一起谈.NET技术，Flex 数据访问 WebService （上） 狼人:

　　Flex 支持格式设置为 SOAP 消息且通过 HTTP 传输的 Web 服务请求和结果。SOAP 提供基于 XML 格式的定义，用于在 Web 服务客户端（如使用 Flex 构建的应用程序）和 Web 服务之间交换结构化和类型化信息。

　　在.NET和Flex的数据交互可以通过Web Services访问string，object，datatable，List<>,ArrayList等。

　　.NET和Flex的数据示例：

　　1、返回对象

　　定义返回对象的Web Method：

[WebMethod]
public Employee GetEmployee()
{
    return new Employee
    {
        id = 1,
        name = "Shawn",
        age = 25
    };
}

　　Flex前端代码：

  <?xml version="1.0" encoding="utf-8"?>
  <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
      <mx:Script>
          <![CDATA[
              import mx.rpc.events.FaultEvent;
              import mx.rpc.events.ResultEvent;
              import mx.controls.Alert;
              private function onResult(event:ResultEvent):void
              {
                  Alert.show(event.result.name);
              }
   
              private function onFault(event:FaultEvent):void
              {
                 Alert.show("调+event.message);
              }
   
              private function GetEmployee():void
              {
                  this.MyService.GetEmployee.send();
              }
          ]]>
      </mx:Script>
      <mx:Button label="Get Employee" click="GetEmployee()"/>
      
      <mx:WebService id="MyService" wsdl="http://localhost:4081Flex.asmx?WSDL" useProxy="false" result="onResult(event)" fault="onFault(event)">
          <mx:operation name="GetEmployee"/>
      </mx:WebService>
  </mx:Application>

　　运行结果：

　　2、返回DataTable

　　定义返回DataTable的Web Method：

[WebMethod]
public DataTable GetDataTable()
{
    DataTable dt = new DataTable("Employees");
    dt.Columns.Add("id", typeof(int));
    dt.Columns.Add("name", typeof(string));
    dt.Columns.Add("age", typeof(int));

    DataRow dr = dt.NewRow();
    dr["id"] = 1;
    dr["name"] = "Shawn";
    dr["age"] = 25;
    dt.Rows.Add(dr);

    dr = dt.NewRow();
    dr["id"] = 2;
    dr["name"] = "Jack";
    dr["age"] = 23;
    dt.Rows.Add(dr);

    return dt;
}

　　Flex前端代码：

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
    <mx:Script>
        <![CDATA[
            import mx.rpc.events.FaultEvent;
            import mx.rpc.events.ResultEvent;
            import mx.controls.Alert;
            private function onResult(event:ResultEvent):void
            {
            }
            private function onFault(event:FaultEvent):void
            {
               Alert.show("调+event.message);
            }
            private function GetDataTable():void
            {
                this.MyService.GetDataTable.send();
            }
        ]]>
    </mx:Script>
    <mx:Panel width="400">
        <mx:DataGrid id="gvEmployee" dataProvider="{this.MyService.GetDataTable.lastResult.Tables.Employees.Rows}" width="100%">
            <mx:columns>
                <mx:DataGridColumn headerText="ID" dataField="id"/>
                <mx:DataGridColumn headerText="Name" dataField="name"/>
                <mx:DataGridColumn headerText="Age" dataField="age"/>
            </mx:columns>
        </mx:DataGrid>
        <mx:ControlBar>
            <mx:Button label="Get DataTable" click="GetDataTable()"/>
        </mx:ControlBar>
    </mx:Panel>
    <mx:WebService id="MyService" wsdl="http://localhost:4081/Flex.asmx?WSDL" useProxy="false" result="onResult(event)" fault="onFault(event)">
        <mx:operation name="GetDataTable"/>
    </mx:WebService>
</mx:Application> 

　　运行结果：

　　3、返回List<>

[WebMethod]
public List<Employee> GetEmployeeList()
{
    return new List<Employee>
    {
        new Employee
        {
            id = 1,
            name = "Shawn",
            age = 25
        },
        new Employee
        {
            id = 2,
            name = "Jack",
            age = 23
        }
    };
}

　　Flex前端：

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
    <mx:Script>
        <![CDATA[
            import mx.collections.ArrayCollection;
            import mx.rpc.events.FaultEvent;
            import mx.rpc.events.ResultEvent;
            import mx.controls.Alert;
            private function onResult(event:ResultEvent):void
            {
                var arr:ArrayCollection = this.MyService.GetEmployeeList.lastResult as ArrayCollection;
                gvEmployee.dataProvider=arr;
            }

            private function onFault(event:FaultEvent):void
            {
               Alert.show("调+event.message);
            }
 
            private function GetEmployeeList():void
            {
                this.MyService.GetEmployeeList.send();
            }
        ]]>
    </mx:Script>

    <mx:Panel width="400">
        <mx:DataGrid id="gvEmployee" width="100%">
            <mx:columns>
                <mx:DataGridColumn headerText="ID" dataField="id"/>
                <mx:DataGridColumn headerText="Name" dataField="name"/>
                <mx:DataGridColumn headerText="Age" dataField="age"/>
            </mx:columns>
        </mx:DataGrid>
        <mx:ControlBar>
            <mx:Button label="Get List" click="GetEmployeeList()"/>
        </mx:ControlBar>
    </mx:Panel>
    <mx:WebService id="MyService" wsdl="http://localhost:4081/Flex.asmx?WSDL" useProxy="false" result="onResult(event)" fault="onFault(event)">
        <mx:operation name="GetEmployeeList"/>
    </mx:WebService>
</mx:Application>

　　运行结果：