从javascript函数返回值到flex的问题答案

【问题标题】：Problem in returning values from javascript function to flex从javascript函数返回值到flex的问题
【发布时间】：2009-07-06 17:07:06
【问题描述】：

在附加的 flex 代码中，我试图在其 HTML 包装器中调用一个 javascript 函数。该示例也位于： http://www.cse.epicenterlabs.com/mbm/ajax_api.html 我面临的问题是，我必须单击两次按钮获得所需的输出。好像设置有延迟 “输出”变量。如何一键获取javascript函数的输出？

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
<mx:TextArea x="209" y="139" height="245" width="318"  id="text1" fontSize="28"/>
    <mx:Script>
        <![CDATA[
                import mx.rpc.events.ResultEvent;
    import flash.external.*;

     public function callWrapper():void {
        var s:String;
        if (ExternalInterface.available) {
           var wrapperFunction:String = "initialize";
           s = ExternalInterface.call(wrapperFunction,text1.text);
           text1.text = s;

        } else {
           s = "Wrapper not available";
        }
        trace(s); 
     }

                ]]>
    </mx:Script>
    <mx:Button x="92" y="118" label="Transliterate" click="callWrapper()"/>
</mx:Application>

HTML 包装器：

<!-- saved from url=(0014)about:internet -->
<html lang="en">

<!-- 
Smart developers always View Source. 

This application was built using Adobe Flex, an open source framework
for building rich Internet applications that get delivered via the
Flash Player or to desktops via Adobe AIR. 

Learn more about Flex at http://flex.org 
// -->

<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

<!--  BEGIN Browser History required section -->
<link rel="stylesheet" type="text/css" href="history/history.css" />
<!--  END Browser History required section -->

<title></title>
<script src="AC_OETags.js" language="javascript"></script>

<!--  BEGIN Browser History required section -->
<script src="history/history.js" language="javascript"></script>
<!--  END Browser History required section -->

<style>
body { margin: 0px; overflow:hidden }
</style>
<script language="JavaScript" type="text/javascript">
<!--
// -----------------------------------------------------------------------------
// Globals
// Major version of Flash required
var requiredMajorVersion = 9;
// Minor version of Flash required
var requiredMinorVersion = 0;
// Minor version of Flash required
var requiredRevision = 28;
// -----------------------------------------------------------------------------
// -->
</script>
</head>

<body scroll="no">
      <script type="text/javascript" src="http://www.google.com/jsapi"></script>
    <script type="text/javascript">

    google.load("language", "1");

        var output;
    function initialize(input) {
      google.language.transliterate([input], "en", "hi", function(result) {
        if (!result.error) {
          if (result.transliterations && result.transliterations.length > 0 &&
            result.transliterations[0].transliteratedWords.length > 0) {
            output = result.transliterations[0].transliteratedWords[0];
          }
        }
      });
    return output;
    }
    </script>
    <script language="JavaScript" type="text/javascript">
<!--
// Version check for the Flash Player that has the ability to start Player Product Install (6.0r65)
var hasProductInstall = DetectFlashVer(6, 0, 65);

// Version check based upon the values defined in globals
var hasRequestedVersion = DetectFlashVer(requiredMajorVersion, requiredMinorVersion, requiredRevision);

if ( hasProductInstall && !hasRequestedVersion ) {
    // DO NOT MODIFY THE FOLLOWING FOUR LINES
    // Location visited after installation is complete if installation is required
    var MMPlayerType = (isIE == true) ? "ActiveX" : "PlugIn";
    var MMredirectURL = window.location;
    document.title = document.title.slice(0, 47) + " - Flash Player Installation";
    var MMdoctitle = document.title;

