How Does Flex httpservice PASS Parameters (zt) to the backend)

ZT from: http://www.blogjava.net/yczz/articles/144363.html

 

I have read some documents recently and summarized some <mx: httpservice> methods for passing parameters to the background, as shown below:

Method 1: Use the urlvariables object

<? XML version = "1.0" encoding = "UTF-8"?> <Br/> <mx: Application xmlns: MX = "http://www.adobe.com/2006/mxml" <br/> layout = "absolute" fontsize = "12" <br/> <mx: SCRIPT> <br/> <! -- [CDATA [<br/> Import MX. controls. alert; <br/> Import MX. RPC. events. resultevent; <br/> // encode the parameters submitted to the backend. <br/> private function httpencoding (Param: string ): string {<br/> return encodeuricomponent (PARAM); <br/>}< br/> private function httpencoding0 (Param: string): String {<br/> return Param; // encodeuri (PARAM); <br/>}< br/> private function dorequest (): void {<br/> btn_do.enabled = false; <br/> va R URL: String = "http: // localhost: 8600/grid. JSP "; <br/> // The background will be garbled in the way below, no matter whether URI encoding is converted or not <br/> // URL + = "? User = "+ httpencoding0 (" username "); <br/> // URL + =" & psw = "+ httpencoding0 (" password "); <br/> // trace (URL); <br/> srv. url = URL; <br/> // srv. send (); <br/> // write normally as follows <br/> var Params: urlvariables = new urlvariables (); <br/> // the user, psw is the parameter user passed in to the background, and JSP uses request. getparameter ("user") to get <br/> Params. user = httpencoding ("username"); <br/> Params. psw = httpencoding ("password"); <br/> srv. send (Params); <br/>}< br/> private function resulthandler (Event: resultevent): void {<br/> alert. show ("the interaction with the background ends, and the foreground begins to obtain the data... "," prompt message "); <br/> btn_do.enabled = true; <br/>}< br/>] --> <br/> </MX: SCRIPT> <br/> <mx: httpservice id = "SRV" result = "resulthandler (event);"/> <br/> <mx: panel Title = "test and JSP background interaction" layout = "absolute" width = "100%" Height = "90%"> <br/> <mx: button id = "btn_do" label = "Get Data" Click = "dorequest ();"/> <br/> <mx: spacer Height = "1"/> <br/> <mx: DataGrid dataprovider = "{srv. lastresult. catalog. product} "width =" 100% "Height =" 100% "Y =" 28 "/> <br/> </MX: Panel> <br/> </MX: Application>Method 2: Use <mx: Request/> and demonstrate the usage of MX: State. [from the Internet]:

<? XML version = "1.0" encoding = "UTF-8"?> <Br/> <mx: Application xmlns: MX = "http://www.adobe.com/2006/mxml" layout = "absolute"> <br/> <mx: States> <br/> <mx: state name = "logged in"> <br/> <mx: setproperty target = "{Panel1}" name = "width" value = "95%"/> <br/> <mx: setproperty target = "{Panel1}" name = "height" value = "95%"/> <br/> <mx: removechild target = "{password}"/> <br/> <mx: removechild target = "{username}"/> <br/> <mx: removechild target = "{label1}"/> <B R/> <mx: removechild target = "{submit}"/> <br/> <mx: removechild target = "{label2}"/> <br/> <mx: setproperty target = "{Panel1}" name = "title" value = "members section"/> <br/> <mx: addchild relativeto = "{Panel1}" position = "lastchild"> <br/> <mx: label x = "10" Y = "10" text = "welcome to the members section! "/> <Br/> </MX: addchild> <br/> <mx: addchild relativeto = "{Panel1}" position = "lastchild"> <br/> <mx: label x = "10" Y = "36" text = "here you can do great things, like join the forums @ Viper creations! "/> <Br/> </MX: addchild> <br/> <mx: addchild relativeto = "{Panel1}" position = "lastchild"> <br/> <mx: label x = "10" Y = "62" text = "label"/> <br/> </MX: addchild> <br/> </MX: state> <br/> </MX: States> <br/> <mx: SCRIPT> <br/> <! -- [CDATA [<br/> Import MX. RPC. events. resultevent; </P> <p>]> <br/> </MX: SCRIPT> <br/> <mx: SCRIPT> </P> <p> <! [CDATA [<br/> private function checklogin (EVT: resultevent): void <br/>{< br/> If (EVT. result. loginsuccess = "yes") <br/>{< br/> currentstate = "logged in"; <br/>}< br/> If (EVT. result. loginsuccess = "no") <br/>{</P> <p> MX. controls. alert. show ('invalidusername/password'); <br/>}< br/>] --> <br/> </MX: SCRIPT> <br/> <mx: httpservice id = "login_user" result = "checklogin (Event) "showbusycursor =" true "method =" Post "url =" http://www.vipercreations.com/site_admin/login.php "useproxy =" false "> <br/> <mx: request xmlns = ""> <br/> <username> <br/> {username. text} <br/> </username> <br/> <password> <br/> {password. text} <br/> </password> <br/> </MX: Request> <br/> </MX: httpservice> </P> <p> <mx: panel resizeeffect = "resize" width = "250" Height = "200" layout = "absolute" Title = "Login System" horizontalcenter = "0" verticalcenter = "-2" id = ""Panel1"> <br/> <mx: label x = "10" Y = "10" text = "username:" id = "label1"/> <br/> <mx: textinput x = "10" Y = "36" id = "username"/> <br/> <mx: label x = "10" Y = "66" text = "Password:" id = "label2"/> <br/> <mx: textinput x = "10" Y = "92" id = "password" displayaspassword = "true"/> <br/> <mx: button x = "10" Y = "122" label = "Submit" id = "Submit" Click = "login_user.send ();"/> <br/> </MX: panel> </P> <p> </MX: Application>