fix: locate WeChat tray icons using public shell metadata

src/WxAgent.Core/WechatLocators.cs

@@ -4,6 +4,12 @@ public static class WechatLocators
 {
     public const string MainView = "MainView";
     public const string MainTabBar = "MainView.main_tabbar";
+    // Observed with WeChat 4.1.13.63; query its public shell icon metadata, never post tray callback messages.
+    public const string TrayMessageWindowClass = "Qt51514WxTrayIconMessageWindowClass";
+    public const uint TrayIconId = 0;
+
+    public static bool IsNotificationAreaRoot(string className) =>
+        className is "Shell_TrayWnd" or "Shell_SecondaryTrayWnd" or "NotifyIconOverflowWindow";
 
     public static bool IsWechatTrayName(string name) =>
         name is "微信" or "WeChat" or "Weixin"

src/WxAgent.Windows/NativeMethods.txt

@@ -14,3 +14,6 @@ GetWindowRect
 AccessibleObjectFromWindow
 AccessibleChildren
 EnumChildWindows
+Shell_NotifyIconGetRect
+WindowFromPoint
+GetAncestor

src/WxAgent.Windows/WechatTray.cs

@@ -5,11 +5,13 @@ using FlaUI.UIA3;
 using Windows.Win32;
 using Windows.Win32.Foundation;
 using Windows.Win32.UI.Accessibility;
+using Windows.Win32.UI.Shell;
+using Windows.Win32.UI.WindowsAndMessaging;
 using WxAgent.Core;
 
 namespace WxAgent.Windows;
 
-public sealed record WechatTrayDiagnostic(int ToolbarCount, int IconCount, int WechatIconCount);
+public sealed record WechatTrayDiagnostic(int ToolbarCount, int IconCount, int WechatIconCount, string DetectionMethod = "MSAA");
 
 internal static class WechatTray
 {
@@ -23,7 +25,8 @@ internal static class WechatTray
         if (matches.Length == 0) return false;
         if (matches.Length != 1)
             throw new WxAgentException(WxAgentErrorCode.InvalidOperationState, "Multiple WeChat notification icons found; refusing an ambiguous target.");
-        matches[0].DoubleClick();
+        var bounds = matches[0].BoundingRectangle;
+        ActivateAt(new Point(bounds.Left + bounds.Width / 2, bounds.Top + bounds.Height / 2));
         return true;
     }
 
@@ -74,6 +77,20 @@ internal static class WechatTray
                     if (WechatLocators.IsWechatTrayName(text)) matches.Add((owner, child));
                 }
             }
+            if (matches.Count == 0)
+            {
+                var nativeBounds = FindKnownIconBounds();
+                if (activate)
+                {
+                    if (nativeBounds.Count != 1)
+                        throw new WxAgentException(WxAgentErrorCode.ControlNotFound,
+                            "No unique WeChat notification icon was found through accessibility or public shell metadata; no application was started.");
+                    cancellationToken.ThrowIfCancellationRequested();
+                    var bounds = nativeBounds[0];
+                    ActivateAt(new Point(bounds.Left + bounds.Width / 2, bounds.Top + bounds.Height / 2));
+                }
+                return new WechatTrayDiagnostic(toolbars.Count, icons, nativeBounds.Count, "Shell_NotifyIconGetRect");
+            }
             if (activate)
             {
                 if (matches.Count != 1)
@@ -84,8 +101,7 @@ internal static class WechatTray
                 if (width <= 0 || height <= 0 || (Convert.ToInt32(match.Owner.get_accState(match.Child)) & 0x10000) != 0)
                     throw new WxAgentException(WxAgentErrorCode.ControlNotFound, "The WeChat tray icon is in the hidden overflow area; reveal it before restoring.");
                 // Qt opens the original main window on a tray double-click, not MSAA's single default action.
-                Mouse.MoveTo(left + width / 2, top + height / 2);
-                Mouse.DoubleClick(MouseButton.Left);
+                ActivateAt(new Point(left + width / 2, top + height / 2));
             }
             return new WechatTrayDiagnostic(toolbars.Count, icons, matches.Count);
         }
@@ -95,6 +111,36 @@ internal static class WechatTray
         }
     }
 
+    private static unsafe List<Rectangle> FindKnownIconBounds()
+    {
+        var result = new List<Rectangle>();
+        foreach (var window in WechatNativeWindow.Enumerate().Where(window => window.ClassName == WechatLocators.TrayMessageWindowClass))
+        {
+            var identifier = new NOTIFYICONIDENTIFIER
+            {
+                cbSize = (uint)sizeof(NOTIFYICONIDENTIFIER),
+                hWnd = new HWND((nint)window.Handle),
+                uID = WechatLocators.TrayIconId
+            };
+            RECT bounds;
+            if (PInvoke.Shell_NotifyIconGetRect(&identifier, &bounds).Value == 0
+                && bounds.right > bounds.left && bounds.bottom > bounds.top)
+                result.Add(Rectangle.FromLTRB(bounds.left, bounds.top, bounds.right, bounds.bottom));
+        }
+        return result;
+    }
+
+    private static void ActivateAt(Point point)
+    {
+        var hit = PInvoke.WindowFromPoint(point);
+        var root = PInvoke.GetAncestor(hit, GET_ANCESTOR_FLAGS.GA_ROOT);
+        if (!PInvoke.IsWindowVisible(root) || !WechatLocators.IsNotificationAreaRoot(ReadClass(root)))
+            throw new WxAgentException(WxAgentErrorCode.InvalidOperationState,
+                "The notification icon is obscured or its overflow panel is closed; refusing an unverified click.");
+        Mouse.MoveTo(point);
+        Mouse.DoubleClick(MouseButton.Left);
+    }
+
     private static string ReadClass(HWND hwnd)
     {
         Span<char> text = stackalloc char[256];

tests/WxAgent.Core.Tests/WechatStabilityTests.cs

@@ -167,6 +167,18 @@ public sealed class WechatStabilityTests
         finally { Directory.Delete(directory, recursive: true); }
     }
 
+    [Theory]
+    [InlineData("Shell_TrayWnd", true)]
+    [InlineData("Shell_SecondaryTrayWnd", true)]
+    [InlineData("NotifyIconOverflowWindow", true)]
+    [InlineData("Qt51514QWindowIcon", false)]
+    [InlineData("Chrome_WidgetWin_1", false)]
+    [InlineData("", false)]
+    public void TrayClicks_RequireANotificationAreaHitTarget(string className, bool expected)
+    {
+        Assert.Equal(expected, WechatLocators.IsNotificationAreaRoot(className));
+    }
+
     private static WechatStabilitySample Sample(
         DateTimeOffset timestamp,
         long memory,