AsyncResult 类
定义
封装对委托的异步操作的结果。Encapsulates the results of an asynchronous operation on a delegate.
public ref class AsyncResult : IAsyncResult, System::Runtime::Remoting::Messaging::IMessageSink
public class AsyncResult : IAsyncResult, System.Runtime.Remoting.Messaging.IMessageSink
[System.Runtime.InteropServices.ComVisible(true)]
public class AsyncResult : IAsyncResult, System.Runtime.Remoting.Messaging.IMessageSink
type AsyncResult = class
interface IAsyncResult
interface IMessageSink
[<System.Runtime.InteropServices.ComVisible(true)>]
type AsyncResult = class
interface IAsyncResult
interface IMessageSink
Public Class AsyncResult
Implements IAsyncResult, IMessageSink
- 继承
-
AsyncResult
- 属性
- 实现
示例
下面的示例演示如何使用 AsyncWaitHandle 属性获取 WaitHandle ,并演示如何等待异步调用委托。The following example demonstrates how to use the AsyncWaitHandle property to get a WaitHandle, and how to wait for an asynchronous call on a delegate. 当异步调用完成时 WaitHandle 会收到信号,而你可以通过调用 WaitOne 方法来等待它。The WaitHandle is signaled when the asynchronous call completes, and you can wait for it by calling the WaitOne method.
该示例由两个类组成,该类包含异步调用的方法,以及包含 Main 进行调用的方法的类。The example consists of two classes, the class that contains the method which is called asynchronously, and the class that contains the Main method that makes the call.
有关使用委托异步调用方法的详细信息和示例,请参阅 异步调用同步方法。For more information and more examples of calling methods asynchronously by using delegates, see Calling Synchronous Methods Asynchronously.
using namespace System;
using namespace System::Threading;
using namespace System::Runtime::InteropServices;
namespace Examples {
namespace AdvancedProgramming {
namespace AsynchronousOperations
{
public ref class AsyncDemo
{
public:
// The method to be executed asynchronously.
String^ TestMethod(int callDuration, [OutAttribute] int% threadId)
{
Console::WriteLine("Test method begins.");
Thread::Sleep(callDuration);
threadId = Thread::CurrentThread->ManagedThreadId;
return String::Format("My call time was {0}.", callDuration);
}
};
// The delegate must have the same signature as the method
// it will call asynchronously.
public delegate String^ AsyncMethodCaller(int callDuration, [OutAttribute] int% threadId);
}}}
using System;
using System.Threading;
namespace Examples.AdvancedProgramming.AsynchronousOperations
{
public class AsyncDemo
{
// The method to be executed asynchronously.
public string TestMethod(int callDuration, out int threadId)
{
Console.WriteLine("Test method begins.");
Thread.Sleep(callDuration);
threadId = Thread.CurrentThread.ManagedThreadId;
return String.Format("My call time was {0}.", callDuration.ToString());
}
}
// The delegate must have the same signature as the method
// it will call asynchronously.
public delegate string AsyncMethodCaller(int callDuration, out int threadId);
}
Imports System.Threading
Imports System.Runtime.InteropServices
Namespace Examples.AdvancedProgramming.AsynchronousOperations
Public Class AsyncDemo
' The method to be executed asynchronously.
Public Function TestMethod(ByVal callDuration As Integer, _
<Out> ByRef threadId As Integer) As String
Console.WriteLine("Test method begins.")
Thread.Sleep(callDuration)
threadId = Thread.CurrentThread.ManagedThreadId()
return String.Format("My call time was {0}.", callDuration.ToString())
End Function
End Class
' The delegate must have the same signature as the method
' it will call asynchronously.
Public Delegate Function AsyncMethodCaller(ByVal callDuration As Integer, _
<Out> ByRef threadId As Integer) As String
End Namespace
#using <TestMethod.dll>
using namespace System;
using namespace System::Threading;
using namespace Examples::AdvancedProgramming::AsynchronousOperations;
void main()
{
// The asynchronous method puts the thread id here.
int threadId;
// Create an instance of the test class.
AsyncDemo^ ad = gcnew AsyncDemo();
// Create the delegate.
AsyncMethodCaller^ caller = gcnew AsyncMethodCaller(ad, &AsyncDemo::TestMethod);
// Initiate the asychronous call.
IAsyncResult^ result = caller->BeginInvoke(3000,
threadId, nullptr, nullptr);
Thread::Sleep(0);
Console::WriteLine("Main thread {0} does some work.",
Thread::CurrentThread->ManagedThreadId);
// Wait for the WaitHandle to become signaled.
result->AsyncWaitHandle->WaitOne();
// Perform additional processing here.
// Call EndInvoke to retrieve the results.
String^ returnValue = caller->EndInvoke(threadId, result);
// Close the wait handle.
result->AsyncWaitHandle->Close();
Console::WriteLine("The call executed on thread {0}, with return value \"{1}\".",
threadId, returnValue);
}
/* This example produces output similar to the following:
Main thread 1 does some work.
Test method begins.
The call executed on thread 3, with return value "My call time was 3000.".
*/
using System;
using System.Threading;
namespace Examples.AdvancedProgramming.AsynchronousOperations
{
public class AsyncMain
{
static void Main()
{
// The asynchronous method puts the thread id here.
int threadId;
// Create an instance of the test class.
