下面的代碼是發送端對游標（滑鼠）進行截圖，得到游標的位圖資料后經網路發送給接收端：
class CCursorMetadata
{
virtual bool InitMetadata(HCURSOR hCursor,unsigned short sBitCount);
HDC m_hdc_mem; //The compatible memory DC of desktop.
HBITMAP m_hBitmap;
LPBITMAPINFO m_lpBitmapInfo; //Pointer to the BITMAPINFO of the bitmap.
void* m_lpBitmapBits; //Pointer to the bitmap bits values.
}
bool CCursorMetadata::InitMetadata(HCURSOR hCursor,unsigned short sBitCount)
{
ICONINFO iconInfo;
if(!GetIconInfo(hCursor, &iconInfo)){
return false;
}
if(iconInfo.hbmMask==NULL){
return false;
}
bool isColorShape=(iconInfo.hbmColor!=NULL);
BITMAP bmMask;
if(!GetObject(iconInfo.hbmMask,sizeof(BITMAP),(void*)&bmMask)){
DeleteObject(iconInfo.hbmMask);
return false;
}
if(bmMask.bmPlanes!=1 || bmMask.bmBitsPixel!=1){
DeleteObject(iconInfo.hbmMask);
return false;
}
int iWidth=bmMask.bmWidth;
int iHeight=isColorShape?bmMask.bmHeight:bmMask.bmHeight/2;
//int widthBytes=bmMask.bmWidthBytes;
HDC hdcDesktop=GetDC(NULL);
m_hdc_mem=CreateCompatibleDC(hdcDesktop);
int cColor=(sBitCount<=8)?(1<<sBitCount):(0);
int iBmInfoSize=sizeof(BITMAPINFOHEADER) + cColor * sizeof(RGBQUAD);
m_lpBitmapInfo=(LPBITMAPINFO)new unsigned char[iBmInfoSize];
BITMAPINFOHEADER& bmiHeader=m_lpBitmapInfo->bmiHeader;
bmiHeader.biSize=sizeof(BITMAPINFOHEADER);
bmiHeader.biWidth=iWidth;
bmiHeader.biHeight=iHeight;
bmiHeader.biPlanes=1;
bmiHeader.biBitCount=sBitCount;
bmiHeader.biCompression=BI_RGB;
bmiHeader.biSizeImage=(((bmiHeader.biWidth *bmiHeader.biBitCount + 31) & ~31) >> 3) * bmiHeader.biHeight;
bmiHeader.biXPelsPerMeter=0;
bmiHeader.biYPelsPerMeter=0;
bmiHeader.biClrUsed=0;
bmiHeader.biClrImportant=0;
HBITMAP hBitmap=CreateCompatibleBitmap(hdcDesktop,1,1);
GetDIBits(hdcDesktop,hBitmap,0,0,NULL,m_lpBitmapInfo,DIB_RGB_COLORS);
DeleteObject(hBitmap);
m_hBitmap=CreateDIBSection(hdcDesktop,m_lpBitmapInfo,DIB_RGB_COLORS,&m_lpBitmapBits,NULL,0);
SelectObject(m_hdc_mem,m_hBitmap);
DeleteObject(iconInfo.hbmMask);
return (m_hBitmap!=NULL);
};
DrawIconEx(m_hdc_mem,0,0,hCursor,0,0,0,NULL,DI_IMAGE);
NetSend(m_lpBitmapBits);
當接收端接收到m_lpBitmapBits表示的位圖資料之后，怎樣顯示該游標的位圖呢？
如果使用DrawIconEx函式來繪制該游標的話，那怎么由位圖資料的byte得到它對應的HCURSOR呢？即DrawIconEx第二個引數。
uj5u.com熱心網友回復：
程式的意圖是想讓接收端能夠監視到發送端滑鼠的操作（移動，形狀發生了變化等），包括發送端使用自定義的滑鼠時也能監視得到，而不僅局限于系統自帶的滑鼠指標形狀。注意，接收端顯示該游標指標時不能使用StretchDIBits之類的函式。uj5u.com熱心網友回復：
hIconHandle to the icon or cursor to be drawn. This parameter can identify an animated cursor. The icon or cursor resource must have been previously loaded by using the LoadImage function.
LoadImage
The LoadImage function loads an icon, cursor, or bitmap.
HANDLE LoadImage(
HINSTANCE hinst, // handle of the instance containing the image
LPCTSTR lpszName, // name or identifier of image
UINT uType, // type of image
int cxDesired, // desired width
int cyDesired, // desired height
UINT fuLoad // load flags
);
Parameters
hinst
Handle to an instance of the module that contains the image to be loaded. To load an OEM image, set this parameter to zero.
lpszName
Handle to the image to load.
If the hinst parameter is non-NULL and the fuLoad parameter does not include LR_LOADFROMFILE, lpszName is a pointer to a null-terminated string that contains the name of the image resource in the hinst module.
