SoapHttpClientProtocol.BeginInvoke 方法

protected:
 IAsyncResult ^ BeginInvoke(System::String ^ methodName, cli::array <System::Object ^> ^ parameters, AsyncCallback ^ callback, System::Object ^ asyncState);

protected IAsyncResult BeginInvoke(string methodName, object[] parameters, AsyncCallback callback, object asyncState);

member this.BeginInvoke : string * obj[] * AsyncCallback * obj -> IAsyncResult

Protected Function BeginInvoke (methodName As String, parameters As Object(), callback As AsyncCallback, asyncState As Object) As IAsyncResult

IAsyncResult，传递给 EndInvoke(IAsyncResult) 方法以从远程方法调用中获取返回值。

下面的代码示例是由 XML Web 服务的 Web 服务描述语言工具 (Wsdl.exe) Math 生成的代理类。 BeginAdd在代理类的 方法中BeginInvoke， 方法正在启动对 XML Web 服务方法的Add异步调用。

#using <System.Web.Services.dll>
#using <System.Xml.dll>
#using <System.dll>

using namespace System::Diagnostics;
using namespace System::Xml::Serialization;
using namespace System;
using namespace System::Web::Services::Protocols;
using namespace System::Web::Services;

namespace MyMath
{

   [System::Web::Services::WebServiceBindingAttribute(Name="MyMathSoap",Namespace="http://www.contoso.com/")]
   public ref class MyMath: public System::Web::Services::Protocols::SoapHttpClientProtocol
   {
   public:

      [System::Diagnostics::DebuggerStepThroughAttribute]
      MyMath()
      {
         this->Url = "http://www.contoso.com/math.asmx";
      }


      [System::Diagnostics::DebuggerStepThroughAttribute]
      [System::Web::Services::Protocols::SoapDocumentMethodAttribute("http://www.contoso.com/Add",
      RequestNamespace="http://www.contoso.com/",ResponseNamespace="http://www.contoso.com/",
      Use=System::Web::Services::Description::SoapBindingUse::Literal,
      ParameterStyle=System::Web::Services::Protocols::SoapParameterStyle::Wrapped)]
      int Add( int num1, int num2 )
      {
         array<Object^>^temp1 = {num1,num2};
         array<Object^>^results = this->Invoke( "Add", temp1 );
         return  *dynamic_cast<int^>(results[ 0 ]);
      }


      [System::Diagnostics::DebuggerStepThroughAttribute]
      System::IAsyncResult^ BeginAdd( int num1, int num2, System::AsyncCallback^ callback, Object^ asyncState )
      {
         array<Object^>^temp2 = {num1,num2};
         return this->BeginInvoke( "Add", temp2, callback, asyncState );
      }


      [System::Diagnostics::DebuggerStepThroughAttribute]
      int EndAdd( System::IAsyncResult^ asyncResult )
      {
         array<Object^>^results = this->EndInvoke( asyncResult );
         return  *dynamic_cast<int^>(results[ 0 ]);
      }

   };

}

namespace MyMath {
    using System.Diagnostics;
    using System.Xml.Serialization;
    using System;
    using System.Web.Services.Protocols;
    using System.Web.Services;

    [System.Web.Services.WebServiceBindingAttribute(Name="MyMathSoap", Namespace="http://www.contoso.com/")]
    public class MyMath : System.Web.Services.Protocols.SoapHttpClientProtocol {

        [System.Diagnostics.DebuggerStepThroughAttribute()]
        public MyMath() {
            this.Url = "http://www.contoso.com/math.asmx";
        }

        [System.Diagnostics.DebuggerStepThroughAttribute()]
        [System.Web.Services.Protocols.SoapDocumentMethodAttribute("http://www.contoso.com/Add", RequestNamespace="http://www.contoso.com/", ResponseNamespace="http://www.contoso.com/", Use=System.Web.Services.Description.SoapBindingUse.Literal, ParameterStyle=System.Web.Services.Protocols.SoapParameterStyle.Wrapped)]
        public int Add(int num1, int num2) {
            object[] results = this.Invoke("Add", new object[] {num1,
                        num2});
            return ((int)(results[0]));
        }

        [System.Diagnostics.DebuggerStepThroughAttribute()]
        public System.IAsyncResult BeginAdd(int num1, int num2, System.AsyncCallback callback, object asyncState) {
            return this.BeginInvoke("Add", new object[] {num1,
                        num2}, callback, asyncState);
        }

