feat: 添加了端口占用检测，若被占用则不会启动

server/src/UdpServer.cs

@@ -123,7 +123,15 @@ public class UDPServer
         {
             for (int i = 0; i < num; i++)
             {
-                listeners.Add(new UdpClient(this.listenPort + i));
+                int currentPort = this.listenPort + i;
+                if (IsPortInUse(currentPort))
+                {
+                    throw new ArgumentException(
+                        $"Port {currentPort} is already in use.",
+                        nameof(port)
+                    );
+                }
+                listeners.Add(new UdpClient(currentPort));
             }
             this.groupEP = new IPEndPoint(IPAddress.Any, listenPort);
         }
@@ -137,6 +145,29 @@ public class UDPServer
         }
     }
 
+    private bool IsPortInUse(int port)
+    {
+        bool inUse = false;
+        try
+        {
+            var ipGlobalProperties = IPGlobalProperties.GetIPGlobalProperties();
+            var udpListeners = ipGlobalProperties.GetActiveUdpListeners();
+            foreach (var ep in udpListeners)
+            {
+                if (ep.Port == port)
+                {
+                    inUse = true;
+                    break;
+                }
+            }
+        }
+        catch (Exception ex)
+        {
+            logger.Warn($"Failed to check port usage for port {port}: {ex.Message}");
+        }
+        return inUse;
+    }
+
     /// <summary>
     /// 异步寻找目标发送的内容
     /// </summary>