我对c＃/ .net开发有点新手，但我已经为我公司的一小部分资产整理了一个股票跟踪应用程序。我还在SQL 2000中设置了它连接的数据库。
当网络连接可用时，它目前工作得非常出色，但是当我远离连接时，我想扩展它以供使用。
首先，我需要知道是否有可用的连接。所以我把它放在一起：
private int availableNetAdapters()
{
int nicCount = 0;
foreach (NetworkInterface nic in NetworkInterface.GetAllNetworkInterfaces())
{
if (nic.OperationalStatus == OperationalStatus.Up)
{
nicCount++;
}
}
return nicCount;
}
似乎工作，但我必须测试“＆gt; 1”，因为无论其他适配器状态如何，始终都会检测到“MS TCP Loopback接口”。
是否有更好/更简单的方法来检查连接？
答案 0 :(得分：9)
System.Net.NetworkInformation.NetworkInterface.GetIsNetworkAvailable()
您还可以使用该类中的事件NetworkAvailabilityChanged和NetworkAddressChanged来监控IP地址和网络可用性更改。
编辑：请注意，此方法会检查计算机上可能存在的所有可用网络接口（无线，局域网等）。如果其中任何一个已连接，它将返回true。
答案 1 :(得分：8)
还有一些事情需要记住：
因此，通常最好直接测试对所需特定资源的访问。
这些资源不稳定;无论如何，你必须处理异常。因此，通常最好只获取一个资源，就像你确定它确实存在一样，并将开发时间用于确保你的异常处理程序在失败方面做得很好。
答案 2 :(得分：4)
这是班级
using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Diagnostics;
namespace Ping
{
public readonly int iSent = 0;
public readonly int iReceived = 0;
public readonly int iLost = 0;
public PingReceivedArgs (int iSent, int iReceived, int iLost)
{
this.iSent = iSent;
this.iReceived = iReceived;
this.iLost = iLost;
}
public class PingFailedArgs : EventArgs
{
public readonly int iSent = 0;
public readonly int iReceived = 0;
public readonly int iLost = 0;
public PingFailedArgs (int iSent, int iReceived, int iLost)
{
this.iSent = iSent;
this.iReceived = iReceived;
this.iLost = iLost;
}
}
/// <summary>
/// The Main Ping Class
/// </summary>
public class Ping
{
//Create delegate for events
public delegate void PingReceivedHandler(object DataObj, PingReceivedArgs PingReceived);
public delegate void PingFailedHandler(object DataObj, PingFailedArgs PingFailed);
//The events we publish
public event PingReceivedHandler OnPingReceived;
public event PingFailedHandler OnPingFailed;
private void FirePingReceivedEvent( int iSent, int iReceived, int iLost)
{
PingReceivedArgs NewStatus = new PingReceivedArgs(iSent, iReceived, iLost);
if (OnPingReceived != null)
{
OnPingReceived(this,NewStatus);
}
}
private void FirePingFailedEvent(int iSent, int iReceived, int iLost)
{
PingFailedArgs NewStatus = new PingFailedArgs(iSent, iReceived, iLost);
if (OnPingFailed != null)
{
OnPingFailed(this,NewStatus);
}
}
private string _Host = "";
private bool _HostFound = false;
private int _PingSent = 0;
private int _PingReceived = 0;
private int _PingLost = 0;
private int _PauseBetweenPings = 2000;
private Thread _PingThread;
public string Host
{
get { return _Host; }
set { _Host = value; }
}
public bool HostFound
{
get { return _HostFound; }
}
public int PingSent
{
get { return _PingSent; }
}
public int PingReceived
{
get { return _PingReceived; }
}
public int PingLost
{
get { return _PingLost; }
}
public int PauseBetweenPings
{
get { return _PauseBetweenPings; }
set { _PauseBetweenPings = value; }
}
public Ping()
{
//
// TODO: Add constructor logic here
//
}
public void StartPinging()
{
try
{
if (_Host.Length == 0)
{
//LogStatus.WriteLog("Host name is blank, stopping.","Error","StartPinging");
return;
}
if (_PingThread == null || (_PingThread.ThreadState & (System.Threading.ThreadState.Unstarted | System.Threading.ThreadState.Background)) == 0)
{
_PingThread = new Thread(new ThreadStart(LoopAndPing));
_PingThread.IsBackground = true;
_PingThread.Start();
}
}
catch( Exception ex)
{
//LogStatus.WriteErrorLog(ex,"Error","StartPinging");
}
}
public void StopPinging()
{
try
{
if (_PingThread != null && (_PingThread.ThreadState & (System.Threading.ThreadState.Stopped | System.Threading.ThreadState.Aborted | System.Threading.ThreadState.Unstarted | System.Threading.ThreadState.AbortRequested)) == 0)
{
_PingThread.Abort();
_PingThread.Join();
}
}
catch (Exception ex)
{
//LogStatus.WriteErrorLog(ex, "Error", "StopPinging");
}
}
/// <summary>
/// LoopAndPing: Runs from a thread. Basically loops and gathers stats.