    AC_FL_RunContent(
        "src", "playerProductInstall",
        "FlashVars", "MMredirectURL="+MMredirectURL+'&MMplayerType='+MMPlayerType+'&MMdoctitle='+MMdoctitle+"",
        "width", "100%",
        "height", "100%",
        "align", "middle",
        "id", "ajax_api",
        "quality", "high",
        "bgcolor", "#869ca7",
        "name", "ajax_api",
        "allowScriptAccess","sameDomain",
        "type", "application/x-shockwave-flash",
        "pluginspage", "http://www.adobe.com/go/getflashplayer"
    );
} else if (hasRequestedVersion) {
    // if we've detected an acceptable version
    // embed the Flash Content SWF when all tests are passed
    AC_FL_RunContent(
            "src", "ajax_api",
            "width", "100%",
            "height", "100%",
            "align", "middle",
            "id", "ajax_api",
            "quality", "high",
            "bgcolor", "#869ca7",
            "name", "ajax_api",
            "allowScriptAccess","sameDomain",
            "type", "application/x-shockwave-flash",
            "pluginspage", "http://www.adobe.com/go/getflashplayer"
    );
  } else {  // flash is too old or we can't detect the plugin
    var alternateContent = 'Alternate HTML content should be placed here. '
    + 'This content requires the Adobe Flash Player. '
    + '<a href=http://www.adobe.com/go/getflash/>Get Flash</a>';
    document.write(alternateContent);  // insert non-flash content
  }
// -->
</script>
<noscript>
    <object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
            id="ajax_api" width="100%" height="100%"
            codebase="http://fpdownload.macromedia.com/get/flashplayer/current/swflash.cab">
            <param name="movie" value="ajax_api.swf" />
            <param name="quality" value="high" />
            <param name="bgcolor" value="#869ca7" />
            <param name="allowScriptAccess" value="sameDomain" />
            <embed src="ajax_api.swf" quality="high" bgcolor="#869ca7"
                width="100%" height="100%" name="ajax_api" align="middle"
                play="true"
                loop="false"
                quality="high"
                allowScriptAccess="sameDomain"
                type="application/x-shockwave-flash"
                pluginspage="http://www.adobe.com/go/getflashplayer">
            </embed>
    </object>
</noscript>
</body>
</html>

【问题讨论】：

标签： javascript apache-flex transliteration

【解决方案1】：

那是因为google.language.transliterate 不是同步操作。您的 initialize 函数甚至在 google.language.transliterate 完成运行之前返回（这就是为什么您要附加一个回调函数以在它完成后运行）。

音译完成后需要回调一个actionscript函数。探索 ExternalInterface.addCallback() 以添加可从 javascript 调用的 actionscript 函数。

【讨论】：

【解决方案2】：

JavaScript 代码中对google.language.transliterate 的调用是异步的，这就是为什么您似乎必须按两次按钮的原因。在加载某些数据之前，作为第四个参数传递的匿名函数不会运行。

也许您应该在调用google.language.transliterate 之前显示某种加载指示器，然后将其隐藏在处理程序中？这样你就可以看到它何时加载数据。

【讨论】：

【解决方案3】：

您可以使用脚本创建一个 html 文件并在 Flex HTML 组件中使用它。

例子：

<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
    <mx:HTML id="html"
        width="100%"
        height="100%"
        location="{serverIp}/Translit.html"/>
</mx:WindowedApplication>

【讨论】：

【解决方案4】：

谢谢各位，成功了。我在这里附上工作代码：

弹性代码：(ajax_api.mxml)

<?xml version="1.0" encoding="utf-8"?>
    <mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
        <mx:TextArea x="209" y="139" height="245" width="318"  id="text1" fontSize="28"/>
        <mx:Script>
            <![CDATA[
                import mx.rpc.events.ResultEvent;
        import flash.external.*;

         public function callWrapper():void {
            var s:String;
            if (ExternalInterface.available) {
       ExternalInterface.addCallback("g", g);
               var wrapperFunction:String = "initialize";
               ExternalInterface.call(wrapperFunction,text1.text);

            } else {
               s = "Wrapper not available";
            }
            trace(s); 
         }
         public function g(str:String):void
         {
            text1.text = str;
         }

                ]]>
        </mx:Script>
        <mx:Button x="75" y="50" label="Enter some text and click this button to see the transliteration output" click="callWrapper()" height="37"/>
    </mx:Application>

HTML 包装器：

<!-- saved from url=(0014)about:internet -->
<html lang="en">

<!-- 
Smart developers always View Source. 

This application was built using Adobe Flex, an open source framework
for building rich Internet applications that get delivered via the
Flash Player or to desktops via Adobe AIR. 

