private IntPtr WmHcHitTest(IntPtr lparam, ref bool handled)
{
if (PresentationSource.FromDependencyObject(this) == null)
{
return(new IntPtr(0));
}
var point1 = new Point(NativeMethods.GetXlParam(lparam.ToInt32()),
NativeMethods.GetYlParam(lparam.ToInt32()));
var point2 = PointFromScreen(point1);
DependencyObject visualHit = null;
VisualUtilities.HitTestVisibleElements(this,
target =>
{
visualHit = target.VisualHit;
return(HitTestResultBehavior.Stop);
}, new PointHitTestParameters(point2));
var num = 0;
for (; visualHit != null; visualHit = visualHit.GetVisualOrLogicalParent1())
{
var nonClientArea = visualHit as INonClientArea;
if (nonClientArea == null)
{
continue;
}
num = nonClientArea.HitTest(point1);
if (num != 0)
{
break;
}
}
if (num == 0)
{
num = 1;
}
handled = true;
return(new IntPtr(num));
}