关于webservice的异步调用简单实例
无论在任何情况下,被调用方的代码无论是被异步调用还是同步调用的情况下,被调用方的代码都是一样的,
下面,我们就以异步调用一个webservice 为例作说明。
这是一个webservice
???
_
??? Public Function delCurTable(ByVal tbName As String) As Boolean
??????? Try
??????????? Return True
??????? Catch ex As Exception
??????????? Return False
??????? End Try
??? End Function
(description:="试验")>
关于这个webservice的同步调用方法,我就不做说明了
异步调用:
?Private a As vbwebservice.DataManage'定义一个webservice变量
? Dim ar As IAsyncResult
public sub Callback1(byval ar as IAsyncResult)
''这里可以不写任何代码
'这里的代码在调用方运行结束后,开始运行
end sub
#region "异步调用"
private sub btnStart_Click()
dim cb as asyncallback=new asyncallback(address(me.callback1))
ar=a.begindelcurtable("zdf",cb,a)
end sub
private sub btnEnd_Click()
if ar is nothing then
exit sub
end if
if? ar.IsCompleted Then
dim m as boolean=a.enddelcurtable(ar)
messagebox.show(m.tostring)
end if
end sub
#end region
注意:“返回异步调用的结果一次只能调用一次,如果想再执行一遍,就必须重新执行一遍begin的方法”
以上是vb.net的用法,下面是c#的用法
CWebService.DataManage? a;
??System.IAsyncResult ar;
??private void Form1_Load(object sender,System.EventArgs e)
??{
???a=new CWebService.DataManage();
??}
??public void CallBack1(System.IAsyncResult ar)
??{
???string a;
???a=ar.AsyncState.ToString();
???switch (a)
???{
????case "zhang":
?????MessageBox.Show("zhang");
?????break;
????case "wang":
?????MessageBox.Show("wang");
?????break;
????default:
?????MessageBox.Show("default");
?????break;
???}
??}
??private void btnStart_Click(object sender,System.EventArgs e)
??{
???System.AsyncCallback cb=new AsyncCallback(this.CallBack1);
ar=a.BegindelCurTable("zhang","zhang");
??}
??private void btnEnd_Click(object sender,System.EventArgs e)??{???if(ar==null)???{????MessageBox.Show("null");????return ;???}???if(ar.IsCompleted )???{????bool m=a.EnddelCurTable(ar);????MessageBox.Show(m.ToString());???}???else???{????MessageBox.Show("为完成");???}??}