Control.Invoke 方法

来源：互联网发布：telnet 端口原理编辑：程序博客网时间：2024/06/16 06:24

在拥有此控件的基础窗口句柄的线程上执行指定的委托。

public Object Invoke (    Delegate method)

参数

method
包含要在控件的线程上下文中调用的方法的委托。

返回值

正在被调用的委托的返回值，或者如果委托没有返回值，则为空引用（在 Visual Basic 中为 Nothing）。

// The following code assumes a 'ListBox' and a 'Button' control are added to a form, // containing a delegate which encapsulates a method that adds items to the listbox.   public class MyThreadClass   {      MyFormControl myFormControl1;      public MyThreadClass(MyFormControl myForm)      {         myFormControl1 = myForm;      }      public void Run()      {         // Execute the specified delegate on the thread that owns         // 'myFormControl1' control's underlying window handle.         myFormControl1.Invoke(myFormControl1.myDelegate);      }   }

Control.Invoke 方法 (Delegate, Object[])
在拥有控件的基础窗口句柄的线程上，用指定的参数列表执行指定委托。 
public Object Invoke (    Delegate method,    params Object[] args)
参数
method
一个方法委托，它采用的参数的数量和类型与 args 参数中所包含的相同。 
args
作为指定方法的参数传递的对象数组。如果此方法没有参数，该参数可以是 空引用（在 Visual Basic 中为 Nothing）。 
 
 
返回值
Object，它包含正被调用的委托返回值；如果该委托没有返回值，则为 空引用（在 Visual Basic 中为 Nothing）。 
using System;using System.Drawing;using System.Windows.Forms;using System.Threading;   public class MyFormControl : Form   {      public delegate void AddListItem(String myString);      public AddListItem myDelegate;      private Button myButton;      private Thread myThread;      private ListBox myListBox;      public MyFormControl()      {         myButton = new Button();         myListBox = new ListBox();         myButton.Location = new Point(72, 160);         myButton.Size = new Size(152, 32);         myButton.TabIndex = 1;         myButton.Text = "Add items in list box";         myButton.Click += new EventHandler(Button_Click);         myListBox.Location = new Point(48, 32);         myListBox.Name = "myListBox";         myListBox.Size = new Size(200, 95);         myListBox.TabIndex = 2;         ClientSize = new Size(292, 273);         Controls.AddRange(new Control[] {myListBox,myButton});         Text = " 'Control_Invoke' example ";         myDelegate = new AddListItem(AddListItemMethod);      }      static void Main()      {         MyFormControl myForm = new MyFormControl();         myForm.ShowDialog();      }      public void AddListItemMethod(String myString)      {            myListBox.Items.Add(myString);      }      private void Button_Click(object sender, EventArgs e)      {         myThread = new Thread(new ThreadStart(ThreadFunction));         myThread.Start();      }      private void ThreadFunction()      {         MyThreadClass myThreadClassObject  = new MyThreadClass(this);         myThreadClassObject.Run();      }   }   public class MyThreadClass   {      MyFormControl myFormControl1;      public MyThreadClass(MyFormControl myForm)      {         myFormControl1 = myForm;      }      String myString;      public void Run()      {         for (int i = 1; i <= 5; i++)         {            myString = "Step number " + i.ToString() + " executed";            Thread.Sleep(400);            // Execute the specified delegate on the thread that owns            // 'myFormControl1' control's underlying window handle with            // the specified list of arguments.            myFormControl1.Invoke(myFormControl1.myDelegate,                                   new Object[] {myString});         }      }   }