20.VC(ui)-图片处理的一些函数

自己经常写的，写多了就慢慢总结下来，方便：

//---------------------------------------------------

// 函数介绍：把资源写入lpImage，支持BMP,PNG,JPG.

// 输入参数:

// 输出参数:

// 返回值:

//---------------------------------------------------

BOOL CImageManager::LoadResImage(UINT nResID,
LPCTSTR lpType,
Bitmap *&lpImage,
HINSTANCE hInstance)
{
lpImage  = NULL;

hInstance = (NULL == hInstance) ? ::AfxGetResourceHandle() : hInstance;
// If bmp,use system load.
if (RT_BITMAP == lpType)
{
HBITMAP hBmp = ::LoadBitmap(hInstance, MAKEINTRESOURCE(nResID));
lpImage = Bitmap::FromHBITMAP(hBmp, 0);
::DeleteObject(hBmp);

if (!lpImage)
{
TRACE("lpImage is NULL\n");
return FALSE;
}
else
{
if (Gdiplus::Ok != lpImage->GetLastStatus())
{
TRACE("lpImage is error\n");
return FALSE;
}
else
{
return TRUE;
}
}
}

// User-Defined

HRSRC hRsrc = ::FindResource(hInstance, MAKEINTRESOURCE(nResID), lpType);
if (!hRsrc)
{
TRACE("hRscs is NULL\n");
return FALSE;
}

// Load resource into memory ---------------------------------
DWORD len = ::SizeofResource(hInstance, hRsrc);

BYTE *lpRsrc = (BYTE*)::LoadResource(hInstance, hRsrc);
if (!lpRsrc)
{
TRACE("lpRsrc is NULL\n");
return FALSE;
}

// Allocate global memory on which to create stream ----------
HGLOBAL hMem = ::GlobalAlloc(GMEM_FIXED, len);

BYTE *pMem = (BYTE*)::GlobalLock(hMem);
memcpy(pMem, lpRsrc, len);

IStream *pStream = NULL;
// You can query MSDN,why I use TRUE, -- hgy notes.
HRESULT ht = ::CreateStreamOnHGlobal(hMem, TRUE, &pStream);
if (S_OK != ht)
{
TRACE("ht is error\n");
return FALSE;
}

// Load from stream -------------------------------------------
lpImage = Gdiplus::Bitmap::FromStream(pStream);

// free/release stuff -----------------------------------------
::GlobalUnlock(hMem);
pStream->Release();
::FreeResource(lpRsrc);

if (!lpImage)
{
TRACE("lpImage is NULL\n");
return FALSE;
}
else
{
if (Gdiplus::Ok != lpImage->GetLastStatus())
{
TRACE("lpImage is error\n");
return FALSE;
}
else
{
return TRUE;
}
}
}

//---------------------------------------------------

// 函数介绍：抓取当前窗口的图片

// 输入参数: 传NULL抓的是这个窗口下面的屏幕背景.(如果是透明的，就是透明的背景)

// 输出参数:

// 返回值:

//---------------------------------------------------

HBITMAP CImageManager::GetWindowBitmap(HWND hWnd, LPRECT lpRect)
{
if (!lpRect)
{
return NULL;
}

HDC hDC = NULL;

if (NULL == hWnd)
{
hDC = ::GetDC(HWND_DESKTOP);
}
else
{
hDC = ::GetWindowDC(hWnd);
}

if (NULL == hDC)
{
return NULL;
}

HDC hMemDC = ::CreateCompatibleDC(hDC);
HBITMAP hBitmap = ::CreateCompatibleBitmap(hDC, lpRect->right-lpRect->left,
lpRect->bottom-lpRect->top);

if (NULL == hBitmap)
{
return NULL;
}

HBITMAP hOldBitmap = (HBITMAP)::SelectObject(hMemDC, hBitmap);
::BitBlt(hMemDC, 0, 0, lpRect->right-lpRect->left,
lpRect->bottom-lpRect->top, hDC, lpRect->left,
lpRect->top, SRCCOPY);

::SelectObject(hMemDC, hOldBitmap);
::DeleteDC(hMemDC);
::ReleaseDC(hWnd, hDC);

return hBitmap;
}

//---------------------------------------------------

// 函数介绍：把HBITMAP保存成文件

// 输入参数:

// 输出参数:

// 返回值:

//---------------------------------------------------

BOOL CImageManager::SaveBitmapToFile(HBITMAP hBitmap,
CString FileName)
{
if (hBitmap==NULL
|| FileName.IsEmpty())
{
return false;
}
// -----------------------------------------------------
//DIB文件有四个主要部分：
//	文件表头	　
//	信息表头	　
//	RGB色彩对照表（不一定有）　
//	位图图素位
//Windows中DIB的扩展版本:
// 以BITMAPFILEHEADER结构开始，接着是BITMAPINFOHEADER结构
//
// -----------------------------------------------------

//指向位图信息头结构
LPBITMAPINFOHEADER lpbi;
//定义文件，分配内存句柄，调色板句柄
HANDLE fh, hDib, hPal,hOldPal=NULL;

//计算位图文件每个像素所占字节数
HDC hDC = CreateDC(TEXT("DISPLAY"), NULL, NULL, NULL);
//当前分辨率下每象素所占字节数
int iBits = GetDeviceCaps(hDC, BITSPIXEL) * GetDeviceCaps(hDC, PLANES);
DeleteDC(hDC);

WORD wBitCount;
if (iBits <= 1)
{
wBitCount = 1;
}
else if (iBits <= 4)
{
wBitCount = 4;
}
else if (iBits <= 8)
{
wBitCount = 8;
}
else
{
wBitCount = 24;
}

