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1楼
巨大八爪鱼
2016-2-6 10:27
case WM_DRAWITEM:
{
LPDRAWITEMSTRUCT lpDis = (LPDRAWITEMSTRUCT)lParam;
if (lpDis->CtlID == IDC_STATIC1)
{
HDC hdcMem = CreateCompatibleDC(lpDis->hDC);
HBITMAP hbmp = CreateCompatibleBitmap(lpDis->hDC, lpDis->rcItem.right - lpDis->rcItem.left, lpDis->rcItem.bottom - lpDis->rcItem.top);
SelectObject(hdcMem, hbmp);
HPEN hpen = CreatePen(PS_SOLID, 1, COL_848400);
SelectObject(hdcMem, hpen);
MoveToEx(hdcMem, 10, 10, NULL);
LineTo(hdcMem, 120, 120);
BitBlt(lpDis->hDC, lpDis->rcItem.left, lpDis->rcItem.top, lpDis->rcItem.right - lpDis->rcItem.left, lpDis->rcItem.bottom - lpDis->rcItem.top, hdcMem, 0, 0, SRCCOPY);
DeleteDC(hdcMem);
DeleteObject(hbmp);
DeleteObject(hpen);
}
}
break;
}
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2楼
巨大八爪鱼
2016-2-6 18:03
創建了compatible DC後一定要創建一個compatible bitmap並選定，否則這個hdc由於沒有對應目標設備而無法輸出繪製的圖形。
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3楼
巨大八爪鱼
2016-2-6 18:05
此外，默認創建的bitmap中所有像素都是黑色，因為此時內存中全是0。
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4楼
巨大八爪鱼
2016-2-6 20:47
INT_PTR CALLBACK DlgProc(HWND hDlg, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
switch (uMsg)
{
case WM_INITDIALOG:
ShowCursor(TRUE);
break;
case WM_COMMAND:
{
int wmId = LOWORD(wParam);
switch (wmId)
{
case IDCANCEL:
case IDOK:
ShowCursor(FALSE);
EndDialog(hDlg, wmId);
break;
}
}
break;
case WM_DRAWITEM:
{
LPDRAWITEMSTRUCT lpDis = (LPDRAWITEMSTRUCT)lParam;
if (lpDis->CtlID == IDC_STATIC1)
{
HDC hdcMem = CreateCompatibleDC(lpDis->hDC);
HBITMAP hbmp = CreateCompatibleBitmap(lpDis->hDC, lpDis->rcItem.right - lpDis->rcItem.left, lpDis->rcItem.bottom - lpDis->rcItem.top);
SelectObject(hdcMem, hbmp);
HPEN hpen = CreatePen(PS_SOLID, 1, COL_848400);
SelectObject(hdcMem, hpen);
MoveToEx(hdcMem, 10, 10, NULL);
LineTo(hdcMem, 120, 120);
BitBlt(lpDis->hDC, lpDis->rcItem.left, lpDis->rcItem.top, lpDis->rcItem.right - lpDis->rcItem.left, lpDis->rcItem.bottom - lpDis->rcItem.top, hdcMem, 0, 0, SRCCOPY);
DeleteDC(hdcMem);
DeleteObject(hbmp);
DeleteObject(hpen);
}
}
break;
}
return FALSE;
}
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