private void ResizeGrid_MouseDown(object sender, MouseButtonEventArgs e)
{
if (e.LeftButton == MouseButtonState.Pressed && !resizeActive)
{
resizeActive = true;
resizeMouseStartPosition = Mouse.GetPosition(null);
resizeStartSize = new Size(((UserControl)windowContent.Content).Width, ((UserControl)windowContent.Content).Height);
ResizeGrid.CaptureMouse();
}
}
