Drag&Drop to DataGrid item control (get current item index)

Question

I have datagrid template and some textbox control into each row at datagrid. So, how to drag and drop into textbox on row?

I know how and what i should drop, but i do not know how to get the position of datagrid item that i should drop.

Answer 1

You can use the VisualTreeHelper.HitTest method and the VisualTreeHelper.GetParent method to find out if you're over a particular DataGridRow in the PreviewDragOver event handler:

private void PreviewDragOver(object sender, DragEventArgs e)
{
    HitTestResult hitTestResult = 
        VisualTreeHelper.HitTest(sender, e.GetPosition(sender));
    DataGridRow dataGridRowUnderMouse = 
        GetParentOfType<DataGridRow>(hitTestResult.VisualHit);
    // Do something with dataGridRowUnderMouse 
}

private T GetParentOfType<T>(DependencyObject element) where T : DependencyObject
{
    Type type = typeof(T);
    if (element == null) return null;
    DependencyObject parent = VisualTreeHelper.GetParent(element);
    if (parent == null && ((FrameworkElement)element).Parent is DependencyObject) 
        parent = ((FrameworkElement)element).Parent;
    if (parent == null) return null;
    else if (parent.GetType() == type || parent.GetType().IsSubclassOf(type)) 
        return parent as T;
    return GetParentOfType<T>(parent);
}