跨線程調用控件

在VS 2005  中考慮到線程的安全性，不允許跨線程調用控件!  為了解決這一問題

 1. 將Control 的 CheckForIllegalCrossThreadCalls 屬性設置為假, 不去捕獲錯誤線程的調用，但這種做法是不安全的！

2.使用委托異步調用

見代碼:

 

 

using System;
using System.Collections.Generic;
using System.Text;
using System.Threading;
using System.Windows.Forms;
namespace TabSelect
...{
    class MyThread
    ...{
        public delegate void SetLabelText(string text);   //定義委托
        Control  control;

        Thread thread;
        ThreadStart start;
        int num2;

        構造方法，初始化線程,以及要改變屬性的控件#region  構造方法，初始化線程,以及要改變屬性的控件
        public MyThread(Control control,int  num)
        ...{
            this.control = control;
            start = new ThreadStart(BuildNum2);   //訂閱線程要執行的代碼
            this.num2 = num;
            thread = new Thread(start);

            thread.Start();
        }
        #endregion 

        線程中需要執行的方法  通過設置Control 屬性，指示是否捕獲錯誤線程的調用#region 線程中需要執行的方法  通過設置Control 屬性，指示是否捕獲錯誤線程的調用
        public void BuildNum()   
        ...{     
             Random random = new Random(num2);
             Control.CheckForIllegalCrossThreadCalls = false;

             do
             ...{
                 int num = random.Next(0, 10);
                 control.Text = num.ToString();
                 Thread.Sleep(100);
             } while (true);

         }
        #endregion 

        方法二，使用委托異步調用#region  方法二，使用委托異步調用
         public void BuildNum2()  
        ...{
            Random myRand = new Random(num2);

            while (true)
            ...{
                SetText(myRand.Next(0, 10).ToString());
                Thread.Sleep(100);
            }
        }
           #endregion


        改變UI 線程的控件屬性#region 改變UI 線程的控件屬性
        public void SetText(string  str)
        ...{
            if (control.InvokeRequired)
            ...{
                SetLabelText  setLableText  = new SetLabelText(SetText);
                control.Invoke(setLableText, new object[] ...{ str});
            }
            else
            ...{
                control.Text = str;
            }
        }
        #endregion


        public void Kill()
        ...{
            thread.Abort();

        }
    }
}

 

界面

 

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Threading;

namespace TabSelect
...{
    public partial class Form2 : Form
    ...{

        Point myPoint;
        private bool isMouseDown;
        private bool isStart = true;

        MyThread m;
        MyThread m2;
        MyThread m3;
        public Form2()
        ...{
            InitializeComponent();
        }

        private void label4_Click(object sender, EventArgs e)
        ...{
            this.Close();

            Application.Exit();
         
        }

       

        private void Form2_MouseDown(object sender, MouseEventArgs e)
        ...{
            if (e.Button == MouseButtons.Left)
      &    ...{
                myPoint = new Point(-e.X,-e.Y);
                isMouseDown = true;
            }
        }

        private void Form2_MouseMove(object sender, MouseEventArgs e)
        ...{
                if (isMouseDown == true)
                ...{
                    Point newPoint = Control.MousePosition;
                    newPoint.Offset( myPoint.X,myPoint.Y);
                    this.Location = newPoint;
                }    
        }

        private void Form2_MouseUp(object sender, MouseEventArgs e)
        ...{
            if (e.Button == MouseButtons.Left)
            ...{
                isMouseDown = false;
            }
        }

        private void Form2_Load(object sender, EventArgs e)
        ...{
          
        }

        private void timer1_Tick(object sender, EventArgs e)
        ...{
            Random myRandom = new Random();

            label1.Text = myRandom.Next(0, 10).ToString();
        }

        private void button1_Click(object sender, EventArgs e)
        ...{
            if (isStart == true)
            ...{
                  m = new MyThread(label1,1000);
                  m2 = new MyThread(label2,1111);
                  m3 = new MyThread(label3, 2222);
               
                  isStart = false;
                  button1.Text = "結束";
            }
            else
            ...{
                m.Kill();
                m2.Kill();
                m3.Kill();
                isStart = true;

                button1.Text = "開始";
            }
        }
    }
}