using System.Net.NetworkInformation;
bool isLocalAreaConnected = NetworkInterface.GetIsNetworkAvailable();
if (isLocalAreaConnected)
{
Common.MessageBox.ShowMes(this,"有链接");
}
using System.IO;
using System.Runtime.InteropServices;//引入这两个命名空间，不用引用wininet.dll [DllImport("wininet.dll")]
private extern static bool InternetGetConnectedState(out int connectionDescription, int reservedValue);
//以及判断网络连接的函数：
private bool IsConnected()
{ int I = ; bool state = InternetGetConnectedState(out I, ); return state; } protected void Button1_Click(object sender, EventArgs e)
{
if (IsConnected())
{
Label1.Text = "状态:网络畅通!";
}
else
{
Label1.Text = "状态:与目标网络无连接！";
}
}
//这个方法有时不是那么好用，因为禁止ping域名是某些服务商防范黑客攻击的一种手段
/// <summary>
/// ping 具体的网址看能否ping通
/// </summary>
/// <param name="strNetAdd"></param>
/// <returns></returns>
private static bool PingNetAddress(string strNetAdd)
{
bool Flage = false;
Ping ping = new Ping();
try
{
PingReply pr = ping.Send(strNetAdd, );
if (pr.Status == IPStatus.TimedOut)
{
Flage = false;
}
if (pr.Status == IPStatus.Success)
{
Flage = true;
}
else
{
Flage = false;
}
}
catch
{
Flage = false;
}
return Flage;
}
判断远程有无此文件 using System.Net;
private bool RemoteFileExists(string fileUrl)
{
try
{
HttpWebRequest re = (HttpWebRequest)WebRequest.Create(fileUrl);
HttpWebResponse res = (HttpWebResponse)re.GetResponse();
if (res.ContentLength != )
{
return true;
//MessageBox.Show("文件存在"); return true;
}
}
catch (Exception)
{
//Response.Write("不存在");
return false;
}
return false;
}
判断远程有无此文件
using System.Net;
public static bool IsExist(string uri)
{
HttpWebRequest req = null;
HttpWebResponse res = null;
try
{
req = (HttpWebRequest)WebRequest.Create(uri);
req.Method = "HEAD";
req.Timeout = ;
res = (HttpWebResponse)req.GetResponse();
return (res.StatusCode == HttpStatusCode.OK);
}
catch
{
return false;
}
finally
{
if (res != null)
{
res.Close();
res = null;
}
if (req != null)
{
req.Abort();
req = null;
}
}
}
//2:
private bool UrlExistsUsingXmlHttp(string url)
{
//注意：此方法需要引用Msxml2.dll( 项目－－－添加引用－－com---microsoft xml 2.6)
MSXML2.XMLHTTP _xmlhttp = new MSXML2.XMLHTTPClass();
_xmlhttp.open("HEAD", url, false, null, null);
_xmlhttp.send("");
return (_xmlhttp.status == );
}
//3:
private bool UrlExistsUsingSockets(string url)
{
if (url.StartsWith("http://")) url = url.Remove(, "http://".Length);
try
{
System.Net.IPHostEntry ipHost = System.Net.Dns.GetHostEntry(url);// System.Net.Dns.Resolve(url);
return true;
}
catch (System.Net.Sockets.SocketException se)
{
System.Diagnostics.Trace.Write(se.Message);
return false;
}
}
c#关于判断网络连接正常与否的总结
本人最近做c#winform的项目，遇到了判断网络是否正常连接的问题。后来查出了以下几种方法，供大家学习参考。
.方法一
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Windows.Forms;
using System.Net.Sockets;
using System.Threading;
namespace WindowsFormsApplication1
{
public partial class Demo : Form
{
public Demo()
{
InitializeComponent();
}
//判断
private void btpanduan_Click(object sender, EventArgs e)
{
//210.192.120.228 163网易
string ip = this.txtip.Text.ToString();
int port = Convert .ToInt32( this.txtport.Text.ToString());
bool a = panduan(ip, port );//135为本机服务端口号
if (a == true)
{
MessageBox.Show("该网络连接正常 ！");
}
else
{
MessageBox.Show("该网络连接不畅通 ！");
}
} // 异步调用 //判断的方法
public bool panduan(string ip, int port)
{
try
{
TcpClient client = new TcpClient(ip, port);
if (client.Connected)
{
return true;
}
else
{
return false;
}
}
catch
{
return false;
}
}
}
} .利用 c# ping类
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Net;
namespace WindowsFormsApplication1
{
public partial class Demo3 : Form
{
public Demo3()
{
InitializeComponent();
}
System.Net.NetworkInformation.Ping ping = new System.Net.NetworkInformation.Ping();
System.Net.NetworkInformation.PingReply res;
//检查网络连接
private void btcheck_Click(object sender, EventArgs e)
{
string url = this.txturl.Text.ToString();
bool a = check(url);
if (a == true)
{
MessageBox.Show("连接成功！", "提示信息");
}
else
{
MessageBox.Show("连接失败！", "提示信息");
}
}
public bool check(string url)
{
try
{
res = ping.Send(url);
if (res.Status == System.Net.NetworkInformation.IPStatus.Success)
{
return true;
}
else
{
return false;
}
}
catch {
return false;
}
}
}
} 摘自 wanglei_smartfish的专栏