檢查裝置支援的像素格式

DescribePixelFormat 函式會取得裝置內容的圖元格式數據。 它也會傳回整數，這個整數是裝置上下文的最大像素格式索引。 下列程式碼範例示範如何使用該結果逐步檢視並檢查裝置支援的圖元格式：

// local variables  
int                      iMax ; 
PIXELFORMATDESCRIPTOR    pfd; 
int                      iPixelFormat ; 
 
// initialize a pixel format index variable  
iPixelFormat = 1; 
 
// keep obtaining and examining pixel format data...  
do { 
    // try to obtain some pixel format data  
    iMax = DescribePixelFormat(hdc, iPixelFormat, sizeof(pfd), &pfd); 
 
    // if there was some problem with that...   
    if (iMax == 0) 
     
        // return indicating failure  
        return(FALSE); 
     
    // we have successfully obtained pixel format data  
 
    // let's examine the pixel format data...  
    myPixelFormatExaminer (&pfd); 
    }  
 
// ...until we've looked at all the device context's pixel formats  
while (++iPixelFormat <= iMax);