C# 判断是否联网
public static class Internet { [DllImport("winInet.dll")] private static extern bool InternetGetConnectedState(ref int dwFlag, int dwReserved); /// <summary> /// 返回网络状态 /// </summary> public static bool Status { get { Int32 dwFlag = new int(); if (!InternetGetConnectedState(ref dwFlag, 0)) { return false; } else { return true; } } } }