Learn more about Flex at http://flex.org 
// -->

<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

<!--  BEGIN Browser History required section -->
<link rel="stylesheet" type="text/css" href="history/history.css" />
<!--  END Browser History required section -->

<title>ajax_api</title>
<script src="AC_OETags.js" language="javascript"></script>

<!--  BEGIN Browser History required section -->
<script src="history/history.js" language="javascript"></script>
<!--  END Browser History required section -->

<style>
body { margin: 0px; overflow:hidden }
</style>
<script language="JavaScript" type="text/javascript">
<!--
// -----------------------------------------------------------------------------
// Globals
// Major version of Flash required
var requiredMajorVersion = 9;
// Minor version of Flash required
var requiredMinorVersion = 0;
// Minor version of Flash required
var requiredRevision = 28;
// -----------------------------------------------------------------------------
// -->
</script>
</head>

<body scroll="no">
      <script type="text/javascript" src="http://www.google.com/jsapi"></script>
    <script type="text/javascript">

    google.load("language", "1");
function thisMovie(movieName)
{

    if(navigator.appName.indexOf("Microsoft")!=-1)
    {
        alert("microsoft");
        return window[movieName];
    }
    else
    {
        return document[movieName];
    }
}

function initialize(input) {
      google.language.transliterate([input], "en", "hi", function(result) {
        if (!result.error) {
          var container = document.getElementById("transliteration");
          if (result.transliterations && result.transliterations.length > 0 &&
            result.transliterations[0].transliteratedWords.length > 0) {
            output = result.transliterations[0].transliteratedWords[0];
        thisMovie("ajax_api").g(output);
          }
        }
      });
    }

    </script>
    <script language="JavaScript" type="text/javascript">
<!--
// Version check for the Flash Player that has the ability to start Player Product Install (6.0r65)
var hasProductInstall = DetectFlashVer(6, 0, 65);

// Version check based upon the values defined in globals
var hasRequestedVersion = DetectFlashVer(requiredMajorVersion, requiredMinorVersion, requiredRevision);

if ( hasProductInstall && !hasRequestedVersion ) {
    // DO NOT MODIFY THE FOLLOWING FOUR LINES
    // Location visited after installation is complete if installation is required
    var MMPlayerType = (isIE == true) ? "ActiveX" : "PlugIn";
    var MMredirectURL = window.location;
    document.title = document.title.slice(0, 47) + " - Flash Player Installation";
    var MMdoctitle = document.title;

    AC_FL_RunContent(
        "src", "playerProductInstall",
        "FlashVars", "MMredirectURL="+MMredirectURL+'&MMplayerType='+MMPlayerType+'&MMdoctitle='+MMdoctitle+"",
        "width", "100%",
        "height", "100%",
        "align", "middle",
        "id", "ajax_api",
        "quality", "high",
        "bgcolor", "#869ca7",
        "name", "ajax_api",
        "allowScriptAccess","sameDomain",
        "type", "application/x-shockwave-flash",
        "pluginspage", "http://www.adobe.com/go/getflashplayer"
    );
} else if (hasRequestedVersion) {
    // if we've detected an acceptable version
    // embed the Flash Content SWF when all tests are passed
    AC_FL_RunContent(
            "src", "ajax_api",
            "width", "100%",
            "height", "100%",
            "align", "middle",
            "id", "ajax_api",
            "quality", "high",
            "bgcolor", "#869ca7",
            "name", "ajax_api",
            "allowScriptAccess","sameDomain",
            "type", "application/x-shockwave-flash",
            "pluginspage", "http://www.adobe.com/go/getflashplayer"
    );
  } else {  // flash is too old or we can't detect the plugin
    var alternateContent = 'Alternate HTML content should be placed here. '
    + 'This content requires the Adobe Flash Player. '
    + '<a href=http://www.adobe.com/go/getflash/>Get Flash</a>';
    document.write(alternateContent);  // insert non-flash content
  }
// -->
</script>
<noscript>
    <object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
            id="ajax_api" width="100%" height="100%"
            codebase="http://fpdownload.macromedia.com/get/flashplayer/current/swflash.cab">
            <param name="movie" value="ajax_api.swf" />
            <param name="quality" value="high" />
            <param name="bgcolor" value="#869ca7" />
            <param name="allowScriptAccess" value="sameDomain" />
            <embed src="ajax_api.swf" quality="high" bgcolor="#869ca7"
                width="100%" height="100%" name="ajax_api" align="middle"
                play="true"
                loop="false"
                quality="high"
                allowScriptAccess="sameDomain"
                type="application/x-shockwave-flash"
                pluginspage="http://www.adobe.com/go/getflashplayer">
            </embed>
    </object>
</noscript>
</body>
</html>

【讨论】：