class CBitmap : public CGdiObject
{
DECLARE_DYNAMIC(CBitmap)
public:
static CBitmap* PASCAL FromHandle(HBITMAP hBitmap);
// Constructors
CBitmap();
BOOL LoadBitmap(LPCTSTR lpszResourceName);
BOOL LoadBitmap(UINT nIDResource);
BOOL LoadOEMBitmap(UINT nIDBitmap); // for OBM_/OCR_/OIC_
#ifndef _AFX_NO_AFXCMN_SUPPORT
BOOL LoadMappedBitmap(UINT nIDBitmap, UINT nFlags = 0,
LPCOLORMAP lpColorMap = NULL, int nMapSize = 0);
#endif
BOOL CreateBitmap(int nWidth, int nHeight, UINT nPlanes, UINT nBitcount,
const void* lpBits);
BOOL CreateBitmapIndirect(LPBITMAP lpBitmap);
BOOL CreateCompatibleBitmap(CDC* pDC, int nWidth, int nHeight);
BOOL CreateDiscardableBitmap(CDC* pDC, int nWidth, int nHeight);
// Attributes
operator HBITMAP() const;
int GetBitmap(BITMAP* pBitMap);
// Operations
DWORD SetBitmapBits(DWORD dwCount, const void* lpBits);
DWORD GetBitmapBits(DWORD dwCount, LPVOID lpBits) const;
CSize SetBitmapDimension(int nWidth, int nHeight);
CSize GetBitmapDimension() const;
// Implementation
public:
virtual ~CBitmap();
#ifdef _DEBUG
virtual void Dump(CDumpContext& dc) const;
#endif
};
父
CGdiObject
class CGdiObject : public CObject
{
DECLARE_DYNCREATE(CGdiObject)
public:
// Attributes
HGDIOBJ m_hObject; // must be first data member
operator HGDIOBJ() const;
HGDIOBJ GetSafeHandle() const;
static CGdiObject* PASCAL FromHandle(HGDIOBJ hObject);
static void PASCAL DeleteTempMap();
BOOL Attach(HGDIOBJ hObject);
HGDIOBJ Detach();
// Constructors
CGdiObject(); // must Create a derived class object
BOOL DeleteObject();
// Operations
#pragma push_macro("GetObject")
#undef GetObject
int _AFX_FUNCNAME(GetObject)(int nCount, LPVOID lpObject) const;
int GetObject(int nCount, LPVOID lpObject) const;
#pragma pop_macro("GetObject")
UINT GetObjectType() const;
BOOL CreateStockObject(int nIndex);
BOOL UnrealizeObject();
BOOL operator==(const CGdiObject& obj) const;
BOOL operator!=(const CGdiObject& obj) const;
// Implementation
public:
virtual ~CGdiObject();
#ifdef _DEBUG
virtual void Dump(CDumpContext& dc) const;
virtual void AssertValid() const;
#endif
};
1 裝載已導入工程的位圖資源
// 裝載位圖
CBitmap bmp;
bmp.LoadBitmap(IDB_BITMAP);
2 裝載位圖檔案
為了能讓CBitmap能夠裝載位圖檔案,必須調用API函數LoadImage
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
);
裝載: Example 1:
HBITMAP hBmp = (HBITMAP)LoadImage(NULL,
m_fileName,
IMAGE_BITMAP,
0, 0,
LR_LOADFROMFILE | LR_DEFAULTCOLOR | LR_DEFAULTSIZE);
Example 2:
HBITMAP hBmp = (HBITMAP)::LoadImage(AfxGetInstanceHandle(),
"BG.bmp",
IMAGE_BITMAP,
0,0,
LR_LOADFROMFILE);
将裝載後得到的HBITMAP資源句柄 與 CBitmap 對象 相連
if (hBmp != NULL) {
CBitmap *pBmp = CBitmap::FromHandle(hBmp);
}
或
CBitmap bmp;
if (hBmp != NULL) {
bmp.DeleteObject();
bmp.Attach(hBmp);
}
3 顯示位圖
CBitmap bmp;
bmp.LoadBitmap(IDB_BITMAP1);
BITMAP bm;
bmp.GetBitmap(&bm);
CDC dc;
dc.CreateCompatibleDC(pDC);
CBitmap*pOldBmp=(CBitmap *)dc.SelectObject(&bmp);
pDC->BitBlt(0,0,bm.bmWidth,bm.bmHeight,&dc,0,0,SRCCOPY);
pDC->SelectObject(pOldBmp);
bmp.DeleteObject();
bmp.LoadBitmap(IDB_BITMAP2);
4 删除資源
CBitmap bmp;
bmp.LoadBitmap(IDB_BITMAP);
CBitmap *pOld=pDC->SelectObject(&bmp);
// 此時位圖對象還在pDC中,是以不能馬上删除
// 而是先将位圖從DC中選出 然後再删除
pDC->SelectObject(pOld);
bmp.DeleteObject();
5 CBitmap 析構
當CBitmap作為局部變量 在其退出作用範圍後,會發生析構,這時候CBitmap會将其對應的位圖資源(hBitmap )釋放掉。
若想繼續使用該位圖資源hBitmap,則在退出作用範圍前,應将位圖資源hBitmap和CBitmap對象通過Detach()函數進行分離
HBITMAP CMyClass::Load()
{
CBitmap bmp;
bmp.LoadBitmap(IDB_BITMAP);
// 通過Detach 将資源與對象分離,這樣bmp析構後,資源仍存在
// 否則 ,bmp析構時,會将位圖資源一起析構掉,這樣出了局部範圍外,就不可再使用這個位圖資源了
return bmp.Detach();
}
6 在僅獲得HBITMAP資源句柄情況下,如何獲得這個資源的BITMAP資訊
BITMAP bm;
GetObject(hBitmap,sizeof(BITMAP),&bm);
7 在記憶體中開辟資源空間 将原圖儲存到記憶體中
//-------------------在記憶體中建立區域以存放所得位圖-------------------
// hBitmapSrc 為 CBitmap中儲存的矩形原圖資源句柄
// hDC 句柄
// 在記憶體中開辟位圖資源,用以儲存原圖
HBITMAP CopyHBitmap(HBITMAP hBitmapSrc,HDC hDC)
{
BITMAP bm;
HBITMAP hBitmapDst;
HDC hdcSrc,hdcDst;
GetObject(hBitmapSrc,sizeof(BITMAP),&bm);
hBitmapDst=CreateCompatibleBitmap(hDC,bm.bmWidth,bm.bmHeight);
hdcSrc=CreateCompatibleDC(hDC);
hdcDst=CreateCompatibleDC(hDC);
SelectObject(hdcSrc,hBitmapSrc);
SelectObject(hdcDst,hBitmapDst);
BitBlt(hdcDst,0,0,bm.bmWidth,bm.bmHeight,hdcSrc,0,0,SRCCOPY);
DeleteDC(hdcSrc);
DeleteDC(hdcDst);
return hBitmapDst;
}
轉自:http://www.cnblogs.com/lujin49/p/4960999.html