TcpClient，去除 Connected 属性（不可靠），增加 Online 属性用于判断在线状态。

Apewer/Network/Extension.cs → Apewer/Network/Extensions.cs

@@ -9,7 +9,7 @@ namespace Apewer.Network
 {
 
     /// <summary>扩展方法。</summary>
-    public static class Extension
+    public static class Extensions
     {
 
         /// <summary>添加邮件账户。</summary>
@@ -155,15 +155,31 @@ namespace Apewer.Network
             return json;
         }
 
+        /// <summary>检查 Socket 在线状态。</summary>
+        /// <exception cref="NotSupportedException"></exception>
+        /// <exception cref="ObjectDisposedException"></exception>
+        /// <exception cref="SocketException"></exception>
+        public static bool Online(this Socket socket)
+        {
+            if (socket == null) return false;
+
+            var pending = socket.Poll(1000, System.Net.Sockets.SelectMode.SelectRead);
+            var available = socket.Available;
+            var offline = pending && available == 0;
+            return !offline;
+        }
+
         /// <summary>从套接字接收数据。</summary>
         /// <exception cref="ArgumentNullException"></exception>
         /// <exception cref="ArgumentOutOfRangeException"></exception>
+        /// <exception cref="InvalidOperationException"></exception>
         /// <exception cref="SocketException"></exception>
         /// <exception cref="ObjectDisposedException"></exception>
         /// <exception cref="System.Security.SecurityException"></exception>
         public static byte[] Receive(this Socket socket, int maxLength = 1024)
         {
             if (socket == null) throw new ArgumentNullException(nameof(socket));
+            if (maxLength < 0 || maxLength > 65535) throw new ArgumentOutOfRangeException(nameof(maxLength));
 
             var buffer = new byte[maxLength];
             var received = socket.Receive(buffer, 0, maxLength, SocketFlags.None);

Apewer/Network/TcpClient.cs

@@ -1,13 +1,6 @@
-using Apewer;
-using Apewer.Internals;
-using System;
-using System.Collections;
-using System.Collections.Generic;
-using System.IO;
+using System;
 using System.Net;
 using System.Net.Sockets;
-using System.Text;
-using System.Threading;
 
 namespace Apewer.Network
 {
@@ -16,13 +9,19 @@ namespace Apewer.Network
     public class TcpClient : IDisposable
     {
 
-        Socket _client = null;
+        Socket _socket = null;
 
         /// <summary>套接字实例。</summary>
-        public Socket Socket { get => _client; }
+        public Socket Socket { get => _socket; }
 
-        /// <summary>已连接。</summary>
-        public bool Connected { get => _client != null && _client.Connected; }
+        /// <summary>在线。</summary>
+        public bool Online { get => Extensions.Online(_socket); }
+
+        /// <summary>本地终结点。</summary>
+        public IPEndPoint LocalEndPoint { get; private set; }
+
+        /// <summary>远程终结点。</summary>
+        public IPEndPoint RemoteEndPoint { get; private set; }
 
         /// <summary>启动客户端，并连接到服务端。</summary>
         public TcpClient(string ip, int port) : this(IPAddress.Parse(ip), port) { }
@@ -33,18 +32,20 @@ namespace Apewer.Network
         /// <summary>启动客户端，并连接到服务端。</summary>
         public TcpClient(IPEndPoint endpoint)
         {
-            _client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
-            _client.Connect(endpoint);
-            _client.SendTimeout = 5000;
+            _socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
+            _socket.Connect(endpoint);
+            _socket.SendTimeout = 5000;
+            LocalEndPoint = _socket.LocalEndPoint as IPEndPoint;
+            RemoteEndPoint = endpoint;
         }
 
         /// <summary>关闭连接，释放系统资源。</summary>
         public void Dispose()
         {
-            try { _client.Disconnect(false); } catch { }
-            try { _client.Close(100); } catch { }
+            try { _socket.Disconnect(false); } catch { }
+            try { _socket.Close(100); } catch { }
 #if !NET20
-            try { _client.Dispose(); } catch { }
+            try { _socket.Dispose(); } catch { }
 #endif
         }
 
@@ -54,13 +55,13 @@ namespace Apewer.Network
         /// <exception cref="SocketException"></exception>
         /// <exception cref="ObjectDisposedException"></exception>
         /// <exception cref="System.Security.SecurityException"></exception>
-        public byte[] Receive(int maxLength = 1024) => _client.Receive(maxLength);
+        public byte[] Receive(int maxLength = 1024) => _socket.Receive(maxLength);
 
         /// <summary>发送。</summary>
         /// <exception cref="ArgumentNullException" />
         /// <exception cref="SocketException" />
         /// <exception cref="ObjectDisposedException" />
-        public void Send(byte[] data) => _client.Send(data);
+        public void Send(byte[] data) => _socket.Send(data);
 
     }