修正主窗口使用png背景时，插件项目自绘使用GDI绘制的文本变成透明的问题

zhongyang219 · Jan 14, 2025 · 4ef0022 · 4ef0022
1 parent 0c5e86e
commit 4ef0022
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Showing 3 changed files with 75 additions and 2 deletions.
diff --git a/TrafficMonitor/DrawCommon.cpp b/TrafficMonitor/DrawCommon.cpp
@@ -298,3 +298,57 @@ void DrawCommonHelper::ImageDrawAreaConvert(CSize image_size, CPoint& start_poin
         }
     }
 }
+
+void DrawCommonHelper::FixBitmapTextAlpha(HBITMAP hBitmap, BYTE alpha, const std::vector<CRect>& rects)
+{
+    if (rects.empty())
+        return;
+    BITMAP bm;
+    GetObject(hBitmap, sizeof(BITMAP), &bm);
+
+    int width = bm.bmWidth;
+    int height = bm.bmHeight;
+
+    // 获取位图的像素数据
+    BITMAPINFO bmpInfo = { 0 };
+    bmpInfo.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
+    bmpInfo.bmiHeader.biWidth = width;
+    bmpInfo.bmiHeader.biHeight = -height; // top-down DIB
+    bmpInfo.bmiHeader.biPlanes = 1;
+    bmpInfo.bmiHeader.biBitCount = 32;
+    bmpInfo.bmiHeader.biCompression = BI_RGB;
+
+    HDC hdc = CreateCompatibleDC(NULL);
+    SelectObject(hdc, hBitmap);
+
+    // 分配内存存储位图像素
+    RGBQUAD* pPixels = new RGBQUAD[width * height];
+    GetDIBits(hdc, hBitmap, 0, height, pPixels, &bmpInfo, DIB_RGB_COLORS);
+
+    // 遍历所有矩形区域
+    for (const auto& rect : rects)
+    {
+        int startX = max(0, rect.left);
+        int startY = max(0, rect.top);
+        int endX = min(width, rect.right);
+        int endY = min(height, rect.bottom);
+
+        // 遍历当前矩形内的像素
+        for (int y = startY; y < endY; ++y)
+        {
+            for (int x = startX; x < endX; ++x)
+            {
+                int index = y * width + x;
+                //如果检测到alpha值为0，则可能是被错误地设置成透明的文本部分，将其修正为正确的alpha值
+                if (pPixels[index].rgbReserved == 0)
+                    pPixels[index].rgbReserved = alpha; // 设置Alpha通道
+            }
+        }
+    }
+
+    // 将修改后的像素数据写回位图
+    SetDIBits(hdc, hBitmap, 0, height, pPixels, &bmpInfo, DIB_RGB_COLORS);
+
+    delete[] pPixels;
+    DeleteDC(hdc);
+}
diff --git a/TrafficMonitor/DrawCommon.h b/TrafficMonitor/DrawCommon.h
@@ -111,4 +111,7 @@ namespace DrawCommonHelper
     //stretch_mode[int]：拉伸模式
     void ImageDrawAreaConvert(CSize image_size, CPoint& start_point, CSize& size, IDrawCommon::StretchMode stretch_mode);
 
+    //修正位图中文本部分的Alpha通道
+    //使用了UpdateLayeredWindow后，使用GDI绘制的文本也会变得透明，此函数会遍历bitmap中alpha值为0的部分，将其修正为正确的alpha值
+    void FixBitmapTextAlpha(HBITMAP hBitmap, BYTE alpha, const std::vector<CRect>& rects);
 };
diff --git a/TrafficMonitor/SkinFile.cpp b/TrafficMonitor/SkinFile.cpp
@@ -527,9 +527,24 @@ void CSkinFile::DrawInfo(CDC* pDC, bool show_more_info, CFont& font)
         //绘制显示项目
         DrawItemsInfo(gdiplus_drawer, layout, font);
 
+        //重新设置自绘插件区域的alpha值。
+        //插件自绘时可能会使用GDI绘制文本，由于使用了UpdateLayeredWindow函数，使用GDI的绘图函数绘制文本时会导致文本变得透明。
+        //这里遍历所有插件自绘区域，将alpha值为0的部分修正为正确的alpha值。
+        std::vector<CRect> rects;
+        for (const auto& plugin_item : theApp.m_plugins.GetPluginItems())
+        {
+            const auto& layout_item = layout.GetItem(plugin_item);
+            if (plugin_item->IsCustomDraw() && layout_item.show)
+            {
+                CRect rect(CPoint(layout_item.x, layout_item.y), CSize(layout_item.width, m_layout_info.text_height));
+                rects.push_back(rect);
+            }
+        }
+        DrawCommonHelper::FixBitmapTextAlpha(hBitMap, m_alpha, rects);
+
         SIZE sizeWindow = rect.Size();
         POINT ptSrc = { 0,0 };
-        ::UpdateLayeredWindow(hWnd, pDC->GetSafeHdc(), nullptr, &sizeWindow, hdcMemory, &ptSrc, RGB(255, 0, 255), &bf, ULW_ALPHA);
+        ::UpdateLayeredWindow(hWnd, pDC->GetSafeHdc(), nullptr, &sizeWindow, hdcMemory, &ptSrc, 0, &bf, ULW_ALPHA);
 
         gdiplus_drawer.GetGraphics()->ReleaseHDC(hdcMemory);
         DeleteObject(hBitMap);
@@ -672,7 +687,8 @@ void CSkinFile::DrawItemsInfo(IDrawCommon& drawer, Layout& layout, CFont& font)
                     plugin->OnExtenedInfo(ITMPlugin::EI_VALUE_TEXT_COLOR, std::to_wstring(cl).c_str());
                     plugin->OnExtenedInfo(ITMPlugin::EI_DRAW_TASKBAR_WND, L"0");
                 }
-                drawer.SetTextColor(cl);
+                drawer.GetDC()->SetTextColor(cl);
+                drawer.GetDC()->SetBkMode(TRANSPARENT);
                 plugin_item->DrawItem(drawer.GetDC()->GetSafeHdc(), layout_item.x, layout_item.y, layout_item.width, m_layout_info.text_height, brightness >= 128);
             }
             else