在经过一段时间后从函数返回值?

让web服务在单独的线程中调用其长时间运行的部分。等一下,杀了它,如果时间太长就保释。请预先警告,这可能会使稀缺资源挂起(例如,数据库连接等),但您也可以修复此问题。

(抱歉,代码又快又脏,是演示版的,您应该详细说明并添加类型、webservice细节等。)

dim ResultFromWorker as String
dim DoneWorking as boolean

sub GetWebServiceMagicNumber
    DoneWorking = False
    dim t as new thread = addressof (GetWebServiceMagicNumber_Worker)
    t.start
    dim count as integer = 0
    while not DoneWorking and Count <100 
        count +=1
        System.Threading.Thread.Sleep(100) ' Important to not kill CPU time
    wend
    if DoneWorking then
        return ResultFromWorker
    else
        return "TimeOut"
    EndIf
end sub

sub GetWebServiceMagicNumber_Worker
    try
        ResultFromWorker = SearchTheWholeWorldForTheAnswer()
    catch ex1 as ThreadAbortException 
        ' ignore - My code caused this on purpose
        ' calling thread should clean up scarce resources, this is borrowed time
    catch ex2 as Exception
        ResultFromWorker = "Error - " & ex.tostring
    finally
        DoneWorking=True
    End Try
end sub

异步调用Web服务。

http://ondotnet.com/pub/a/dotnet/2005/08/01/async_webservices.html