Question

我的文字在更改时重叠。

但这是时间文本，所以总是在变化

我已经尝试过

TranslateBlt（memhdc，TextBoxRect.left，TextBoxRect.top，TextBoxRect.right，TextBoxRect.bottom，hdc，TextBoxRect.right，TextBoxRect.bottom，RGB（0,0,0））;

案例WM_ERASEBKGND：返回true;

InvalidateRect（NULL，＆TextBoxRect，TRUE）;

这是我的代码。

HDC hdc = GetDC(NULL);
HDC memhdc;
HBITMAP bgbitmap, oldbitmap;

stringstream stream;
int cur = delay / 10;
stream << "Ms : " << msec;
wchar_t str[120];
mbstowcs_s(NULL, str, 120, stream.str().c_str(), 120);

memhdc = CreateCompatibleDC(hdc);
bgbitmap = CreateCompatibleBitmap(hdc, TextBoxRect.right, TextBoxRect.bottom);
oldbitmap = (HBITMAP) SelectObject(memhdc, bgbitmap);

BLENDFUNCTION bf;
bf.BlendOp = AC_SRC_OVER;
bf.BlendFlags = 0;
bf.SourceConstantAlpha = 255;
bf.AlphaFormat = 0;

AlphaBlend(memhdc, TextBoxRect.left, TextBoxRect.top, TextBoxRect.right, TextBoxRect.bottom, hdc, TextBoxRect.left, TextBoxRect.top, TextBoxRect.right, TextBoxRect.bottom, bf);
SetBkMode(memhdc, TRANSPARENT);
SetTextColor(memhdc, RGB(255, 0, 0));
DrawText(memhdc, str, -1, &TextBoxRect, DT_LEFT | DT_NOCLIP);

BitBlt(hdc, TextBoxRect.left, TextBoxRect.top, TextBoxRect.right, TextBoxRect.bottom, memhdc, TextBoxRect.left, TextBoxRect.top, SRCCOPY);

DeleteObject(SelectObject(memhdc,oldbitmap));
DeleteObject(bgbitmap);
DeleteDC(memhdc);
ReleaseDC(NULL, hdc);

Answer 1

我想您已经准备好进行透明的数字更改。

您可以尝试同时调用InvalidateRect和UpdateWindow来刷新局部区域，因为系统将窗口中的绘制操作视为低优先级操作，可以立即重新绘制与UpdateWindow。

您也可以尝试以下代码，如乔纳森·波特所说的

就像：

   AlphaBlend(memhdc, TextBoxRect.left, TextBoxRect.top, TextBoxRect.right,       TextBoxRect.bottom, hdc, TextBoxRect.left, TextBoxRect.top, TextBoxRect.right, TextBoxRect.bottom, bf);
   SetBkMode(hdc, TRANSPARENT);
   SetTextColor(hdc, RGB(255, 0, 0));       
   BitBlt(hdc, TextBoxRect.left, TextBoxRect.top, TextBoxRect.right, TextBoxRect.bottom, hdc, TextBoxRect.left, TextBoxRect.top, SRCCOPY);
   DrawText(hdc, str, -1, &TextBoxRect, DT_LEFT | DT_NOCLIP);

在AlphaBlend中使用双缓冲位图时的问题

1 个答案: