在加载函数外丢失数组数据

Question

尝试制作基于网格的问题答案游戏，并使用for循环将文本文件加载到数组中。我想减少冗余代码并使用循环来填充我的数组。我遇到的问题是我的数组在加载函数外丢失/销毁。

我明白，如果一个数组是在函数内声明的，那么数组自然会在函数退出时被销毁。不过，我在函数之外声明数组，以便在退出函数后数组应保持完整。

我在这里错过了什么？

顺便说一句 - 我没有加载数据的问题。数据加载正确。数据加载完成后，阵列就会被销毁。

//Create the arrays to hold the 
//categories, questions, and answers 
var categoryArray:Array = new Array();  
var quesAnswArray:Array = new Array(); 

//create the loader 
var loader:URLLoader = new URLLoader(); 

//telling the loader that we are dealing with variables here. 
loader.dataFormat = URLLoaderDataFormat.VARIABLES; 

//This is an eventlistener, these are used all the time in AS3 
//learn to use them, this basically tells flash to listen to a specific event 
//and then call a specific function. 
//in Our case we listen for the event called COMPLETE which means it will active 
//a function called "loading" when our flash movie has completed loading 
loader.addEventListener(Event.COMPLETE, loading); 

//Here we tell our loading which file to read our categories and questions from. 
loader.load(new URLRequest("questions.txt")); 

//This is the function that will happen when the eventlistener activates. 
//basically it says that our text fields called content_1 and _2's text property 
//should be equal to loader.data.var_1 and var_2 (as you might remember from the  explanation above). 
function loading (event:Event):void{ 

    //loading bar 
    var total:Number = this.stage.loaderInfo.bytesTotal; 
    var loaded:Number = this.stage.loaderInfo.bytesLoaded; 

    bar_mc.scaleX = loaded/total; 
    loader_txt.text = