Question

I have an application build with the MVVM pattern from Josh Smith (http://msdn.microsoft.com/en-us/magazine/dd419663.aspx).

When I have several workspaces opened in my app, I want to catch the event of switching workspaces/tabs so I can save the content of the current workspace first. I have looked throught WorkspaceViewModel and ViewModelBase, but I don’t know how to add that EventHandler.

Answer 1

I have found a solution in another post, I just had to tweak it a little bit : What is the proper way to handle multiple datagrids in a tab control so that cells leave edit mode when the tabs are changed?

Basically I have added an EventHandler on PreviewMouseDown of my TabControl generating the different Workspaces.

private void TabControl_PreviewMouseDown(object sender, MouseButtonEventArgs e) {
        MainWindow_VM dc = (MainWindow_VM)this.DataContext;

        if (IsUnderTabHeader(e.OriginalSource as DependencyObject))
            //Do what need to be done before switching workspace
            // in my case, switch the focus to a dummy control so the objectContext would save everything, even the currently focused textbox

    }

private bool IsUnderTabHeader(DependencyObject control) 
    {
        if (control is TabItem)
        {
            return true;
        }
        DependencyObject parent = VisualTreeHelper.GetParent(control); 
        if (parent == null)         
            return false; 

        return IsUnderTabHeader(parent); 
    }