能不能判断用户是否已经连上Internet(winform)

Question

如题。先在此谢谢高手赐教

Answer 1

http://www.c-sharpcorner.com/Code/2003/Aug/CheckInternetConnection.asp  

Answer 2

WMI:
public string NetStatus()
                {
                        ManagementObjectCollection objects;
                        string status = "";
                        ManagementObjectSearcher searcher = new ManagementObjectSearcher();
                        searcher.Query.QueryString = "Select * From Win32_NetworkAdapter ";
                        objects = searcher.Get();
                        foreach(ManagementObject obj in objects)
                        {
                                foreach(PropertyData p in obj.Properties)
                                {
                                        if(p.Name.Equals("NetConnectionStatus"))
                                        {
                                                if(p.Value!=null)
                                                {
                                                        status = p.Value.ToString();
                                                }
                                        }
                                }
                        }
                        switch(status)
                        {
                                case "0":
                                        return "Disconnected";
                                case "1":
                                        return "Connecting ...";
                                case "2":
                                        return "Connected";
                                case "3":
                                        return "Disconnecting ...";
                                case "4":
                                        return "Hardware not present";
                                case "5":
                                        return "Hardware disabled";
                                case "6":
                                        return "Hardware malfunction";
                                case "7":
                                        return "Media disconnected";
                                case "8":
                                        return "Authenticating";
                                case "9":
                                        return "Authentication succeeded";
                                case "10":
                                        return "Authentication failed";
                                default:
                                        return "";
                        }
                }

Answer 3

public class InternetCS 
{ 
 
    //Creating the extern function 
    [DllImport("wininet.dll")] 
    private extern static bool InternetGetConnectedState(int Description,int ReservedValue); 
 
    //Creating a function that uses the API function 
    public static bool IsConnectedToInternet() 
    { 
        int Desc=0; 
        return InternetGetConnectedState(Desc,0) ; 
    } 
 
} 
判断是否已经连网

Answer 4

提供一个最简单的方法
在webservice中写一个web方法
[WebMethod]
public bool CheckState()
{
   return true;
}
本地添加WEB引用
调用bool State=false;
 try
{
    State=WebService.CheckState();
}
catch
{}
如果State为true则在线！！反之就不在线！

Answer 5

NewBo(^_^) 
你的方法还是他麻烦public class InternetCS 
{ 
 
    //Creating the extern function 
    [DllImport("wininet.dll")] 
    private extern static bool InternetGetConnectedState(int Description,int ReservedValue); 
 
    //Creating a function that uses the API function 
    public static bool IsConnectedToInternet() 
    { 
        int Desc=0; 
        return InternetGetConnectedState(Desc,0) ; 
    } 
 
} 这个方法简单，哈哈
谢谢各位了