AsyncDemo ad = new AsyncDemo();
// Create the delegate.
AsyncMethodCaller caller = new AsyncMethodCaller(ad.TestMethod);
// Initiate the asychronous call.
IAsyncResult result = caller.BeginInvoke(3000,
out threadId, null, null);
Thread.Sleep(0);
Console.WriteLine("Main thread {0} does some work.",
Thread.CurrentThread.ManagedThreadId);
// Wait for the WaitHandle to become signaled.
result.AsyncWaitHandle.WaitOne();
// Perform additional processing here.
// Call EndInvoke to retrieve the results.
string returnValue = caller.EndInvoke(out threadId, result);
// Close the wait handle.
result.AsyncWaitHandle.Close();
Console.WriteLine("The call executed on thread {0}, with return value \"{1}\".",
threadId, returnValue);
}
}
}
/* This example produces output similar to the following:
Main thread 1 does some work.
Test method begins.
The call executed on thread 3, with return value "My call time was 3000.".
*/
Imports System.Threading
Imports System.Runtime.InteropServices
Namespace Examples.AdvancedProgramming.AsynchronousOperations
Public Class AsyncMain
Shared Sub Main()
' The asynchronous method puts the thread id here.
Dim threadId As Integer
' Create an instance of the test class.
Dim ad As New AsyncDemo()
' Create the delegate.
Dim caller As New AsyncMethodCaller(AddressOf ad.TestMethod)
' Initiate the asynchronous call.
Dim result As IAsyncResult = caller.BeginInvoke(3000, _
threadId, Nothing, Nothing)
Thread.Sleep(0)
Console.WriteLine("Main thread {0} does some work.", _
Thread.CurrentThread.ManagedThreadId)
' Perform additional processing here and then
' wait for the WaitHandle to be signaled.
result.AsyncWaitHandle.WaitOne()
' Call EndInvoke to retrieve the results.
Dim returnValue As String = caller.EndInvoke(threadId, result)
' Close the wait handle.
result.AsyncWaitHandle.Close()
Console.WriteLine("The call executed on thread {0}, with return value ""{1}"".", _
threadId, returnValue)
End Sub
End Class
End Namespace
'This example produces output similar to the following:
'
'Main thread 1 does some work.
'Test method begins.
'The call executed on thread 3, with return value "My call time was 3000.".
注解
AsyncResult类与使用委托进行的异步方法调用结合使用。The AsyncResult class is used in conjunction with asynchronous method calls made using delegates. IAsyncResult从委托的方法返回的 BeginInvoke 可以强制转换为 AsyncResult 。The IAsyncResult returned from the delegate's BeginInvoke method can be cast to an AsyncResult. AsyncResult具有 AsyncDelegate 属性,该属性保存在其上调用异步调用的委托对象。The AsyncResult has the AsyncDelegate property that holds the delegate object on which the asynchronous call was invoked.
有关 BeginInvoke 使用委托的和异步调用的详细信息,请参阅 使用委托进行异步编程。For more information about BeginInvoke and asynchronous calls using delegates, see Asynchronous Programming Using Delegates.
属性
| AsyncDelegate |
获取在其上调用异步调用的委托对象。Gets the delegate object on which the asynchronous call was invoked. |
| AsyncState |
获取作为 |
| AsyncWaitHandle |
获取封装 Win32 同步句柄并允许实现各种同步方案的 WaitHandle。Gets a WaitHandle that encapsulates Win32 synchronization handles, and allows the implementation of various synchronization schemes. |
| CompletedSynchronously |
获取一个值,该值指示 |
| EndInvokeCalled |
获取或设置一个值,该值指示是否已在当前 AsyncResult 上调用 |
| IsCompleted |
获取一个值,该值指示服务器是否已完成该调用。Gets a value indicating whether the server has completed the call. |
| NextSink |
获取接收器链中的下一个消息接收器。Gets the next message sink in the sink chain. |
方法
| AsyncProcessMessage(IMessage, IMessageSink) |
实现 IMessageSink 接口。Implements the IMessageSink interface. |
| Equals(Object) |
确定指定对象是否等于当前对象。Determines whether the specified object is equal to the current object. (继承自 Object) |
| GetHashCode() |
作为默认哈希函数。Serves as the default hash function. (继承自 Object) |
| GetReplyMessage() |
获取异步调用的响应消息。Gets the response message for the asynchronous call. |
| GetType() |
获取当前实例的 Type。Gets the Type of the current instance. (继承自 Object) |
| MemberwiseClone() |
创建当前 Object 的浅表副本。Creates a shallow copy of the current Object. (继承自 Object) |
| SetMessageCtrl(IMessageCtrl) |
为当前远程方法调用设置一个 IMessageCtrl,这为在调度异步消息后控制异步消息提供了一种方法。Sets an IMessageCtrl for the current remote method call, which provides a way to control asynchronous messages after they have been dispatched. |
| SyncProcessMessage(IMessage) |
异步处理远程对象上的方法调用返回的响应消息。Synchronously processes a response message returned by a method call on a remote object. |
| ToString() |
返回表示当前对象的字符串。Returns a string that represents the current object. (继承自 Object) |