另一个例子:我写过拨号程序,给你例子里看看。 [StructLayout(LayoutKind.Sequential,Pack=4,CharSet=CharSet.Auto)] public struct RASDIALPARAMS { public int dwSize; [MarshalAs(UnmanagedType.ByValTStr,SizeConst=RAS_MaxEntryName + 1)] public string szEntryName; [MarshalAs(UnmanagedType.ByValTStr,SizeConst=RAS_MaxPhoneNumber + 1)] public string szPhoneNumber; [MarshalAs(UnmanagedType.ByValTStr,SizeConst=RAS_MaxCallbackNumber+ 1)] public string szCallbackNumber; [MarshalAs(UnmanagedType.ByValTStr,SizeConst=UNLEN + 1)] public string szUserName; [MarshalAs(UnmanagedType.ByValTStr,SizeConst=PWLEN + 1)] public string szPassword; [MarshalAs(UnmanagedType.ByValTStr,SizeConst=DNLEN + 1)] public string szDomain; public int dwSubEntry; public int dwCallbackId; }[DllImport("Rasapi32.dll", CharSet=CharSet.Auto)] public static extern int RasDial(int lpRasDialExtensions, string lpszPhonebook,ref RASDIALPARAMS lprasdialparams, int dwNotifierType,Callback lpvNotifier, ref int lphRasConn); private RASDIALPARAMS RasDialParams; private int Connection; [DllImport("Rasapi32.dll", CharSet=CharSet.Auto)] public static extern int RasHangUp(long lphRasConn); [StructLayout(LayoutKind.Sequential,Pack=4,CharSet=CharSet.Auto)] public struct RASCONN { public int dwSize; public int hrasconn; [MarshalAs(UnmanagedType.ByValTStr,SizeConst=RAS_MaxEntryName + 1)] public string szEntryName; [MarshalAs(UnmanagedType.ByValTStr,SizeConst=RAS_MaxDeviceType + 1)] public string szDeviceType; [MarshalAs(UnmanagedType.ByValTStr,SizeConst=RAS_MaxDeviceName + 1)] public string szDeviceName; }[DllImport("Rasapi32.dll", CharSet=CharSet.Auto)] public static extern int RasEnumConnections(ref RASCONN lprasconn,ref int lpcb,ref int lpcConnections);public RasManager() { Connection = 0; RasDialParams = new RASDIALPARAMS(); RasDialParams.dwSize = Marshal.SizeOf(RasDialParams); }下面是调用方法 Connection = 0; RasDialParams.szEntryName += "\0"; RasDialParams.szUserName += "\0"; RasDialParams.szPassword += "\0"; int result = RasDial(0,null,ref RasDialParams,0,null,ref Connection);
System.Diagnostics.Process proIP=new System.Diagnostics.Process();
proIP.StartInfo.FileName="cmd.exe";
proIP.StartInfo.UseShellExecute = false;
proIP.StartInfo.RedirectStandardInput = true;
proIP.StartInfo.RedirectStandardOutput = true;
proIP.StartInfo.RedirectStandardError = true;
proIP.StartInfo.CreateNoWindow = true;//不显示cmd窗口
proIP.Start();
proIP.StandardInput.WriteLine("ping "+this.txtIP.Text.Trim());
proIP.StandardInput.WriteLine("exit");
string strResult=proIP.StandardOutput.ReadToEnd();
if(strResult.IndexOf("(0% loss)")!=-1)
this.txtShow.Text="Ping 通了!";
else if(strResult.IndexOf("(100% loss)")!=-1)
this.txtShow.Text="无法 Ping 通!";
else
this.txtShow.Text="数据有丢失!";
proIP.Close();再来看看用win32 API函数的做法:
要用的函数:InternetGetConnectedState
函数原形:BOOL InternetGetConnectedState(LPDWORD lpdwFlags,DWORD dwReserved);