        [System.Diagnostics.DebuggerStepThroughAttribute()]
        public int EndAdd(System.IAsyncResult asyncResult) {
            object[] results = this.EndInvoke(asyncResult);
            return ((int)(results[0]));
        }
    }
}

Option Strict On
Option Explicit On

Imports System.Diagnostics
Imports System.Web.Services
Imports System.Web.Services.Protocols
Imports System.Xml.Serialization

Namespace MyMath
    
    <System.Web.Services.WebServiceBindingAttribute(Name:="MyMathSoap", [Namespace]:="http://www.contoso.com/")>  _
    Public Class MyMath
        Inherits System.Web.Services.Protocols.SoapHttpClientProtocol
        
        <System.Diagnostics.DebuggerStepThroughAttribute()>  _
        Public Sub New()
            MyBase.New
            Me.Url = "http://www.contoso.com/math.asmx"
        End Sub
        
        <System.Diagnostics.DebuggerStepThroughAttribute(),  _
         System.Web.Services.Protocols.SoapDocumentMethodAttribute("http://www.contoso.com/Add", RequestNamespace:="http://www.contoso.com/", ResponseNamespace:="http://www.contoso.com/", Use:=System.Web.Services.Description.SoapBindingUse.Literal, ParameterStyle:=System.Web.Services.Protocols.SoapParameterStyle.Wrapped)>  _
        Public Function Add(ByVal num1 As Integer, ByVal num2 As Integer) As Integer
            Dim results() As Object = Me.Invoke("Add", New Object() {num1, num2})
            Return CType(results(0),Integer)
        End Function
        
        <System.Diagnostics.DebuggerStepThroughAttribute()>  _
        Public Function BeginAdd(ByVal num1 As Integer, ByVal num2 As Integer, ByVal callback As System.AsyncCallback, ByVal asyncState As Object) As System.IAsyncResult
            Return Me.BeginInvoke("Add", New Object() {num1, num2}, callback, asyncState)
        End Function
        
        <System.Diagnostics.DebuggerStepThroughAttribute()>  _
        Public Function EndAdd(ByVal asyncResult As System.IAsyncResult) As Integer
            Dim results() As Object = Me.EndInvoke(asyncResult)
            Return CType(results(0),Integer)
        End Function
    End Class
End Namespace

下面的代码示例是 Math XML Web 服务，从中创建了前面的代理类。

<%@ WebService Language="C#" Class="MyMath"%>
 using System.Web.Services;
 using System;
 
 [WebService(Namespace="http://www.contoso.com/")] 
 public class MyMath {

    [ WebMethod ]
    public int Add(int num1, int num2) {
        return num1+num2;
    }
 }

<%@ WebService Language="VB" Class="MyMath"%>
Imports System.Web.Services
Imports System

<WebService(Namespace:="http://www.contoso.com/")> _
Public Class MyMath
    <WebMethod()> _
    Public Function Add(num1 As Integer, num2 As Integer) As Integer
        Return num1 + num2
    End Function 'Add
End Class 'Math

通常，除非要为 XML Web 服务生成自己的代理类，否则不会直接调用 BeginInvoke 方法。

由 Web 服务描述语言工具 (Wsdl.exe) 从服务说明生成的代理类将 XML Web 服务方法公开为派生自代理类的名称，以同步调用 XML Web 服务方法。 为了异步调用 XML Web 服务方法，将另外两个方法添加到每个 XML Web 服务方法的代理类中，一个方法将 Begin 前缀添加到 XML Web 服务方法的名称中，另一个方法 End 添加了 前缀。

代理类调用 BeginInvoke 方法以启动对 XML Web 服务方法的异步调用。 例如，如果 XML Web 服务公开名为 的 AddXML Web 服务方法，则代理类包含一个名为 BeginAdd的方法，用于启动对 XML Web service 方法的调用。 在 的代码 BeginAdd中，对 方法进行 BeginInvoke 调用，并将结果放入 的预期返回类型中 Add。

methodName用于查找可能已添加到 方法的自定义属性，例如 SoapDocumentMethodAttribute。 SoapDocumentMethodAttribute 提供有关 SOAP 协议所需的派生方法的其他信息。

asyncState 传入 callback ，并包含在 IAsyncResult 从 BeginInvoke 方法返回的 中。 参数 asyncState 可用于将有关异步调用上下文的信息（在 参数中指定的 callback ）传递给处理结果的委托。

• IAsyncResult
• AsyncCallback
• EndInvoke(IAsyncResult)
• SoapDocumentMethodAttribute
• WebClientProtocol