在上一節(jié)，我們利用FrontController 去映射 Event與Command

在這一節(jié)我們主要針對Command這部分動作做介紹。在RIA應(yīng)用程序中，不可或缺的部份就是跟后臺服務(wù)器連接進行數(shù)據(jù)傳遞。Command通過Delegate去做Services的部份(包含Remoting,WebServices,…等)

Command: 操作Cairngorm Business以及呼叫Cairngorm Delegates，這些回傳所取得的資料Command會再將它更新到Model Locator Delegate: 由Command所產(chǎn)生，將遠程呼叫(RPC:remote procedure calls[HTTP, Web Services, etc])實例化，并將結(jié)果傳回給Command。 Service:用來定義連接Server端的呼叫(RPC:remote procedure calls[HTTP, Web Services, etc])，來獲取遠程數(shù)據(jù)。?
在Delegate中我們會作一個call service的部份，而Services相關(guān)的定義與設(shè)定，就紀(jì)錄在Service Locator。

延續(xù)上一個項目，我們修改LoginCommand的部份要通過Delegate去做Remoting，呼叫Server端 login function，去數(shù)據(jù)庫查看判斷賬號密碼是否正確。

所以我們先在項目中新增business文件夾。

新增兩個文件，一個是Service.mxml組件。用來定義紀(jì)錄可以使用的Services。

因為組件的類型不是內(nèi)建，所以先隨便選一個再改mxml的內(nèi)容
這里示范的是使用搭配.NET Remoting的Freeware ” FluorineFx “，可以參考這裡。

代碼如下：

<?xml version="1.0" encoding="utf-8"?>
<cairngorm:ServiceLocator
xmlns:mx="http://www.adobe.com/2006/mxml"
xmlns:cairngorm="com.adobe.cairngorm.business.*">

<!-- Login Service -->
<mx:RemoteObject
id="Remoting_Services"
source="Remoting.Services"
destination="fluorine"
showBusyCursor="true">
<mx:method name="login" />
</mx:RemoteObject>

</cairngorm:ServiceLocator>

?

另一個是LoginDelegate.as類，用來連接Service，并將取得的資料回傳給Command。

代碼如下：

package org.rianotes.CairngormSample.business { import com.adobe.cairngorm.business.ServiceLocator;import mx.rpc.IResponder;import org.rianotes.CairngormSample.vo.User;public class LoginDelegate {private var responder:IResponder;private var service:Object;public function LoginDelegate(responder:IResponder) {this.responder = responder;//透過ServiceLocator取得連接Service的方式this.service = ServiceLocator.getInstance().getRemoteObject("Remoting_Services");}public function login(loginAttempt:User):void{//這部份要跟Server端Remoting Service 的名字相同傳入值型態(tài)也要相同var call:Object = service.login(loginAttempt);//處理伺服器的傳回值call.addResponder( responder );}} } 為了傳送賬號和密碼，所以也要針對Value object作修改 User - Value objectpackage org.rianotes.CairngormSample.vo {//.NET 那邊User.cs的 namespace[RemoteClass(alias="Remoting.Objects.User")]public class User{public var UserID:String;public var Password:String;public var Email:String;public function User(){}} }

然后在LoginCommand中加入Responder要用到的result,fault function
代碼如下：

package org.rianotes.CairngormSample.commands {import com.adobe.cairngorm.commands.ICommand;import com.adobe.cairngorm.control.CairngormEvent;import mx.controls.Alert;import mx.rpc.IResponder;import org.rianotes.CairngormSample.business.LoginDelegate;import org.rianotes.CairngormSample.events.LoginEvent;import org.rianotes.CairngormSample.model.ViewModelLocator;//加入IResponder 的Interfac才會呼叫result,falut ↓↓↓ public class LoginCommand implements ICommand , IResponder{public var model:ViewModelLocator = ViewModelLocator.getInstance();public function LoginCommand(){}//ICommand Interface functionpublic function execute(event:CairngormEvent):void{var loginEvent:LoginEvent = event as LoginEvent;var delegate:LoginDelegate = new LoginDelegate(this);delegate.login(loginEvent.loginAttempt);}//delegate.login 成功取得回傳時做的functionpublic function result( event :Object):void{if(event.result == true){model.workflowState = ViewModelLocator.MAIN_SCREEN;}else{mx.controls.Alert.show("請確認帳號密碼是否正確！？");}}//delegate.login 失敗時做的functionpublic function fault( event :Object):void{trace("連線錯誤")}} }

?

LoginView.mxml也要做部分修改，代碼如下：

<?xml version="1.0" encoding="utf-8"?>
<mx:VBox xmlns:mx="http://www.adobe.com/2006/mxml"
horizontalAlign="right" xmlns:components="org.rianotes.CairngormSample.view.components.*">
<mx:Script>
<![CDATA[
import org.rianotes.CairngormSample.vo.User;
import org.rianotes.CairngormSample.events.LoginEvent;
import org.rianotes.CairngormSample.model.ViewModelLocator;
[Bindable]
private var model:ViewModelLocator = ViewModelLocator.getInstance();

private function login(e:MouseEvent):void{
var user:User = new User();
user.UserID = ti_UserID.text;
user.Password = ti_Password.text;

var loginEvent:LoginEvent = new LoginEvent(user);

//發(fā)送Login Event
loginEvent.dispatch();
}

]]>
</mx:Script>
<mx:Form borderStyle="solid" width="100%">
<mx:FormItem label="UserID :" width="100%">
<mx:TextInput id="ti_UserID" width="100%"/>
</mx:FormItem>

<mx:FormItem label="Password: " width="100%">
<mx:TextInput id="ti_Password" width="100%"/>
</mx:FormItem>
</mx:Form>

<mx:Button label="Login" click="login(event)" />
</mx:VBox>

?

?

最后我們在Main.mxml中加入Service
代碼如下：

<?xml version="1.0" encoding="utf-8"?>
<mx:Application
xmlns:mx="http://www.adobe.com/2006/mxml"
xmlns:view="org.rianotes.CairngormSample.view.*"
layout="absolute" xmlns:control="org.rianotes.CairngormSample.control.*" xmlns:business="org.rianotes.CairngormSample.business.*">

<mx:Script>
<![CDATA[
import org.rianotes.CairngormSample.model.ViewModelLocator;
[Bindable]
private var model:ViewModelLocator = ViewModelLocator.getInstance();
]]>
</mx:Script>

<!--Cairngorm FrontController :讓app中擁有SampleController-->
<control:SampleController id="controller" />

<!--Cairngorm Services-->
<business:Services id="services" />

<mx:ViewStack id="vsMain" width="100%" height="100%"
selectedIndex="{model.workflowState}">

<!--第0個View-->
<view:LoginView />

<!--第1個View-->
<view:MainView />
</mx:ViewStack>
</mx:Application>

?

轉(zhuǎn)載于:https://www.cnblogs.com/GFantasy/archive/2010/02/24/1672300.html

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