We should check in advance whether we are using a console program. If we are not using a console program, setting the input and output language of Console will have no effect and will throw an exception. For example, when using WPF, an exception will be thrown here, causing the connection to fail

Author: xiangb-a

src/ModelContextProtocol.Core/Client/StdioClientTransport.cs

@@ -156,20 +156,21 @@ public async Task<ITransport> ConnectAsync(CancellationToken cancellationToken =
             // up the encoding from Console.InputEncoding. As such, when not targeting .NET Core,
             // we temporarily change Console.InputEncoding to no-BOM UTF-8 around the Process.Start
             // call, to ensure it picks up the correct encoding.
-#if NET
-            processStarted = process.Start();
-#else
+#if !NET
             Encoding originalInputEncoding = Console.InputEncoding;
-            try
-            {
-                Console.InputEncoding = StreamClientSessionTransport.NoBomUtf8Encoding;
-                processStarted = process.Start();
-            }
-            finally
+            if (HasConsole())
             {
-                Console.InputEncoding = originalInputEncoding;
+                try
+                {
+                    Console.InputEncoding = StreamClientSessionTransport.NoBomUtf8Encoding;
+                }
+                finally
+                {
+                    Console.InputEncoding = originalInputEncoding;
+                }
             }
 #endif
+            processStarted = process.Start();
 
             if (!processStarted)
             {
@@ -199,7 +200,13 @@ public async Task<ITransport> ConnectAsync(CancellationToken cancellationToken =
             throw new IOException("Failed to connect transport.", ex);
         }
     }
+    [DllImport("kernel32.dll")]
+    private static extern IntPtr GetConsoleWindow();
 
+    private static bool HasConsole()
+    {
+        try { return GetConsoleWindow() != IntPtr.Zero; } catch { return false; }
+    }
     internal static void DisposeProcess(
         Process? process, bool processRunning, TimeSpan shutdownTimeout, string endpointName)
     {