一个异步执行的小例子

我用的visual studio 2008

winform界面初始化类

partial class BeginInvoke
{
/// <summary>
/// Required designer variable.
/// </summary>
private System.ComponentModel.IContainer components = null;

/// <summary>
/// Clean up any resources being used.
/// </summary>
/// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}

#region Windows Form Designer generated code

/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
this.button1 = new System.Windows.Forms.Button();
this.textBox1 = new System.Windows.Forms.TextBox();
this.label1 = new System.Windows.Forms.Label();
this.SuspendLayout();
//
// button1
//
this.button1.Location = new System.Drawing.Point(254, 274);
this.button1.Name = "button1";
this.button1.Size = new System.Drawing.Size(75, 23);
this.button1.TabIndex = 0;
this.button1.Text = "执行";
this.button1.UseVisualStyleBackColor = true;
this.button1.Click += new System.EventHandler(this.button1_Click);
//
// textBox1
//
this.textBox1.Location = new System.Drawing.Point(254, 128);
this.textBox1.Name = "textBox1";
this.textBox1.Size = new System.Drawing.Size(100, 21);
this.textBox1.TabIndex = 1;
//
// label1
//
this.label1.AutoSize = true;
this.label1.Location = new System.Drawing.Point(183, 131);
this.label1.Name = "label1";
this.label1.Size = new System.Drawing.Size(65, 12);
this.label1.TabIndex = 2;
this.label1.Text = "输入个数：";
//
// BeginInvoke
//
this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
this.ClientSize = new System.Drawing.Size(735, 459);
this.Controls.Add(this.label1);
this.Controls.Add(this.textBox1);
this.Controls.Add(this.button1);
this.Name = "BeginInvoke";
this.Text = "BeginInvoke";
this.ResumeLayout(false);
this.PerformLayout();

}

#endregion

private System.Windows.Forms.Button button1;
private System.Windows.Forms.TextBox textBox1;
private System.Windows.Forms.Label label1;
}

包括的事件处理类

public partial class BeginInvoke : Form
{
public delegate int ProcessDel(int a);
public BeginInvoke()
{
InitializeComponent();
}
private int Process(int a)
{
Thread.Sleep(10000);
return a * a;
}
private void button1_Click(object sender, EventArgs e)
{
int count = int.Parse(this.textBox1.Text.Trim());
ProcessDel pd = new ProcessDel(Process);
Myobject mobject=new Myobject();
mobject.message="成功";
mobject.pd=pd;
pd.BeginInvoke(count, MethodComplete, mobject);
}
private void MethodComplete(IAsyncResult asycresult)
{
ProcessDel pd = ((Myobject)asycresult.AsyncState).pd as ProcessDel;
string message = ((Myobject)asycresult.AsyncState).message;
int result=pd.EndInvoke(asycresult);
MessageBox.Show("处理"+message+",处理结果："+result);
}
}
public class Myobject
{
public Delegate pd;
public string message;
}

下面是界面



上面实现的功能就是模拟一个长时间处理过程Process(int a)，输入一个参数，然后点击按钮进行处理，执行异步操作，最后把处理结果返回给用户。此程序主要用到了委托和委托异步执行。理解delege。begininvoke的用法，尤其是最后一个参数和倒数第二个参数，一个是object类型，一个是回调过程名，回调过程顾名思义就是异步执行完毕后执行的过程。在回调过程里，我们把执行后的结果通过object中包含的delegate实例通过endinvoke（asycresult）进行获取，把要提示的“成功”字符串包含在object里头传给回调过程，通过拆箱操作获取。最后把结果和传递的字符串通过messagebox提示给用户。这样既防止了界面假死也完成了程序功能。了解更多异步执行或者线程只是请参见网址/article/4740814.html