ThreadStart 委托

定义

命名空间:

System.Threading

程序集:

System.Threading.Thread.dll

表示在 Thread 上执行的方法。

public delegate void ThreadStart();

public delegate void ThreadStart();

type ThreadStart = delegate of unit -> unit

Public Delegate Sub ThreadStart()

示例

下面的代码示例演示用于通过实例方法和 ThreadStart 静态方法创建和使用委托的语法。

有关演示如何创建委托的另一个 ThreadStart 简单示例，请参阅 Thread.Start() 方法重载。 有关线程创建的详细信息，请参阅 在开始时间创建线程和传递数据。

using namespace System;
using namespace System::Threading;
ref class Work
{
public:
   static void DoWork()
   {
      Console::WriteLine( "Static thread procedure." );
   }

   int Data;
   void DoMoreWork()
   {
      Console::WriteLine( "Instance thread procedure. Data={0}", Data );
   }

};

int main()
{
   
   // To start a thread using an instance method for the thread 
   // procedure, specify the object as the first argument of the
   // ThreadStart constructor.
   //
   Work^ w = gcnew Work;
   w->Data = 42;
   ThreadStart^ threadDelegate = gcnew ThreadStart( w, &Work::DoMoreWork );
   Thread^ newThread = gcnew Thread( threadDelegate );
   newThread->Start();
   
   // To start a thread using a static thread procedure, specify
   // only the address of the procedure. This is a change from 
   // earlier versions of the .NET Framework, which required 
   // two arguments, the first of which was null (0).
   //
   threadDelegate = gcnew ThreadStart( &Work::DoWork );
   newThread = gcnew Thread( threadDelegate );
   newThread->Start();
}

/* This code example produces the following output (the order 
   of the lines might vary):
Static thread procedure.
Instance thread procedure. Data=42
 */

using System;
using System.Threading;

class Test
{
    static void Main() 
    {
        // To start a thread using a static thread procedure, use the
        // class name and method name when you create the ThreadStart
        // delegate. Beginning in version 2.0 of the .NET Framework,
        // it is not necessary to create a delegate explicitly. 
        // Specify the name of the method in the Thread constructor, 
        // and the compiler selects the correct delegate. For example:
        //
        // Thread newThread = new Thread(Work.DoWork);
        //
        ThreadStart threadDelegate = new ThreadStart(Work.DoWork);
        Thread newThread = new Thread(threadDelegate);
        newThread.Start();

        // To start a thread using an instance method for the thread 
        // procedure, use the instance variable and method name when 
        // you create the ThreadStart delegate. Beginning in version
        // 2.0 of the .NET Framework, the explicit delegate is not
        // required.
        //
        Work w = new Work();
        w.Data = 42;
        threadDelegate = new ThreadStart(w.DoMoreWork);
        newThread = new Thread(threadDelegate);
        newThread.Start();
    }
}

class Work 
{
    public static void DoWork() 
    {
        Console.WriteLine("Static thread procedure."); 
    }
    public int Data;
    public void DoMoreWork() 
    {
        Console.WriteLine("Instance thread procedure. Data={0}", Data); 
    }
}

/* This code example produces the following output (the order 
   of the lines might vary):
Static thread procedure.
Instance thread procedure. Data=42
 */

Imports System.Threading

Public Class Test

    <MTAThread> _
    Shared Sub Main()
        ' To start a thread using a static thread procedure, use the
        ' class name and method name when you create the ThreadStart
        ' delegate. Visual Basic expands the AddressOf expression 
        ' to the appropriate delegate creation syntax:
        '    New ThreadStart(AddressOf Work.DoWork)
        '
        Dim newThread As New Thread(AddressOf Work.DoWork)
        newThread.Start()

        ' To start a thread using an instance method for the thread 
        ' procedure, use the instance variable and method name when 
        ' you create the ThreadStart delegate. Visual Basic expands 
        ' the AddressOf expression to the appropriate delegate 
        ' creation syntax:
        '    New ThreadStart(AddressOf w.DoMoreWork)
        '
        Dim w As New Work()
        w.Data = 42
        newThread = new Thread(AddressOf w.DoMoreWork)
        newThread.Start()
    End Sub
End Class

Public Class Work 
    Public Shared Sub DoWork()
        Console.WriteLine("Static thread procedure.")
    End Sub
    Public Data As Integer
    Public Sub DoMoreWork() 
        Console.WriteLine("Instance thread procedure. Data={0}", Data) 
    End Sub
End Class

' This code example produces the following output (the order 
'   of the lines might vary):
'
'Static thread procedure.
'Instance thread procedure. Data=42

注解

创建托管线程时，在线程上执行的方法由传递给Thread构造函数的ThreadStart委托或ParameterizedThreadStart委托表示。 在调用 方法之前， Thread.Start 线程不会开始执行。 执行从 或 ParameterizedThreadStart 委托表示ThreadStart的方法的第一行开始。

注意

创建线程时， ThreadStart Visual Basic 和 C# 用户可以省略 或 ParameterizedThreadStart 委托构造函数。 在 Visual Basic 中，将 方法传递给Thread构造函数时，请使用 AddressOf 运算符;例如 Dim t As New Thread(AddressOf ThreadProc)。 在 C# 中，只需指定线程过程的名称。 编译器选择正确的委托构造函数。

对于 C++，从 .NET Framework 2.0 开始，为静态方法创建ThreadStart委托只需要一个参数：回调方法的地址，由类名限定。 在早期版本中，为静态方法创建委托时需要两个参数：零 (null) 和方法地址。 对于实例方法，所有版本都需要两个参数：实例变量和方法地址。

扩展方法

GetMethodInfo(Delegate)

获取指示指定委托表示的方法的对象。

另请参阅

• ParameterizedThreadStart
• Thread
• Start
• AppDomain
• 启动时创建线程并传递数据