StretchBlt不支持对内存HDC的操作么 怎么实现不了，GetDeviceCaps怎么检测，是这样么？

[北漂17载]

StretchBlt不支持对内存HDC的操作么 怎么实现不了，GetDeviceCaps怎么检测，是这样么？
代码：
HDC htempDC;
htempDC=CreateCompatibleDC(memoryDC);
SetMapMode(htempDC,GetMapMode(memoryDC));
BitBlt(htempDC,0,0,bm.bmWidth,bm.bmHeight,htempDC,0,0,SRCCOPY);
int result;
result=GetDeviceCaps(memoryDC,RASTERCAPS);
if((RC_STRETCHBLT|result)>0)
{
MessageBox(hWnd,"Support the stretchbilet ","eee",MB_OK);
}//bm.bmWidth
StretchBlt(memoryDC,0,0,bm.bmWidth ,bm.bmHeight,htempDC,-bm.bmWidth,0,
bm.bmWidth,bm.bmHeight,SRCCOPY);
//BitBlt(memoryDC,0,0,bm.bmWidth,bm.bmHeight,hdc,0,0,SRCCOPY);
BitBlt(hdc,0,0,bm.bmWidth,bm.bmHeight,memoryDC,0,0,SRCCOPY);
if(GetLastError()!=0)
{
MessageBox(hWnd,"eeror vertical ","eee",MB_OK);
}
DeleteObject(htempDC);
其中：
HBITMAP hbmp;
BITMAP bm;
HDC memoryDC;
在sdk下

[cngdzhang]

给个例子,你看一下:
应该可以的,

函数 : DrawDIBSection（绘制DIBSection)
// hDC - 设备句柄
// hBitmap - DIB Section句柄
// xDest - 显示位图目标矩形的左上角X坐标
// yDest - 显示位图目标矩形的左上角Y坐标
void DrawDIBSection( HDC hDC, HBITMAP hBitmap, int xDest, int yDest )
{
HPALETTE hPal;

HDC hDCMem = ::CreateCompatibleDC( hDC );

// Create a logical palette for the bitmap
DIBSECTION ds;
BITMAPINFOHEADER &bmInfo = ds.dsBmih;
if( ::GetObject(hBitmap, sizeof(ds), &ds ) == 0 )
return; // Not a DIB Section

HGDIOBJ hBmpOld = ::SelectObject(hDCMem, hBitmap);

int nColors = bmInfo.biClrUsed ? bmInfo.biClrUsed : 1 << ds.dsBm.bmBitsPixel;

if( ::GetDeviceCaps(hDC, RASTERCAPS) & RC_PALETTE )
{
// Create a halftone palette if colors > 256.
if( nColors > 256 )
hPal = ::CreateHalftonePalette(hDC);
else
{
// Create the palette
RGBQUAD *pRGB = new RGBQUAD[nColors];

::GetDIBColorTable( hDCMem, 0, nColors, pRGB );

UINT nSize = sizeof(LOGPALETTE) + (sizeof(PALETTEENTRY) * nColors);
LOGPALETTE *pLP = (LOGPALETTE *) new BYTE[nSize];

pLP->palVersion = 0x300;
pLP->palNumEntries = nColors;

for( int i=0; i < nColors; i++)
{
pLP->palPalEntry[i].peRed = pRGB[i].rgbRed;
pLP->palPalEntry[i].peGreen = pRGB[i].rgbGreen;
pLP->palPalEntry[i].peBlue = pRGB[i].rgbBlue;
pLP->palPalEntry[i].peFlags = 0;
}

hPal = ::CreatePalette( pLP );

delete[] pLP;
delete[] pRGB;
}

HPALETTE hPalOld = ::SelectPalette(hDC,hPal,FALSE);
::RealizePalette(hDC);
BitBlt(hDC,xDest,yDest,bmInfo.biWidth,bmInfo.biHeight,hDCMem,0,0,SRCCOPY);

::SelectPalette(hDC,hPalOld,FALSE);
// delete GDI objects
::DeleteObject(hPal);
}
else
BitBlt(hDC,xDest,yDest,bmInfo.biWidth,bmInfo.biHeight,hDCMem,0,0,SRCCOPY);

::SelectObject(hDCMem, hBmpOld);
::DeleteDC(hDCMem);
}

[北漂17载]

我copy的代码有问题，关键的所在是两个 内存中的 HDC htempDC;HDC memoryDC; 在都CreateCompatibleDC（） 后彼此间能否 进行 biltblt 和 StretchBlt 进行内容从一个中往另一个中操作 我的试验是不行，我觉得没有道理。
谢谢：cngdzhang() 我会研究一下 调色板的问题