu with a single “Exit” option.

Now as I said, I hardly know what I am doing. But it looks to me like the <RoutedUICommand> is creating a command, the <CommandBinding> is binding it to the ExitExecuted() method in the code-behind, and the <MenuItem> is saying that when you select that menu item, execute whatever is bound to that command.

It all works fine, in the AvalonDockMVVM project. In mine, I’m betting errors on {StaticResource Commands.Exit}: The resource Commands.Exit could not be resolved.

That makes me think that there’s something, in code or in configuration, somewhere, that defines Commands.Exit, besides the <RoutedUICommand> element in the XAML. But for the life of me, I can’t find it.

Is there something else I need to do, in order to bind a method to a menu, through a command?

Answer 1

I literally copied your above example into a new WPF project, merely removing the ellipses and adding a method in code behind to handle the exit command. It ran just fine and had no problem resolving the command. Here’s my entire, and complete, XAML

<Window x:Class="WPFTest.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <RoutedUICommand x:Key="Commands.Exit" />
    </Window.Resources>

    <Window.CommandBindings>
        <CommandBinding Command="{StaticResource Commands.Exit}" Executed="Exit_Executed" />
    </Window.CommandBindings>
    <DockPanel>
        <Menu DockPanel.Dock="Top">
            <MenuItem Header="_File">
                <MenuItem Header="_Exit" Command="{StaticResource Commands.Exit}" />
            </MenuItem>
        </Menu>
    </DockPanel>
</Window>

There’s two places I’d look for trouble resolving the resource. First, check to see if you have a project-level static resource defined with a “Commands.Exit” key on it (or another resource further down the page). Second, look to see if code above the <RoutedUICommand> or <Window.Resources> has an un-closed tag. That should throw up a parse error, but maybe not?