为什么这样不行啊?内存dc的问题.

[lsaturn]

HWND hwndStatic = ::GetDlgItem(m_hWnd, IDC_JPEGCANVAS);
HDC hWindowDC = ::GetWindowDC(hwndStatic);
HDC hWinMemDC = ::CreateCompatibleDC(hWindowDC);
RECT rectStatic = { 0 };
::GetClientRect(hwndStatic, &rectStatic);

::TextOut(hWinMemDC, 0, 0, "ab123456", 8);
BitBlt(hWindowDC, 0, 0, rectStatic.right - rectStatic.left,
rectStatic.bottom - rectStatic.top, hWinMemDC, 0, 0, SRCCOPY);

::DeleteDC(hWinMemDC);
::ReleaseDC(hwndStatic, hWindowDC);

上面这么一个简单的语句,可是就是没有办法在hWindowDC上面绘制"ab123456"这句话
但是::TextOut(hWindowDC, 0, 0, "ab123456", 8);是可以成功输出的.

不知道是我脑袋昏了还是什么,这个代码应该是可以的啊.

[bobob]

没有给内存dc创建兼容bitmap

[pomelowu]

HWND hwndStatic = ::GetDlgItem(m_hWnd, IDC_JPEGCANVAS);
HDC hWindowDC = ::GetWindowDC(hwndStatic);
HDC hWinMemDC = ::CreateCompatibleDC(hWindowDC);
HBITMAP hMemBitmap = ::CreateCompatibleBitmap(hWindowDC, 1024, 768);
HBITMAP hOldBitmap = ::SelectObject(hWinMemDC, hMemBitmap);

然后再画

[lanstar200]

HWND hwndStatic = ::GetDlgItem(m_hWnd, IDC_JPEGCANVAS);
HDC hWindowDC = ::GetWindowDC(hwndStatic);
HDC hWinMemDC = ::CreateCompatibleDC(hWindowDC);
RECT rectStatic = { 0 };
::GetClientRect(hwndStatic, &rectStatic);

HBITMAP hBmp = ::CreateCompatibleBitmap(hWindowDC , 100,100);
::SelectObject(hWinMemDC , hBmp);

::TextOut(hWinMemDC, 0, 0, "ab123456", 8);
BitBlt(hWindowDC, 0, 0, rectStatic.right - rectStatic.left,
rectStatic.bottom - rectStatic.top, hWinMemDC, 0, 0, SRCCOPY);

::DeleteDC(hWinMemDC);

::DeleteObject(hBmp);

::ReleaseDC(hwndStatic, hWindowDC);

[pomelowu]

完了记得把内存bitmap用SelectObject选出，并DeleteObject

[pomelowu]

汗~~~大家速度都快~~~

[bobob]

HWND hwndStatic = ::GetDlgItem(m_hWnd, IDC_JPEGCANVAS);
HDC hWindowDC = ::GetWindowDC(hwndStatic);
HDC hWinMemDC = ::CreateCompatibleDC(hWindowDC);
RECT rectStatic = { 0 };


==========================================================>>
HWND hwndStatic = ::GetDlgItem(m_hWnd, IDC_JPEGCANVAS);
HDC hWindowDC = ::GetWindowDC(hwndStatic);
HDC hWinMemDC = ::CreateCompatibleDC(hWindowDC);
HBITMAP hBitmap = CreateCompatibleBitmap(hWinMemDC,W,H));
HBITMAP hOldBitmap = (HBITMAP)SelectObject(hWinMemDC,hBitmap);
RECT rectStatic = { 0 };

[lsaturn]

谢谢谢谢
真的是昏了,忘了这么一茬了.