//定义调色板大小， 位图中像素字节大小 ，位图文件大小 ， 写入文件字节数
DWORD dwPaletteSize=0, dwBmBitsSize=0, dwDIBSize=0, dwWritten=0;

//位图属性结构
BITMAP Bitmap;
::GetObject(hBitmap, sizeof(Bitmap), (LPSTR)&Bitmap);

//位图信息头结构
/* --------------------------------------------------------------
struct tagBITMAPINFOHEADER{
DWORD      biSize;//40
LONG       biWidth;//BITMAP::bmWidth
LONG       biHeight;//BITMAP::bmHeight
WORD       biPlanes;//1
WORD       biBitCount;
DWORD      biCompression;
DWORD      biSizeImage;
LONG       biXPelsPerMeter;
LONG       biYPelsPerMeter;
DWORD      biClrUsed;
DWORD      biClrImportant;
} BITMAPINFOHEADER
----------------------------------------------------------------*/
BITMAPINFOHEADER bi;
bi.biSize          = sizeof(BITMAPINFOHEADER);
bi.biWidth         = Bitmap.bmWidth;
bi.biHeight        = Bitmap.bmHeight;
bi.biPlanes        = 1;//
bi.biBitCount      = wBitCount;
bi.biCompression   = BI_RGB;
bi.biSizeImage     = 0;
bi.biXPelsPerMeter = 0;
bi.biYPelsPerMeter = 0;
bi.biClrImportant  = 0;
bi.biClrUsed       = 0;

// -------------------------------------------------------
// 以字节为单位的每行长度始终是4的倍数。行的长度可以计算为：
// RowLength = 4 * ((bmch.bcWidth * bmch.bcBitCount + 31) / 32) ;
// 或者在C内用更有效的方法：
// RowLength = ((bmch.bcWidth * bmch.bcBitCount + 31) & ~31) >> 3 ;
// -------------------------------------------------------
//图素数据的总字节数等于RowLength和Bitmap.bmHeight的乘积。
dwBmBitsSize = ((Bitmap.bmWidth * wBitCount + 31) / 32) * 4 * Bitmap.bmHeight;

//为位图内容分配内存
hDib = GlobalAlloc(GHND,dwBmBitsSize + dwPaletteSize + sizeof(BITMAPINFOHEADER));
lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDib);
*lpbi = bi;

// 处理调色板
hPal = GetStockObject(DEFAULT_PALETTE);
if (hPal)
{
hDC = ::GetDC(NULL);
hOldPal = ::SelectPalette(hDC, (HPALETTE)hPal, FALSE);
RealizePalette(hDC);
}

// 获取该调色板下新的像素值
GetDIBits(hDC, hBitmap, 0, (UINT) Bitmap.bmHeight, (LPSTR)lpbi + sizeof(BITMAPINFOHEADER)
+dwPaletteSize, (BITMAPINFO *)lpbi, DIB_RGB_COLORS);

// 恢复调色板
if (hOldPal)
{
::SelectPalette(hDC, (HPALETTE)hOldPal, TRUE);
RealizePalette(hDC);
::ReleaseDC(NULL, hDC);
}

// 创建位图文件
fh = CreateFile(FileName, GENERIC_WRITE,0, NULL, CREATE_ALWAYS,
FILE_ATTRIBUTE_NORMAL | FILE_FLAG_SEQUENTIAL_SCAN, NULL);

if (fh == INVALID_HANDLE_VALUE)  return FALSE;

//位图文件头结构
/* --------------------------------------------------------------
struct tagBITMAPFILEHEADER {
WORD    bfType;// "BM" 或 0x4D42
DWORD   bfSize;//整个文件的大小.
WORD    bfReserved1;//0
WORD    bfReserved2;//0
DWORD   bfOffBits;//指出了文件中图素位开始位置的字节偏移量,此数值来自DIB信息表头中的信息，为了使用的方便提供在这里
//这样，我们可以很快定位到图形数据的起始位.
} BITMAPFILEHEADER
--------------------------------------------------------------*/
BITMAPFILEHEADER bmfHdr;

// 设置位图文件头
bmfHdr.bfType = 0x4D42; // "BM"
dwDIBSize = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) + dwPaletteSize + dwBmBitsSize;
bmfHdr.bfSize = dwDIBSize;
bmfHdr.bfReserved1 = 0;
bmfHdr.bfReserved2 = 0;
bmfHdr.bfOffBits = (DWORD)sizeof(BITMAPFILEHEADER) + (DWORD)sizeof(BITMAPINFOHEADER) + dwPaletteSize;
// 写入位图文件头
WriteFile(fh, (LPSTR)&bmfHdr, sizeof(BITMAPFILEHEADER), &dwWritten, NULL);
// 写入位图文件其余内容
WriteFile(fh, (LPSTR)lpbi, dwDIBSize, &dwWritten, NULL);
//清除
GlobalUnlock(hDib);
GlobalFree(hDib);
CloseHandle(fh);

return TRUE;

}

//---------------------------------------------------

// 函数介绍：改变HBITMAP中所有的A值

// 输入参数:

// 输出参数:

// 返回值:

//---------------------------------------------------

void CImageManager::ChangeHBitmapAlpha(HBITMAP hBitmap, int alpha)
{
DWORD dwSize = ::GetBitmapBits(hBitmap, 0, NULL);
char *lpBuffer = new char[dwSize];
::GetBitmapBits(hBitmap,dwSize,lpBuffer);

for(int i = 0; i+3<dwSize; i+=4)
{
lpBuffer[i+3] = alpha;
//lpBuffer[i+0] = 0;//B
//lpBuffer[i+1] = 0;//G
//lpBuffer[i+2] = 0;//R
}

::SetBitmapBits(hBitmap,dwSize, lpBuffer);
delete[] lpBuffer;
}