Sorry Manuel
Fwppc perhaps not support GDI
but you can found helps from this
http://www.pocketpcdn.com/forum/index.phpOr you can see here :
http://www.pocketpcdn.com/articles/tran ... tatic.htmlor here
http://www.codeproject.com/KB/mobile/tr ... trols.aspxFor WinCE 2.0 and later you can the TransparentImage() instead of BitBlt which takes a COLORREF as its last parameter that is used as a transparency color
Here's the function prototype for TransparentImage
BOOL TransparentImage(HDC hdcDest, LONG DstX, LONG DstY, LONG DstCx, LONG DstCy, HANDLE hSrc, LONG SrcX, LONG SrcY, LONG SrcCx, LONG SrcCy, COLORREF TransparentColor );
It may not do exactly what you want but it will give you a wider range to use as the transparent color
for sample I found How draw a circle in Transparency
/// This will hold the data regarding the Transparency
BLENDFUNCTION blendFunction;
blendFunction.BlendOp = (byte)0x00;
blendFunction.BlendFlags = (byte)0x00;
blendFunction.SourceConstantAlpha = 210;
blendFunction.AlphaFormat = (byte)0;
////////////////////////////////////////////////////////////////////////////////
/////////// Draw the transpernt image
if (0 == AlphaBlend(hdc, 0, BTStripY,DEVICEWIDTH,100,
hcompdc, 0, 0, 48,20, blendFunction));