Use EnumWindows instead of FindWindow

Notepad.Extensions.Logging.FunctionalTest/Program.cs

@@ -18,9 +18,15 @@ namespace Notepad.Extensions.Logging.FunctionalTest
             var sp = sc.BuildServiceProvider();
             var logger = sp.GetRequiredService<ILogger<Program>>();
 
-            logger.LogWarning("Here is a warning.");
+            //logger.LogWarning("Here is a warning.");
-            logger.LogError(GetException(), "oh no!.");
+            //logger.LogError(GetException(), "oh no!.");
-            logger.LogInformation("Here is some info.");
+            //logger.LogInformation("Here is some info.");
+            //logger.LogInformation("here, have a nice 😋 emoji.");
+            logger.LogInformation(@"💧 Paul
+@paws101
+Replying to
+@yaakov_h
+But does it handle emoji injection?.");
         }
 
         static Exception GetException()

Notepad.Extensions.Logging/NativeMethods.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Runtime.InteropServices;
+using System.Text;
 
 namespace Microsoft.Extensions.Logging
 {
@@ -15,5 +16,13 @@ namespace Microsoft.Extensions.Logging
 
         [DllImport("User32.dll", CharSet = CharSet.Unicode, SetLastError = true)]
         public static extern IntPtr SendMessage(IntPtr hWnd, int Msg, IntPtr wParam, [MarshalAs(UnmanagedType.LPWStr)] string lParam);
+
+        public delegate bool EnumWindowsDelegate(IntPtr hWnd, IntPtr lParam);
+
+        [DllImport("user32.dll")]
+        public static extern bool EnumWindows(EnumWindowsDelegate lpEnumFunc, IntPtr lParam);
+
+        [DllImport("User32.dll")]
+        public static extern int GetWindowText(IntPtr hWndParent, StringBuilder sb, int maxCount);
     }
 }

Notepad.Extensions.Logging/WindowFinder.cs

@@ -1,4 +1,6 @@
 using System;
+using System.ComponentModel;
+using System.Text;
 
 namespace Microsoft.Extensions.Logging
 {
@@ -6,28 +8,66 @@ namespace Microsoft.Extensions.Logging
     {
         public static IntPtr FindNotepadWindow()
         {
-            var hwnd = FindMainWindow();
+            sb ??= new StringBuilder(4096);
-            IntPtr edit = NativeMethods.FindWindowEx(hwnd, IntPtr.Zero, "EDIT", null);
+
+            try
+            {
+                FindMainWindow();
+                if (handle == IntPtr.Zero)
+                {
+                    return handle;
+                }
+
+                IntPtr edit = NativeMethods.FindWindowEx(handle, IntPtr.Zero, "EDIT", null);
                 return edit;
             }
+            finally
+            {
+                handle = IntPtr.Zero;
+                sb.Clear();
+            }
+        }
 
         static IntPtr FindMainWindow()
         {
-            IntPtr hwnd;
+            NativeMethods.EnumWindows(enumWindowsDelegate, IntPtr.Zero);
-            
+            return handle;
-            hwnd = NativeMethods.FindWindow(null, "Untitled - Notepad");
-            if (hwnd != IntPtr.Zero)
-            {
-                return hwnd;
         }
 
-            hwnd = NativeMethods.FindWindow(null, "*Untitled - Notepad");
+        static NativeMethods.EnumWindowsDelegate enumWindowsDelegate = new NativeMethods.EnumWindowsDelegate(EnumWindowsCallback);
-            if (hwnd != IntPtr.Zero)
+
+        static bool EnumWindowsCallback(IntPtr hWnd, IntPtr lParam)
         {
-                return hwnd;
+            var result = NativeMethods.GetWindowText(hWnd, sb, sb.Capacity);
+            if (result < 0)
+            {
+                throw new Win32Exception(result);
             }
 
-            return IntPtr.Zero;
+            if (IsKnownNotepadWindow(sb.ToString()))
+            {
+                WindowFinder.handle = hWnd;
+                return false;
+            }
+            return true;
+        }
+
+        [ThreadStatic]
+        static IntPtr handle;
+
+        [ThreadStatic]
+        static StringBuilder sb;
+
+        static bool IsKnownNotepadWindow(string titleText)
+        {
+            switch (titleText)
+            {
+                case "Untitled - Notepad":
+                case "*Untitled - Notepad":
+                    return true;
+            }
+
+            return false;
         }
     }
 }