Filter ApplicationFrameWindows that don't actively host programs #54

The ApplicationFrameWindows that host Windows Store Apps like to
hang around in Windows 10 even after the underlying program has been
closed. A way to figure out if the ApplicationFrameWindow is
currently hosting an application is to check if it has a property called
"ApplicationViewCloakType", and that the value != 1.

I've stumbled upon these values of "ApplicationViewCloakType":
 0 = Program is running on current virtual desktop
 1 = Program is not running
 2 = Program is running on a different virtual desktop

Core/AppWindow.cs

@@ -113,6 +113,7 @@ public bool IsAltTabWindow()
             if (!IsOwnerOrOwnerNotVisible()) return false;
             if (HasITaskListDeletedProperty()) return false;
             if (IsCoreWindow()) return false;
+            if (IsApplicationFrameWindow() && !HasAppropriateApplicationViewCloakType()) return false;
 
             return true;
         }
@@ -176,6 +177,39 @@ private bool IsCoreWindow()
             return ClassName == "Windows.UI.Core.CoreWindow";
         }
 
+        private bool IsApplicationFrameWindow()
+        {
+            return ClassName == "ApplicationFrameWindow";
+        }
+
+        private bool HasAppropriateApplicationViewCloakType()
+        {
+            // The ApplicationFrameWindows that host Windows Store Apps like to
+            // hang around in Windows 10 even after the underlying program has been
+            // closed. A way to figure out if the ApplicationFrameWindow is
+            // currently hosting an application is to check if it has a property called
+            // "ApplicationViewCloakType", and that the value != 1.
+            //
+            // I've stumbled upon these values of "ApplicationViewCloakType":
+            //    0 = Program is running on current virtual desktop
+            //    1 = Program is not running
+            //    2 = Program is running on a different virtual desktop
+
+            var hasAppropriateApplicationViewCloakType = false;
+            WinApi.EnumPropsEx(HWnd, (hwnd, lpszString, data, dwData) =>  
+            {
+                var propName = Marshal.PtrToStringAnsi(lpszString);
+                if (propName == "ApplicationViewCloakType")
+                {
+                    hasAppropriateApplicationViewCloakType = data != 1;
+                    return 0;
+                }
+                return 1;
+            }, IntPtr.Zero);
+
+            return hasAppropriateApplicationViewCloakType;
+        }
+
         // This method only works on Windows >= Windows Vista
         private static string GetExecutablePath(int processId)
         {

Core/WinApi.cs

@@ -307,5 +307,9 @@ public enum SendMessageTimeoutFlags : uint
 
         [DllImport("user32.dll")]
         public static extern IntPtr GetProp(IntPtr hWnd, string lpString);
+
+        [DllImport("user32.dll")]
+        public static extern int EnumPropsEx(IntPtr hWnd, EnumPropsExDelegate lpEnumFunc, IntPtr lParam);
+        public delegate int EnumPropsExDelegate(IntPtr hwnd, IntPtr lpszString, long hData, long dwData);
     }
 }