最近公司有一要求，就是画一条曲线，效果是颜色从线中向两边淡出。找了些能实现渐变画图函数，它们基本上
上都是填充一个矩形或三角形，包括GDI+，结果都不是很满意。后来发现ExtCreatePen这个函数画大小1像素的虚线点线线头为方块等都好
，感觉可以实现，仅仅是感觉，思路是做一淡入淡出的位图，然后用这个函数将位图选入画笔。里面有要一个LOGBRUSH结构，
typedef struct tagLOGBRUSH {
UINT lbStyle;
COLORREF lbColor;
LONG lbHatch;
} LOGBRUSH, *PLOGBRUSH;
If lbStyle is BS_DIBPATTERN, the lbHatch member contains a handle to a packed DIB. To obtain this handle,
an application calls the GlobalAlloc function with GMEM_MOVEABLE (or LocalAlloc with LMEM_MOVEABLE) to
allocate a block of memory and then fills the memory with the packed DIB. A packed DIB consists of a BITMAPINFO
structure immediately followed by the array of bytes that define the pixels of the bitmap.
当lbStyle选为BS_DIBPATTERN,lbHatch就是DIB句柄。关键是我对DIB不是很了解，论坛中有贴如下:
CreateFile 打开文件
ReadFile 把指针移动到DIB数据部分（跳过文件头14个字节吧和信息头40个字节）
再memcpy到内存中，(分配空间时用句柄HANDLE hDIB)
有谁能具体结合英文注释给写一个获得DIB句柄的小例子？公司要求比较急！
LOGBRUSH logBrush;
logBrush.lbStyle = BS_HATCHED;
logBrush.lbColor = RGB(0, 192, 192);
logBrush.lbHatch = HS_CROSS;// Declare an uninitialized CBrush ...
CBrush brush;
// ... and initialize it with the LOGBRUSH.
brush.CreateBrushIndirect(&logBrush);// Select the brush (and perhaps a pen) into
// the device context.
CBrush* pOldBrush = (CBrush*)pDC->SelectObject(&brush);
CPen* pOldPen = (CPen*)pDC->SelectStockObject(BLACK_PEN);// Have fun!
pDC->Pie(CRect(100, 100, 300, 300), CPoint(0, 0), CPoint(50, 200));// Restore the original device context objects.
pDC->SelectObject(pOldBrush);
pDC->SelectObject(pOldPen);
你写的这个我知道怎么用。 If lbStyle is BS_DIBPATTERN, the lbHatch member contains a handle to a packed DIB. To obtain this handle,an application calls the GlobalAlloc function with GMEM_MOVEABLE (or LocalAlloc with LMEM_MOVEABLE) to allocate a block of memory and then fills the memory with the packed DIB. A packed DIB consists of a BITMAPINFO structure immediately followed by the array of bytes that define the pixels of the bitmap. 我想把这个logBrush的lbStyle值设为BS_DIBPATTERN，然后这个初始化一个Pen,再用这个Pen画线
HANDLE hFile = CreateFile(_T("1.bmp"),GENERIC_READ,FILE_SHARE_READ,NULL,OPEN_EXISTING,
NULL,NULL);
if(hFile == INVALID_HANDLE_VALUE )
{
MessageBox(_T("aa"));
return;
} DWORD dwFileSize,dwHighSize,dwBytesRead;
BITMAPFILEHEADER * pbmfh;
BOOL bSuccess;
dwFileSize = GetFileSize(hFile,&dwHighSize);
if(dwHighSize)
{
CloseHandle(hFile);
return;
}
pbmfh =(BITMAPFILEHEADER *) malloc(dwFileSize);
if(!pbmfh)
{
CloseHandle(hFile);
return ;
}
bSuccess = ReadFile(hFile,pbmfh,54,&dwBytesRead,NULL);
HGDIOBJ hmem = GlobalAlloc(GMEM_MOVEABLE,dwFileSize - 54);
memcpy(hmem,pbmfh,dwFileSize - 54); LOGBRUSH lb;
lb.lbStyle = BS_DIBPATTERNPT;
lb.lbColor =DIB_RGB_COLORS;
lb.lbHatch =(ULONG_PTR) hmem;
HPEN hPen1 = ExtCreatePen(PS_GEOMETRIC | PS_DASH ,20,&lb,0,NULL);
CClientDC dc(this);
HGDIOBJ hOldPen;
hOldPen = dc.SelectObject(hPen1);
dc.MoveTo(25,25);
dc.LineTo(100,100); CloseHandle(hFile);
free(pbmfh);结果是想用选入的位图画线