线程间操作无效: 从不是创建控件的线程访问它. 

 1 using System;
 2 using System.Collections.Generic;
 3 using System.ComponentModel;
 4 using System.Data;
 5 using System.Drawing;
 6 using System.Linq;
 7 using System.Text;
 8 using System.Windows.Forms;
 9 using System.Threading;
10 
11 namespace LoginIn
12 {
13     public partial class Form1 : Form
14     {
15         delegate void MyDelegate(string name, string code);
16         delegate void SetTipDelegate(string tip);
17         public Form1()
18         {
19             InitializeComponent();
20         }
21 
22         private void button1_Click(object sender, EventArgs e)
23         {
24             string name = txtName.Text;
25             string code = txtCode.Text;
26             //调用委托，用新线程校验用户名、密码
27             MyDelegate myDelegate = new MyDelegate(CheckUser);
28             myDelegate.BeginInvoke(name, code, null, null);
29         }
30 
31         void CheckUser(string name, string code)
32         {
33             Thread.Sleep(2000);
34             if (name == "1" && code == "1")
35             {
36                 SetTip("成功");
37             }
38             else
39             {
40                 SetTip("失败");
41             }
42         }
43 
44         void SetTip(string tip)
45         {
46             //是否调用Invoke方法
47             if (lbTip.InvokeRequired)
48             //if(!从创建控件“lbTip”的线程访问它)
49             {
50                 //调用委托
51                 SetTipDelegate myDelegate = new SetTipDelegate(SetTip);
52                 Invoke(myDelegate, tip);
53             }
54             else
55             {
56                 lbTip.Text = tip;
57             }
58         }
59 
60         private void timer1_Tick(object sender, EventArgs e)
61         {
62             button1.Text = DateTime.Now.ToString();
63         }
64     }
65 }

 2015年8月3日 16:49:27，更新简写版

 1         protected void button1_Click(object sender,EventArgs e)
 2         {
 3             string userName = txtName.Text;
 4             string userCode = txtCode.Text;
 5             
 6             Func<string ,string ,string> d1 = (name, code) =>           
 7                  (name == "1" && code == "1") ? "成功" : "失败";                            
 8                         
 9             d1.BeginInvoke(userName,userCode,ar=>
10                            {
11                                string result= d1.EndInvoke(ar);
12                                Action<string> action1=data=>label1.Text=data;
13                                Invoke(action1,result);
14                            },
15                            null);
16         }

 

posted @ 2014-05-23 15:07  David Huang  阅读(736)  评论(0)  编辑  收藏  举报