C# TimerCallback　执行的方法为何无法正确改变全局变量呢？
NetStatus变量的值，按理应该是true才对的，为什么执行起来，总是false,可是Ｆ11调试时，也有时是true的，不明白这是为什么，多线程的问题吗？怎么解决呢？

代码如下：

C# code

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Threading;namespace TestConnSql{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();            wait_conn();        }        private void wait_conn()        {            bool NetStatus, net = false;            string DataS = "192.168.160.1";            int ty;            CheckIpConn conn = new CheckIpConn();            ty = conn.TT;            //net = conn.Connected;            conn.CheckIp(DataS);            //Thread.Sleep(2000);            ty = conn.TT;            NetStatus = conn.Connected;            //net = CheckIpConn.CheckIp(DataS);            // MessageBox.Show(net.ToString());            //conn.setvalue();            NetStatus = conn.Connected;            if (!NetStatus)                MessageBox.Show(conn.Connected.ToString() + ty.ToString());        }    }}

C# code

using System;using System.Collections.Generic;using System.Net;using System.Net.Sockets;using System.Threading;using System.Text;using System.Windows.Forms;namespace TestConnSql{    public class CheckIpConn    {        private int _port = 1433;        private volatile bool _connect;        private IPEndPoint _iPEndPoint;        private TcpClient _client;        private TimerCallback _timerCallBack;        private System.Threading.Timer _timer;        private int tt = 5;        public int TT        {            get { return tt; }        }        public int Port        {            get { return _port; }            set { _port = value; }        }        public bool Connected        {            get { return _connect; }        }        public void setvalue()        {            _connect = true;        }        public void CheckIp(string Ip)        {                _iPEndPoint = new IPEndPoint(IPAddress.Parse(Ip), _port);                _timerCallBack = new TimerCallback(CheckConnect);                _timer = new System.Threading.Timer(_timerCallBack, null, 10, 1000);                _timer.Dispose();                                            }        public void CheckConnect(object o)        {            try            {                _client = new TcpClient();                                _client.Connect(_iPEndPoint);                _connect = true;                this._connect = true;                tt = 50;                //MessageBox.Show("cc" + _connect);                _client.Close();            }            catch            {                _connect = false;               //MessageBox.Show("cc" + _connect);            }        }    }}

[解决办法]
conn.Connected 的值是不确定的，

加线程休眠 意思是等3秒，3秒之后获取结果

能否连上是不确定的。
[解决办法]
我一开始是假定你了解多线程的,因为你的代码里是开启了2个线程.

所以,我告诉你 conn.Connected 的值是不确定的,两个任务并行.

不通信的情况,就是不确定的.

可是后来我才发现 你不知道你的代码做了什么事

我觉得你没理解任务并行,以及当前"环境"