参数lpdwFlags返回当前网络状态,参数dwReserved依然是保留参数,设置为0即可。
INTERNET_CONNECTION_MODEM 通过调治解调器连接网络
INTERNET_CONNECTION_LAN 通过局域网连接网络
这个函数的功能是很强的。它可以:
1. 判断网络连接是通过网卡还是通过调治解调器
2. 是否通过代理上网
3. 判断连接是On Line还是Off Line
4. 判断是否安装“拨号网络服务”
5. 判断调治解调器是否正在使用
这个win32 API在系统system32文件夹中winInet.dll中
使用这个判断的话,需要在类中这样写:
private const int INTERNET_CONNECTION_MODEM = 1;
private const int INTERNET_CONNECTION_LAN = 2;
[DllImport("winInet.dll")]
private static extern bool InternetGetConnectedState(
ref int dwFlag,
int dwReserved
);
//调用的方法(Winform为例,放一个按钮,单击即可):
private void button1_Click(object sender, System.EventArgs e){
System.Int32 dwFlag = new int();
if(!InternetGetConnectedState(ref dwFlag, 0))
MessageBox.Show("未连网!");
else
if((dwFlag & INTERNET_CONNECTION_MODEM)!=0)
MessageBox.Show("采用调治解调器上网。");
else
if((dwFlag & INTERNET_CONNECTION_LAN)!=0)
MessageBox.Show("采用网卡上网。");
}
[StructLayout(LayoutKind.Sequential,Pack=4,CharSet=CharSet.Auto)]
public struct RASDIALPARAMS
{
public int dwSize;
[MarshalAs(UnmanagedType.ByValTStr,SizeConst=RAS_MaxEntryName + 1)]
public string szEntryName;
[MarshalAs(UnmanagedType.ByValTStr,SizeConst=RAS_MaxPhoneNumber + 1)]
public string szPhoneNumber;
[MarshalAs(UnmanagedType.ByValTStr,SizeConst=RAS_MaxCallbackNumber+ 1)]
public string szCallbackNumber;
[MarshalAs(UnmanagedType.ByValTStr,SizeConst=UNLEN + 1)]
public string szUserName;
[MarshalAs(UnmanagedType.ByValTStr,SizeConst=PWLEN + 1)]
public string szPassword;
[MarshalAs(UnmanagedType.ByValTStr,SizeConst=DNLEN + 1)]
public string szDomain;
public int dwSubEntry;
public int dwCallbackId;
}[DllImport("Rasapi32.dll", CharSet=CharSet.Auto)]
public static extern int RasDial(int lpRasDialExtensions, string lpszPhonebook,ref RASDIALPARAMS lprasdialparams, int dwNotifierType,Callback lpvNotifier, ref int lphRasConn);
private RASDIALPARAMS RasDialParams;
private int Connection;
[DllImport("Rasapi32.dll", CharSet=CharSet.Auto)]
public static extern int RasHangUp(long lphRasConn);
[StructLayout(LayoutKind.Sequential,Pack=4,CharSet=CharSet.Auto)]
public struct RASCONN
{
public int dwSize;
public int hrasconn;
[MarshalAs(UnmanagedType.ByValTStr,SizeConst=RAS_MaxEntryName + 1)]
public string szEntryName;
[MarshalAs(UnmanagedType.ByValTStr,SizeConst=RAS_MaxDeviceType + 1)]
public string szDeviceType;
[MarshalAs(UnmanagedType.ByValTStr,SizeConst=RAS_MaxDeviceName + 1)]
public string szDeviceName;
}[DllImport("Rasapi32.dll", CharSet=CharSet.Auto)]
public static extern int RasEnumConnections(ref RASCONN lprasconn,ref int lpcb,ref int lpcConnections);public RasManager()
{
Connection = 0;
RasDialParams = new RASDIALPARAMS();
RasDialParams.dwSize = Marshal.SizeOf(RasDialParams);
}下面是调用方法
Connection = 0;
RasDialParams.szEntryName += "\0";
RasDialParams.szUserName += "\0";
RasDialParams.szPassword += "\0";
int result = RasDial(0,null,ref RasDialParams,0,null,ref Connection);