/// </summary>
private void LoopAndPing()
{
bool bHostFound = false;
try
{
while(true)
{
_PingSent++;
bHostFound = PingHost(_Host);
if (bHostFound)
{
_PingReceived++;
_HostFound = true;
FirePingReceivedEvent(_PingSent,_PingReceived,_PingLost);
}
else
{
_PingLost++;
_HostFound = false;
FirePingFailedEvent(_PingSent,_PingReceived,_PingLost);
}
Thread.Sleep(_PauseBetweenPings);
}
}
catch(ThreadAbortException)
{
//No need to do anything!
}
catch(Exception e)
{
//LogStatus.WriteErrorLog(e,"Error","LoopAndPing");
}
}
/// <summary>
/// PingHost - Send one ping to the host
/// </summary>
/// <param name="host">Can be an IP or Host name.</param>
/// <returns></returns>
public bool PingHost(string szHost)
{
bool bPingWorked = false;
try
{
string szCommand = "ping " + szHost + " -n 1";
Process p = new Process();
p.StartInfo.FileName = "cmd.exe";
p.StartInfo.Arguments = "/Q /A /C" + szCommand;
p.StartInfo.UseShellExecute = false;
p.StartInfo.RedirectStandardOutput = true;
p.StartInfo.RedirectStandardError = true;
p.StartInfo.CreateNoWindow = true;
p.Start();
string szCommandOutput = p.StandardOutput.ReadToEnd();
p.WaitForExit();
if (szCommandOutput.ToUpper().IndexOf("REPLY FROM") > -1)
{
bPingWorked = true;
}
}
catch(ThreadAbortException)
{
//No need to do anything!
}
catch(Exception e)
{
//LogStatus.WriteErrorLog(e,"Error","PingHost");
}
return bPingWorked;
}
}
}
从客户端拨打
PingHost = new Ping();
PingHost.OnPingFailed += new Ping.PingFailedHandler(PingHost_OnPingFailed);
PingHost.OnPingReceived +=new Ping.PingReceivedHandler(PingHost_OnPingReceived);
PingHost.Host = *IP you wish to ping*;
PingHost.StartPinging();
然后，您将编写方法来捕获上面定义的PingHost事件
private void PingHost_OnPingReceived(object DataObj, PingReceivedArgs PingReceived)
{
try
{
// code to do something when a successful ping occurrs
}
catch (Exception ex)
{
// code to do something when an exception occurrs
}
}
private void PingHost_OnPingFailed(object DataObj, PingFailedArgs PingFailed)
{
try
{
// code to do something when a ping failure occurrs
}
catch (Exception ex)
{
// code to do something when an exception occurrs
}
}
答案 3 :(得分：0)
我们的应用主要在通过无线空中卡连接的警车上运行。我们需要一种方法来确定它们是否已连接。我们编写了一个非常小的Ping.cs类，它定期ping预定的IP或计算机名称。我们解释结果消息并更改系统托盘连接图标的显示。如果你愿意，我可以发给你C＃代码。