If hinst is NULL and LR_LOADFROMFILE is not specified, the low-order word of this parameter must be the identifier of the OEM image to load. The OEM image identifiers are defined in WINUSER.H and have the following prefixes: Prefix Meaning
OBM_ OEM bitmaps
OIC_ OEM icons
OCR_ OEM cursors
If the fuLoad parameter includes the LR_LOADFROMFILE value, lpszName is the name of the file that contains the image.
uType
Specifies the type of image to be loaded. This parameter can be one of the following values: Value Meaning
IMAGE_BITMAP Loads a bitmap.
IMAGE_CURSOR Loads a cursor.
IMAGE_ICON Loads an icon.
cxDesired
Specifies the width, in pixels, of the icon or cursor. If this parameter is zero and the fuLoad parameter is LR_DEFAULTSIZE, the function uses the SM_CXICON or SM_CXCURSOR system metric value to set the width. If this parameter is zero and LR_DEFAULTSIZE is not used, the function uses the actual resource width.
cyDesired
Specifies the height, in pixels, of the icon or cursor. If this parameter is zero and the fuLoad parameter is LR_DEFAULTSIZE, the function uses the SM_CYICON or SM_CYCURSOR system metric value to set the height. If this parameter is zero and LR_DEFAULTSIZE is not used, the function uses the actual resource height.
fuLoad
Specifies a combination of the following values: Value Meaning
LR_DEFAULTCOLOR The default flag; it does nothing. All it means is "not LR_MONOCHROME".
LR_CREATEDIBSECTION When the uType parameter specifies IMAGE_BITMAP, causes the function to return a DIB section bitmap rather than a compatible bitmap. This flag is useful for loading a bitmap without mapping it to the colors of the display device.
LR_DEFAULTSIZE Uses the width or height specified by the system metric values for cursors or icons, if the cxDesired or cyDesired values are set to zero. If this flag is not specified and cxDesired and cyDesired are set to zero, the function uses the actual resource size. If the resource contains multiple images, the function uses the size of the first image.
LR_LOADFROMFILE Loads the image from the file specified by the lpszName parameter. If this flag is not specified, lpszName is the name of the resource.
LR_LOADMAP3DCOLORS Searches the color table for the image and replaces the following shades of gray with the corresponding 3D color:
Color Replaced with
Dk Gray,
RGB(128,128,128) COLOR_3DSHADOW
Gray,
RGB(192,192,192) COLOR_3DFACE
Lt Gray,
RGB(223,223,223) COLOR_3DLIGHT
LR_LOADTRANSPARENT Retrieves the color value of the first pixel in the image and replaces the corresponding entry in the color table with the default window color (COLOR_WINDOW). All pixels in the image that use that entry become the default window color. This value applies only to images that have corresponding color tables.
If fuLoad includes both the LR_LOADTRANSPARENT and LR_LOADMAP3DCOLORS values, LRLOADTRANSPARENT takes precedence. However, the color table entry is replaced with COLOR_3DFACE rather than COLOR_WINDOW.
LR_MONOCHROME Loads the image in black and white.
LR_SHARED Shares the image handle if the image is loaded multiple times. If LR_SHARED is not set, a second call to LoadImage for the same resource will load the image again and return a different handle.
Do not use LR_SHARED for images that have non-standard sizes, that may change after loading, or that are loaded from a file.
Windows 95 and Windows 98: The function finds the first image with the requested resource name in the cache, regardless of the size requested.
LR_VGACOLOR Uses true VGA colors.
Return Values
If the function succeeds, the return value is the handle of the newly loaded image.
If the function fails, the return value is NULL. To get extended error information, callGetLastError.
Remarks
When you are finished using the bitmap, cursor, or icon, you can release its associated memory by calling one of the functions in the following table.
Resource Release function
Bitmap DeleteObject
Cursor DestroyCursor
Icon DestroyIcon
The system automatically deletes these resources when the process that created them terminates, however, calling the appropriate function saves memory and decreases the size of the process's working set.
Windows CE: The cxDesired and cyDesired parameters must be zero for IMAGE_BITMAP.
Windows CE does not support stretching and shrinking of icons.
The fuLoad parameter must be zero (==LR_DEFAULTCOLOR).
If you are targeting a platform that does not support mouse cursors, you cannot specify the SM_CXCURSOR and SM_CYCURSOR values in the cxDesired and cyDesired parameters, and you cannot specify IMAGE_CURSOR for the uType parameter.
If you are targeting a platform that supports mouse cursors, you can specify SM_CXCURSOR and SM_CYCURSOR in the cxDesired and cyDesired parameters, and IMAGE_CURSOR in the uType parameter.
QuickInfo
Windows NT: Requires version 4.0 or later.
Windows: Requires Windows 95 or later.
Windows CE: Requires version 1.0 or later.
Header: Declared in winuser.h.
Import Library: Use user32.lib.
Unicode: Implemented as Unicode and ANSI versions on Windows NT.
See Also
Resources Overview, Resource Functions, CopyImage,GetSystemMetrics,LoadBitmap, LoadCursor, LoadIcon
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