Trouble binding command to button in WPF

Question

I've got a button in a ribbon I've implemented and having trouble binding to a command. The ribbon is in a UserControl named AppRibbon. The AppRibon control has a public property called SelectedModule which has a property named RenameModuleCmd. When I create an event handler for the button, i call the command explicitly to make sure everything is working as shown below:

  public partial class ApplicationRibbon : UserControl {
    public ApplicationRibbon() {
      InitializeComponent();
    }

    public ModuleViewModel SelectedModule { get; set; }

    private void ButtonTool_Click(object sender, RoutedEventArgs e) {
      SelectedModule.RenameModuleCmd.Execute(null);
    }
  }

This works fine. But I obviously don't want to use the code behind model... much rather use the Command binding. So I tried the folling bindings, but nothing fired the command.

<... Command="{Binding Path=SelectedModule.RenameModuleCmd}" />
<... Command="{Binding Path=AppRibbon.SelectedModule.RenameModuleCmd}" />

I can't figure out why these won't work. I've set breakpoints on the command's CanExecute and Execute methods as well on the RenameModuleCmd property's getter, but none are hit. Ideas?

Answer 1

You need to specify what element you're binding to when developing a UserControl and binding inside it. Try:

<... Command="{Binding ElementName=AppRibbon, Path=SelectedModule.RenameModuleCmd}" />

Assuming your UserControl is named AppRibbon as your post seems to imply.