/// <summary> /// Event handler for the <see cref="PreviewMouseLeftButtonDown"/> event /// </summary> /// <remarks> /// Occurs when the left mouse button is pressed while the mouse pointer is over this element. /// </remarks> /// <param name="sender">the sender of the event</param> /// <param name="e">the <see cref="MouseButtonEventArgs"/> associated to the event</param> private void PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e) { if (e.ClickCount != 1 || VisualTreeExtensions.HitTestScrollBar(sender, e) || VisualTreeExtensions.HitTestGridColumnHeader(sender, e)) { this.dragInfo = null; return; } this.dragInfo = new DragInfo(sender, e); }