需要帮助在c# 4.0 Web服务客户端中实现异步调用

所以我正在开发一个使用web服务的客户端。我使用来自服务的WSDL和XSD文件来生成代理类，所有同步函数都运行良好。然而，考虑到它们的同步特性，进行任何调用都会导致UI停止响应，直到调用完成。使用异步方法的经典原因，对吧?

问题是，我还在学校攻读学位，对异步编程知之甚少。我试着在网上查阅相关资料(我的雇主甚至有一个Books全天候订阅服务)，但我很难掌握应该如何打电话以及如何处理回应。我有:

    /// <remarks/>
    [System.Web.Services.Protocols.SoapDocumentMethodAttribute("http://localhost:8080/getRecords", RequestNamespace="http://www.<redacted>.com/ws/schemas", ResponseNamespace="http://www.<redacted>.com/ws/schemas", Use=System.Web.Services.Description.SoapBindingUse.Literal, ParameterStyle=System.Web.Services.Protocols.SoapParameterStyle.Wrapped)]
    [return: System.Xml.Serialization.XmlArrayAttribute("records", Form=System.Xml.Schema.XmlSchemaForm.Unqualified, IsNullable=true)]
    [return: System.Xml.Serialization.XmlArrayItemAttribute("list", Form=System.Xml.Schema.XmlSchemaForm.Unqualified, IsNullable=false)]
    public record[] getRecords([System.Xml.Serialization.XmlElementAttribute(Form=System.Xml.Schema.XmlSchemaForm.Unqualified, IsNullable=true)] string username, [System.Xml.Serialization.XmlArrayAttribute(Form=System.Xml.Schema.XmlSchemaForm.Unqualified, IsNullable=true)] [System.Xml.Serialization.XmlArrayItemAttribute("list", Form=System.Xml.Schema.XmlSchemaForm.Unqualified, DataType="integer", IsNullable=false)] string[] ids) {
        object[] results = this.Invoke("getRecords", new object[] {
                    username,
                    ids});
        return ((record[])(results[0]));
    }
    /// <remarks/>
    public void getRecordsAsync(string username, string[] ids) {
        this.getRecordsAsync(username, ids, null);
    }
    /// <remarks/>
    public void getRecordsAsync(string username, string[] ids, object userState) {
        if ((this.getRecordsOperationCompleted == null)) {
            this.getRecordsOperationCompleted = new System.Threading.SendOrPostCallback(this.OngetRecordsOperationCompleted);
        }
        this.InvokeAsync("getRecords", new object[] {
                    username,
                    ids}, this.getRecordsOperationCompleted, userState);
    }
    private void OngetRecordsOperationCompleted(object arg) {
        if ((this.getRecordsCompleted != null)) {
            System.Web.Services.Protocols.InvokeCompletedEventArgs invokeArgs = ((System.Web.Services.Protocols.InvokeCompletedEventArgs)(arg));
            this.getRecordsCompleted(this, new getRecordsCompletedEventArgs(invokeArgs.Results, invokeArgs.Error, invokeArgs.Cancelled, invokeArgs.UserState));
        }
    }

还有这个:

/// <remarks/>
[System.CodeDom.Compiler.GeneratedCodeAttribute("System.Web.Services", "4.0.30319.1")]
[System.Diagnostics.DebuggerStepThroughAttribute()]
[System.ComponentModel.DesignerCategoryAttribute("code")]
public partial class getRecordsCompletedEventArgs : System.ComponentModel.AsyncCompletedEventArgs {
    private object[] results;
    internal getRecordsCompletedEventArgs(object[] results, System.Exception exception, bool cancelled, object userState) : 
            base(exception, cancelled, userState) {
        this.results = results;
    }
    /// <remarks/>
    public record[] Result {
        get {
            this.RaiseExceptionIfNecessary();
            return ((record[])(this.results[0]));
        }
    }
}

:

/// <remarks/>
[System.CodeDom.Compiler.GeneratedCodeAttribute("System.Web.Services", "4.0.30319.1")]
public delegate void getRecordsCompletedEventHandler(object sender, getRecordsCompletedEventArgs e);

我之所以选择这个例子，是因为同步调用有返回类型，而异步调用没有——至少在函数调用本身中没有。我知道getRecordsCompletedEventArgs类具有正确的返回类型，这就是我将如何从调用中获取数据。我不明白的是怎么做。

假设我用getRecordsAsync:

替换当前对getRecords的调用

1. 我如何设置客户端响应时，异步调用完成?我需要使用我已经编写的LINQ过程将XML放入一个文件中，我需要记录操作的成功或失败，并且我需要通知用户操作完成。

2. 我如何确保使呼叫实际上异步发生?我记得有一次读到，简单地调用异步SOAP方法实际上不会对当前线程异步发生，除非您先做其他事情。任何建议吗?

3. 还有其他重要的考虑因素吗?(例如:"如果你忘记做这个，它会炸毁你的程序!")

这些都是到目前为止我还没能找到令人信服的确切答案的问题。

RecordClient client = new RecordClient();
//attaching an event handler
client.getRecordsCompleted += onGetRecordsCompleted;
//calling the web service asynchronously
client.getRecordsAsync("username", [ids]);

//definition of onGetRecordsCompleted of type getRecordsCompletedEventHandler
private void onGetRecordsCompleted(object sender, getRecordsCompletedEventArgs e)
{
  if(e.Error != null)
  {
    record[] data = e.Result;
    //do something with your data
  }
  else
  {
    //handle error
  }
}