|
protected OnNonClientAreaPaint ( |
||
| e | ||
| return | void | |
private void PaintNonClientArea(IntPtr hWnd, IntPtr hRgn)
{
var windowRect = new NativeMethods.RECT();
if (NativeMethods.GetWindowRect(hWnd, ref windowRect) == 0)
{
return;
}
var bounds = new Rectangle(
0,
0,
windowRect.right - windowRect.left,
windowRect.bottom - windowRect.top
);
if (bounds.Width == 0 || bounds.Height == 0)
{
return;
}
// The update region is clipped to the window frame. When wParam
// is 1, the entire window frame needs to be updated.
Region clipRegion = null;
if (hRgn != (IntPtr)1)
{
clipRegion = Region.FromHrgn(hRgn);
}
// MSDN states that only WINDOW and INTERSECTRGN are needed,
// but other sources confirm that CACHE is required on Win9x
// and you need CLIPSIBLINGS to prevent painting on overlapping windows.
var hDC = NativeMethods.GetDCEx(
hWnd,
hRgn,
NativeMethods.DCX_WINDOW | NativeMethods.DCX_INTERSECTRGN | NativeMethods.DCX_CACHE | NativeMethods.DCX_CLIPSIBLINGS
);
if (hDC == IntPtr.Zero)
{
hDC = NativeMethods.GetWindowDC(hWnd);
}
if (hDC == IntPtr.Zero)
{
return;
}
try
{
var border = _chrome.AdjustedResizeBorderThickness;
var clientArea = new Rectangle(
border.Left,
border.Top + _chrome.CaptionHeight,
_form.Width - border.Horizontal,
_form.Height - (border.Vertical + _chrome.CaptionHeight)
);
if (!_chrome.DoubleBuffered)
{
using (Graphics graphics = Graphics.FromHdc(hDC))
{
graphics.ExcludeClip(clientArea);
// Cliping rect is not cliping rect but actual rectangle.
_chrome.OnNonClientAreaPaint(new NonClientPaintEventArgs(
graphics,
bounds,
clipRegion,
IsMaximized,
IsActive
));
}
// NOTE: The Graphics object would realease the HDC on Dispose.
// So there is no need to call NativeMethods.ReleaseDC(msg.HWnd, hDC);
// http://groups.google.pl/groups?hl=pl&lr=&c2coff=1&client=firefox-a&rls=org.mozilla:en-US:official_s&threadm=%23DDSaH7BFHA.3644%40TK2MSFTNGP15.phx.gbl&rnum=15&prev=/groups%3Fq%3DWM_NCPaint%2B%2BGetDCEx%26start%3D10%26hl%3Dpl%26lr%3D%26c2coff%3D1%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official_s%26selm%3D%2523DDSaH7BFHA.3644%2540TK2MSFTNGP15.phx.gbl%26rnum%3D15
// http://groups.google.pl/groups?hl=pl&lr=&c2coff=1&client=firefox-a&rls=org.mozilla:en-US:official_s&threadm=cmo00r%24j9v%241%40mamut1.aster.pl&rnum=1&prev=/groups%3Fq%3DDCX_PARENTCLIP%26hl%3Dpl%26lr%3D%26c2coff%3D1%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-US:official_s%26selm%3Dcmo00r%2524j9v%25241%2540mamut1.aster.pl%26rnum%3D1
}
else
{
// http://www.codeproject.com/csharp/flicker_free.asp
// http://www.pinvoke.net/default.aspx/gdi32/BitBlt.html
var compatiblehDc = NativeMethods.CreateCompatibleDC(hDC);
var compatibleBitmap = NativeMethods.CreateCompatibleBitmap(hDC, bounds.Width, bounds.Height);
try
{
NativeMethods.SelectObject(compatiblehDc, compatibleBitmap);
// copy current screen to bitmap
// TODO: this is quite slow (80% of this method). Why?
NativeMethods.BitBlt(compatiblehDc, 0, 0, bounds.Width, bounds.Height, hDC, 0, 0, NativeMethods.SRCCOPY);
using (Graphics g = Graphics.FromHdc(compatiblehDc))
{
g.ExcludeClip(clientArea);
//cliping rect is not cliping rect but actual rectangle
_chrome.OnNonClientAreaPaint(new NonClientPaintEventArgs(
g,
bounds,
clipRegion,
IsMaximized,
IsActive
));
}
// copy current from bitmap to screen
NativeMethods.BitBlt(hDC, 0, 0, bounds.Width, bounds.Height, compatiblehDc, 0, 0, NativeMethods.SRCCOPY);
}
finally
{
NativeMethods.DeleteObject(compatibleBitmap);
NativeMethods.DeleteDC(compatiblehDc);
}
}
}
finally
{
NativeMethods.ReleaseDC(Handle, hDC);
}
}
