Refactor: split ScanScreen window-capture into 3 private methods

client/ScreenSpy.cpp

@@ -171,8 +171,43 @@ LPBYTE CScreenSpy::GetFirstScreenData(ULONG* ulFirstScreenLength)
 VOID CScreenSpy::ScanScreen(HDC hdcDest, HDC hdcSour, ULONG ulWidth, ULONG ulHeight)
 {
     if (m_hTargetWnd || m_bDynamicForeground) {
-        // 动态前景模式：每帧查询当前前景窗口，切换时尺寸不变则直接复用，尺寸变化则触发重建
+        if (m_bDynamicForeground && !UpdateDynamicForeground()) return;
-        if (m_bDynamicForeground) {
+        if (IsIconic(m_hTargetWnd)) return;
+        if (!CheckWindowResize()) return;
+        CaptureWindowContent(hdcDest, hdcSour, ulWidth, ulHeight);
+        return;
+    }
+    if (m_bVirtualPaint) {
+        RECT rcFill = { 0, 0, (LONG)ulWidth, (LONG)ulHeight };
+        HBRUSH hBrush = CreateSolidBrush(RGB(30, 30, 30));
+        FillRect(hdcDest, &rcFill, hBrush);
+        DeleteObject(hBrush);
+        int n = 0;
+        if (n = EnumWindowsTopToDown(NULL, EnumHwndsPrint, (LPARAM)&m_data.SetScreenDC(hdcDest))) {
+            Mprintf("EnumWindowsTopToDown failed: %d!!! GetLastError: %d\n", n, GetLastError());
+            Sleep(50);
+        }
+        return;
+    }
+    AUTO_TICK(70, "");
+#if COPY_ALL
+    BitBlt(hdcDest, 0, 0, ulWidth, ulHeight, hdcSour, m_iScreenX, m_iScreenY, SRCCOPY);
+#else
+    const ULONG ulJumpLine  = 50;
+    const ULONG ulJumpSleep = ulJumpLine / 10;
+    for (int i = 0, ulToJump = 0; i < (int)ulHeight; i += ulToJump) {
+        ULONG ulv1 = ulHeight - i;
+        ulToJump = (ulv1 > ulJumpLine) ? ulJumpLine : ulv1;
+        BitBlt(hdcDest, 0, i, ulWidth, ulToJump, hdcSour, 0, i, SRCCOPY);
+        Sleep(ulJumpSleep);
+    }
+#endif
+}
+
+// 每帧跟踪前景窗口；切换时尺寸相同直接复用，尺寸不同触发重建
+// 返回 false 表示本帧跳过（冻结）
+bool CScreenSpy::UpdateDynamicForeground()
+{
     HWND fg = GetForegroundWindow();
     if (fg && fg != m_hTargetWnd) {
         RECT wndRc = {}, frameRc = {};
@@ -182,13 +217,12 @@ VOID CScreenSpy::ScanScreen(HDC hdcDest, HDC hdcSour, ULONG ulWidth, ULONG ulHei
         ULONG newW = (ULONG)(frameRc.right - frameRc.left);
         ULONG newH = (ULONG)(frameRc.bottom - frameRc.top);
         if (newW != m_ulFullWidth || newH != m_ulFullHeight) {
-                    // 尺寸不同：触发重建，同时把新 HWND 写入 m_NextTargetWnd，
+            // 尺寸不同：让 WorkThread 重建，m_NextTargetWnd 传递新 HWND
-                    // 让 WorkThread 在重建前同步更新 CScreenManager::m_hTargetWnd
             m_NextTargetWnd = fg;
             m_bNeedRestart = true;
-                    return;
+            return false;
         }
-                // 尺寸相同：直接切换，更新阴影偏移和缓存，无需重建
+        // 尺寸相同：直接切换，更新阴影偏移缓存，无需重建
         m_ShadowLeft  = frameRc.left - wndRc.left;
         m_ShadowTop   = frameRc.top  - wndRc.top;
         m_CachedWndW  = wndRc.right  - wndRc.left;
@@ -197,34 +231,30 @@ VOID CScreenSpy::ScanScreen(HDC hdcDest, HDC hdcSour, ULONG ulWidth, ULONG ulHei
         m_hTargetWnd  = fg;
         Mprintf("CScreenSpy: 前景切换(同尺寸) -> HWND=%p\n", fg);
     }
-            if (!m_hTargetWnd) return; // 当前无前景窗口，冻结上一帧
+    return m_hTargetWnd != NULL; // NULL=无前景窗口，冻结上一帧
-        }
+}
 
