怎么判断Winform程序是否实时连接数据库(网络连接),断网时程序暂停执行,连上后手动操作

Question

怎么判断Winform程序是否实时连接数据库(网络连接),断网时程序暂停执行,连上后手动操作因为客户需要有无线网络死角的时候,操作时,程序不死掉(可以对前台TRY_CATCH..弹出MSG,然后RETURN,但修改程序量太大)请教是否有其它方法.
谢谢

Answer 1

同意楼上的，做个定时服务，总在检测Connection状态，如果失败进行处理程序。

Answer 2

给你个代码。。是判断网络链接状态的。（调用win系统内部cmd.exe来判断，你可以吧网址给改了）用个Timer组件定时判断 //判断网络是否通畅
        private void CmdPing(string strIp)
        {
            Process p = new Process();
            p.StartInfo.FileName = "cmd.exe";
            //用true试试
            p.StartInfo.UseShellExecute = false;
            p.StartInfo.RedirectStandardError = true;
            p.StartInfo.RedirectStandardInput = true;
            p.StartInfo.RedirectStandardOutput = true;
            p.StartInfo.CreateNoWindow = true;            p.Start();
            p.StandardInput.WriteLine("ping -n 1 " + strIp);
            p.StandardInput.WriteLine("exit");
            string strRst = p.StandardOutput.ReadToEnd();
            if (strRst.IndexOf("(0% loss)") != -1)
            {
                tbTitle.BackColor = Color.GreenYellow;
                tbTitle.Refresh();
            }
            else if (strRst.IndexOf("Destination host unreachable") != -1)
            {
                tbTitle.BackColor = Color.Red;
                tbTitle.Refresh();
            }
            else if (strRst.IndexOf("Request timed out") != -1)
            {
                tbTitle.BackColor = Color.Red;
                tbTitle.Refresh();
            }
            else if (strRst.IndexOf("Unknown host") != -1)
            {
                tbTitle.BackColor = Color.Red;
                tbTitle.Refresh();
            }
            else
            {
                tbTitle.BackColor = Color.Red;
                tbTitle.Refresh();
            }
            p.Close();
        } //网路情况
        private void button15_Click(object sender, EventArgs e)
        {
            CmdPing("www.meinvtu8.com");
        }

Answer 3

定时判断网络是否连接。没有连接提示用户
using System.Runtime.InteropServices;
[DllImport("wininet.dll")]
        private extern static bool InternetGetConnectedState(out int connectionDescription, int reservedValue);
private static bool IsConnected()
        {
            int I = 0;
            bool state = InternetGetConnectedState(out I, 0);
            return state;
        }
        static void Main(string[] args)
        {
            Console.WriteLine(IsConnected().ToString());
        }
或用ping

Answer 4

 public String IP;
        [System.Runtime.InteropServices.DllImport("wininet.dll")]
        private extern static bool InternetGetConnectedState(out int Description, int ReservedValue);        public static bool IsConnectedByLAN()
        {
            int Desc = 0;
            return InternetGetConnectedState(out Desc, 0);
        }
        public static bool isConnectToInternet()
        {
            Ping ping = new Ping();
            PingOptions options = new PingOptions();
            options.DontFragment = true;
            string data = "abcdefghijklmnopqrstuvwxy123456";
            byte[] buff = Encoding.ASCII.GetBytes(data);
            PingReply pingReply = ping.Send("www.baidu.com", 200, buff, options);
            if (pingReply.Status == IPStatus.Success)
            {
                return true;
            }
            else { return false; }
        }
        public static bool isConnectToServer(string ip)
        {
            Ping ping = new Ping();
            PingOptions options = new PingOptions();
            options.DontFragment = true;
            string data = "abcdefghijklmnopqrstuvwxy123456";
            byte[] buff = Encoding.ASCII.GetBytes(data);
            PingReply pingReply = ping.Send(ip, 200, buff, options);
            if (pingReply.Status == IPStatus.Success)
            {
                return true;
            }
            else { return false; }
        }
        public  static string getIP()
        {
            try
            {
                string strUrl = "http://www.ip138.com/ip2city.asp"; //获得IP的网址了                Uri uri = new Uri(strUrl);
                System.Net.WebRequest wr = System.Net.WebRequest.Create(uri);
                System.IO.Stream s = wr.GetResponse().GetResponseStream();
                System.IO.StreamReader sr = new System.IO.StreamReader(s, Encoding.Default);
                string all = sr.ReadToEnd(); //读取网站的数据                int i = all.IndexOf("[") + 1;
                string tempip = all.Substring(i, 15);
                string ip = tempip.Replace("]", "").Replace(" ", "");//找出i
                return ip;            }
            catch (Exception ex)
            {
                return "没有找到IP";
            }
        }