C#获取网络链接状态的几种方法(己封装为类)
本人从事编程也几年了,一直在互联网中排徊,平时遇到问题也是baidu或google什么的,一直都没有想着去记录想法的一些技术文章,今天是元旦,老婆又刚好回家了,所以在这里就发表我的第一篇文章吧,呵呵
现在很多项目中都需要网络来支持,使网络链接检测就成为了很普遍的问题... 好了,废话就不多说了,首先这里祝大家元旦快乐!!直入主题吧!
Internet.cs
using System; using System.Web; using System.Net.Sockets; using System.Runtime.InteropServices; using System.Threading; namespace VvxT.Web { public class Internet { #region 利用API方式获取网络链接状态 private static int NETWORK_ALIVE_LAN = 0x00000001; private static int NETWORK_ALIVE_WAN = 0x00000002; private static int NETWORK_ALIVE_AOL = 0x00000004; [DllImport("sensapi.dll")] private extern static bool IsNetworkAlive(ref int flags); [DllImport("sensapi.dll")] private extern static bool IsDestinationReachable(string dest, IntPtr ptr); [DllImport("wininet.dll")] private extern static bool InternetGetConnectedState(out int connectionDescription, int reservedValue); public Internet() { } public static bool IsConnected() { int desc = 0; bool state = InternetGetConnectedState(out desc, 0); return state; } public static bool IsLanAlive() { return IsNetworkAlive(ref NETWORK_ALIVE_LAN); } public static bool IsWanAlive() { return IsNetworkAlive(ref NETWORK_ALIVE_WAN); } public static bool IsAOLAlive() { return IsNetworkAlive(ref NETWORK_ALIVE_AOL); } public static bool IsDestinationAlive(string Destination) { return (IsDestinationReachable(Destination, IntPtr.Zero)); } #endregion /// <summary> /// 在指定时间内尝试连接指定主机上的指定端口。 (默认端口:80,默认链接超时:5000毫秒) /// </summary> /// <param name="HostNameOrIp">主机名称或者IP地址</param> /// <param name="port">端口</param> /// <param name="timeOut">超时时间</param> /// <returns>返回布尔类型</returns> public static bool IsHostAlive(string HostNameOrIp, int? port, int? timeOut) { TcpClient tc = new TcpClient(); tc.SendTimeout = timeOut ?? 5000; tc.ReceiveTimeout = timeOut ?? 5000; bool isAlive; try { tc.Connect(HostNameOrIp, port ?? 80); isAlive = true; } catch { isAlive = false; } finally { tc.Close(); } return isAlive; } } public class TcpClientConnector { /// <summary> /// 在指定时间内尝试连接指定主机上的指定端口。 (默认端口:80,默认链接超时:5000毫秒) /// </summary> /// <param name= "hostname ">要连接到的远程主机的 DNS 名。</param> /// <param name= "port ">要连接到的远程主机的端口号。 </param> /// <param name= "millisecondsTimeout ">要等待的毫秒数,或 -1 表示无限期等待。</param> /// <returns>已连接的一个 TcpClient 实例。</returns> public static TcpClient Connect(string hostname, int? port, int? millisecondsTimeout) { ConnectorState cs = new ConnectorState(); cs.Hostname = hostname; cs.Port = port ?? 80; ThreadPool.QueueUserWorkItem(new WaitCallback(ConnectThreaded), cs); if (cs.Completed.WaitOne(millisecondsTimeout ?? 5000, false)) { if (cs.TcpClient != null) return cs.TcpClient; return null; //throw cs.Exception; } else { cs.Abort(); return null; //throw new SocketException(11001); // cannot connect } } private static void ConnectThreaded(object state) { ConnectorState cs = (ConnectorState)state; cs.Thread = Thread.CurrentThread; try { TcpClient tc = new TcpClient(cs.Hostname, cs.Port); if (cs.Aborted) { try { tc.GetStream().Close(); } catch { } try { tc.Close(); } catch { } } else { cs.TcpClient = tc; cs.Completed.Set(); } } catch (Exception e) { cs.Exception = e; cs.Completed.Set(); } } private class ConnectorState { public string Hostname; public int Port; public volatile Thread Thread; public readonly ManualResetEvent Completed = new ManualResetEvent(false); public volatile TcpClient TcpClient; public volatile Exception Exception; public volatile bool Aborted; public void Abort() { if (Aborted != true) { Aborted = true; try { Thread.Abort(); } catch { } } } } } }
使用方法:
Default.aspx.cs
using System; using System.Collections.Generic; using System.Web; using System.Web.UI; using System.Web.UI.WebControls; using System.Net.Sockets; namespace VvxT.Web { public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { bool IsConnected = Internet.IsConnected(); bool IsAOLAlive = Internet.IsAOLAlive(); DateTime oldTime1 = DateTime.Now; bool IsDestinationAlive = Internet.IsDestinationAlive("cn.yahoo.com"); DateTime newTime1 = DateTime.Now; TimeSpan ts1 = newTime1 - oldTime1; bool IsLanAlive = Internet.IsLanAlive(); bool IsWanAlive = Internet.IsWanAlive(); DateTime oldTime2 = DateTime.Now; //bool IsHostAlive = Internet.IsHostAlive("hk.yahoo.com", null, null);//不推荐使用(无法实际控制超时时间) bool IsHostAlive; TcpClient tc = TcpClientConnector.Connect("hk.yahoo.com", null, null);//推荐使用(采用线程池强行中断超时时间) try { if (tc != null) { tc.GetStream().Close(); tc.Close(); IsHostAlive = true; } else IsHostAlive = false; } catch { IsHostAlive = false; } DateTime newTime2 = DateTime.Now; TimeSpan ts2 = newTime2 - oldTime2; Response.Write("Connect:" + IsConnected + "<br />"); Response.Write("Lan:" + IsLanAlive + "<br />"); Response.Write("Wan:" + IsWanAlive + "<br />"); Response.Write("Aol:" + IsAOLAlive + "<br />"); Response.Write("Sip(cn.yahoo.com):" + IsDestinationAlive + " 耗时:" + ts1.TotalMilliseconds + "<br />"); Response.Write("TcpClient(hk.yahoo.com):" + IsHostAlive + " 耗时:" + ts2.TotalMilliseconds + "<br />"); } } }
测试显示效果:
Connect:True
Lan:True
Wan:True
Aol:True
Sip(cn.yahoo.com):True 耗时:265.625
TcpClient(hk.yahoo.com):False 耗时:5000
本文部分代码摘自网络,原作者未知,如有冒犯,请给我留言,我会及时更正,谢谢!
此类可用于C/S和B/S结构,以上测试环境为WebApplication。
写的不好的请多多指教!