-        // 最小化：不绘制，hdcDest 保留上一帧内容（远程端看到冻结画面）
+// 检测窗口 resize：GetWindowRect 每帧调用；DWM 查询仅在尺寸稳定 300ms 后触发
-        if (IsIconic(m_hTargetWnd)) return;
+// 同时更新 m_iScreenX/Y（窗口移动时坐标同步），返回 false 表示本帧跳过
-
+bool CScreenSpy::CheckWindowResize()
-        // 检测窗口尺寸变化：GetWindowRect 廉价，每帧调用；
+{
-        // DwmGetWindowAttribute 较重，仅在 GetWindowRect 尺寸稳定后才调用。
-        // 防抖策略：拖拽 resize 期间尺寸持续变化，冻结画面等待稳定 300ms 后再重建，
-        // 避免拖拽过程中每帧重建 DIBSection / 重发 BitmapInfo / 重置编解码器。
     static const DWORD RESIZE_DEBOUNCE_MS = 300;
     RECT fullRc = {};
     GetWindowRect(m_hTargetWnd, &fullRc);
-        // 窗口每帧都可能移动，实时更新屏幕偏移，保证 PointConversion 坐标正确
     m_iScreenX = fullRc.left + m_ShadowLeft;
     m_iScreenY = fullRc.top  + m_ShadowTop;
     int w = fullRc.right - fullRc.left;
     int h = fullRc.bottom - fullRc.top;
-        if (w != m_CachedWndW || h != m_CachedWndH) {
+    if (w == m_CachedWndW && h == m_CachedWndH)
+        return true;
     // 尺寸有变化：更新防抖记录
     if (w != m_PendingWndW || h != m_PendingWndH) {
         m_PendingWndW    = w;
         m_PendingWndH    = h;
         m_SizeChangeTick = GetTickCount();
     }
-            // 尚未稳定：冻结当前帧，继续等待
     if (GetTickCount() - m_SizeChangeTick < RESIZE_DEBOUNCE_MS)
-                return;
+        return false; // 尚未稳定，冻结等待
     // 稳定 300ms：查询 DWM 真实帧边界，决定是否重建
     RECT frameRc = fullRc;
     if (SUCCEEDED(DwmGetWindowAttribute(m_hTargetWnd, DWMWA_EXTENDED_FRAME_BOUNDS, &frameRc, sizeof(frameRc)))) {
@@ -239,54 +269,23 @@ VOID CScreenSpy::ScanScreen(HDC hdcDest, HDC hdcSour, ULONG ulWidth, ULONG ulHei
             m_ulFullWidth, m_ulFullHeight,
             frameRc.right - frameRc.left, frameRc.bottom - frameRc.top);
         m_bNeedRestart = true;
-                return;
+        return false;
     }
     m_CachedWndW = w;
     m_CachedWndH = h;
-        }
+    return true;
+}
 
-        // PrintWindow → 临时 DC → BitBlt 到目标（用缓存的阴影偏移跳过 DWM 扩展帧）
+// 前景模式直接 BitBlt（零闪烁）；指定窗口模式用 PrintWindow（处理遮挡）
+void CScreenSpy::CaptureWindowContent(HDC hdcDest, HDC hdcSour, ULONG ulWidth, ULONG ulHeight)
+{
+    if (m_bDynamicForeground) {
+        BitBlt(hdcDest, 0, 0, ulWidth, ulHeight, hdcSour, m_iScreenX, m_iScreenY, SRCCOPY);
+    } else {
         HDC hTmp = m_data.GetWindowDC();
         HBITMAP hOld = (HBITMAP)SelectObject(hTmp, m_data.GetWindowBmp());
-        BOOL ok = PrintWindow(m_hTargetWnd, hTmp, PW_RENDERFULLCONTENT);
+        if (PrintWindow(m_hTargetWnd, hTmp, PW_RENDERFULLCONTENT))
-        if (!ok) ok = PrintWindow(m_hTargetWnd, hTmp, 0);
-        if (ok) {
             BitBlt(hdcDest, 0, 0, ulWidth, ulHeight, hTmp, m_ShadowLeft, m_ShadowTop, SRCCOPY);
-        }
         SelectObject(hTmp, hOld);
-        return;
     }
-
-    if (m_bVirtualPaint) {
-        // 先用深色填充背景，避免窗口移动时留下残影
-        RECT rcFill = { 0, 0, (LONG)ulWidth, (LONG)ulHeight };
-        HBRUSH hBrush = CreateSolidBrush(RGB(30, 30, 30));  // 深灰色背景
-        FillRect(hdcDest, &rcFill, hBrush);
-        DeleteObject(hBrush);
-
-        int n = 0;
-        if (n = EnumWindowsTopToDown(NULL, EnumHwndsPrint, (LPARAM)&m_data.SetScreenDC(hdcDest))) {
-            Mprintf("EnumWindowsTopToDown failed: %d!!! GetLastError: %d\n", n, GetLastError());
-            Sleep(50);
-        }
-        return;
-    }
-    AUTO_TICK(70, "");
-#if COPY_ALL
-    BitBlt(hdcDest, 0, 0, ulWidth, ulHeight, hdcSour, m_iScreenX, m_iScreenY, SRCCOPY);
-#else
-    const ULONG	ulJumpLine = 50;
-    const ULONG	ulJumpSleep = ulJumpLine / 10;
-
-    for (int i = 0, ulToJump = 0; i < ulHeight; i += ulToJump) {
-        ULONG  ulv1 = ulHeight - i;
-
-        if (ulv1 > ulJumpLine)
-            ulToJump = ulJumpLine;
-        else
-            ulToJump = ulv1;
-        BitBlt(hdcDest, 0, i, ulWidth, ulToJump, hdcSour,0, i, SRCCOPY);
-        Sleep(ulJumpSleep);
-    }
-#endif
 }

client/ScreenSpy.h

@@ -266,6 +266,14 @@ public:
         m_hDeskTopDC = GetDC(NULL);
         m_data.Create(m_hDeskTopDC, m_iScreenX, m_iScreenY, m_ulFullWidth, m_ulFullHeight);
     }
+
+private:
+    // 前景跟踪：切换或尺寸变化时更新 m_hTargetWnd，返回 false 表示本帧冻结
+    bool UpdateDynamicForeground();
+    // 防抖 + 重建检测：更新 m_iScreenX/Y，返回 false 表示本帧冻结
+    bool CheckWindowResize();
+    // 执行实际像素拷贝（BitBlt 或 PrintWindow）
+    void CaptureWindowContent(HDC hdcDest, HDC hdcSour, ULONG ulWidth, ULONG ulHeight);
 };
 
 #endif // !defined(AFX_SCREENSPY_H__5F74528D_9ABD_404E_84D2_06C96A0615F4__INCLUDED_)