c# - 如何使用 AsyncCallback 获取方法结果？

Question

我希望你能帮助我解决以下问题：

我有一个 WebService 方法，它应该返回一个 CompensationPlanReturnReturn 对象数组。该方法是这样调用的：

//This is the object I need to instanciate  because it contains the method I wanna call
CompensationPlan_Out_SyncService test = new CompensationPlan_Out_SyncService();
//This is the method that is supposed to return me an array of CompensationPlanReturnReturn objects
//The data.ToArray() is the parameter the method need, then I pass the method that I wanna run when the method finishes and I dont know what to pass as the final parameter
test.BeginCompensationPlan_Out_Sync(data.ToArray(), new AsyncCallback(complete), null)

//The method description is:
public System.IAsyncResult BeginCompensationPlan_Out_Sync(CompensationPlanDataCompensationPlan[] CompensationPlanRequest, System.AsyncCallback callback, object asyncState)

//On this method I'd like to access to the resuls (the array of CompensationPlanReturnReturn) but I dont know how
private void complete(IAsyncResult result)
    {            
        lblStatus.Text = "Complete";
    }

Answer 1

您需要调用test.EndCompensationPlan_Out_Sync(result)，它将返回异步操作的结果，或者如果发生错误则抛出异常。

Answer 2

异步方法分为两个子方法 -Begin和End.

您需要调用EndCompensationPlan_Out_Sync以获取方法返回的实际结果 -

private void complete(IAsyncResult result)
{            
    var actualResult = test.EndCompensationPlan_Out_Sync(result);
    lblStatus.Text = "Complete";
}

Answer 3

尝试使用 AsyncState-Property 并将其转换为给定的类型。

像这样：

cSACommand = (SACommand)Result.AsyncState;