如何确定哪个 View 执行了命令

Question

I have a View called InformationView.xaml and this same View is re-used to display the same information from 3 different sources (each view has a different window title). Each View has their datacontext set the same instance of one ViewModel type. Within my ViewModel class, I have an ICommand property that the 'Close' button inside the View is bound to. -- Is there a way to determine who the sender was of the command? (specifically, by window title).

Here is an example:

I have a view class with the following button ("Note: each View will have a different window title / display data from a different source--but the same View is used)

<Button Width="75" Height="23" Margin="0,0,5,5" Content="Close" Command="{Binding CloseCommand}" />

I have a ViewModel class with the following command

    public ICommand CloseCommand
    {
        get
        {
            if (this._closeCommand == null)
            {
                this._closeCommand = new RelayCommand(Command => this.OnClose());
            }     
            return _closeCommand;
        }
    }

I am looking for a way to determine which window executed the command (I will have multiple instances of the View using the same ViewModel).

Answer 1

I'm not sure if I understand you correctly. However, you could possibly implement the Unloaded event. Set a breakpoint inside that event method and when you hit the breakpoint. You could check the window title property for that view.

Answer 2

What about just making the Close() method public so that other objects can specify what the close behavior should be?

Something along the lines of this in your InformationViewModel :

public event EventHandler RequestClose;

void OnRequestClose()
{
    EventHandler handler = this.RequestClose;
    if (handler != null)
        handler(this, EventArgs.Empty);
}

Then you can use it from within your other view models like this:

InformationViewModel.Close += CloseMethod;

public CloseMethod(object sender, EventArgs e)
{
    // Implement close logic here
}