private void WmPaint(ref Message m)
{
if (FlatStyle != FlatStyle.System)
{
return;
}
IntPtr hWnd = IntPtr.Zero;
IntPtr dc;
Rectangle clip;
NativeMethods.PAINTSTRUCT ps = new NativeMethods.PAINTSTRUCT();
bool needDisposeDC = false;
try
{
if (m.WParam == IntPtr.Zero)
{
// Cache Handle not only for perf but to avoid object disposed exception in case the window
// is destroyed in an event handler (VSW#261657).
hWnd = this.Handle;
dc = UnsafeNativeMethods.BeginPaint(new HandleRef(this, hWnd), ref ps);
if (dc == IntPtr.Zero)
{
return;
}
needDisposeDC = true;
clip = new Rectangle(ps.rcPaint_left, ps.rcPaint_top,
ps.rcPaint_right - ps.rcPaint_left,
ps.rcPaint_bottom - ps.rcPaint_top);
m_InternalPaint = true;
PaintEventArgs pevent = new PaintEventArgs(CreateGraphics(), clip);
OnPaint(pevent);
}
else
{
dc = m.WParam;
clip = ClientRectangle;
}
}
finally
{
if (needDisposeDC)
{
UnsafeNativeMethods.EndPaint(new HandleRef(this, hWnd), ref ps);
}
}
}
public static bool EndPaint(HandleRef hWnd, [In, MarshalAs(UnmanagedType.LPStruct)] ref NativeMethods.PAINTSTRUCT lpPaint)
{
Ekstrand.Internal.HandleCollector.Remove(lpPaint.hdc, NativeMethods.CommonHandles.HDC);
return(IntEndPaint(hWnd, ref lpPaint));
}
public static IntPtr BeginPaint(HandleRef hWnd, [In, Out, MarshalAs(UnmanagedType.LPStruct)] ref NativeMethods.PAINTSTRUCT lpPaint)
{
return(Ekstrand.Internal.HandleCollector.Add(IntBeginPaint(hWnd, ref lpPaint), NativeMethods.CommonHandles.HDC));
}
private static extern bool IntEndPaint(HandleRef hWnd, ref NativeMethods.PAINTSTRUCT lpPaint);
private static extern IntPtr IntBeginPaint(HandleRef hWnd, [In, Out] ref NativeMethods.PAINTSTRUCT lpPaint);