求教,妖哥大大,关于HDC句柄
我想从IMage的窗口句柄,用api GetDC,得到IMage的bitmap的HDC句柄,失败了,
void __fastcall TForm2::Button1Click(TObject *Sender)
{
TJPEGImage *jpg=new TJPEGImage();
TMemoryStream *stream=new TMemoryStream();
Graphics::TBitmap *BrushBmp = new Graphics::TBitmap;
BrushBmp->SetSize(352,480);
HDC hdc=GetWindowDC(BrushBmp->Handle) ;
//BrushBmp->Handle ;
stream->LoadFromFile("d:\\555.jpg") ;
stream->Seek(0,0);
jpg->LoadFromStream(stream);
Image1->Picture ->Bitmap ->Assign(jpg);
Image1->Picture ->Bitmap ->SaveToFile("d:\\124.bmp");
HANDLE h=Image1->Picture ->Bitmap ->Handle ;
HDC hdci=GetDC(h) ;
::StretchBlt(hdc,0,0,352,480,hdci,0,0,720,480,PATCOPY);
BrushBmp->SaveToFile("d:\\ok.bmp");
//jpg->
delete stream;
delete jpg;
delete BrushBmp;
}
主要目的是想用stretchBlt这个api进行bmp图片的缩放效果,但是调试发现,
取到的两个hdc,都是NULL,请教妖哥,我这样写为什么得不到正确的hdc
[解决办法]
Image->Canvas->Handle 就是HDC对象
