Currently I have in my XAML
<TabControl
AllowDrop="True"
PreviewDragOver="DragOver"
PreviewDrop="Drop" />
All of my drag/drop code exists within the codebehind of my View, rather than within my ViewModel.
How can I handle drag/drop in my ViewModel without adding any dependencies on the View?
There are libraries for this such as gong and similar snippets on various blog articles.
However, you shouldn't get too hung up on having absolutely no code-behind. For example, this is still MVVM in my book:
void ButtonClicked(object sender, EventArgs e)
{
((MyViewModel) this.DataContext).DoSomething();
}
A command binding might be a better choice, but the logic is definitely in the viewmodel. With something like Drag and Drop, it's more variable where you want to draw the line. You can have code-behind interpret the Drag Args and call methods on the viewmodel when appropriate.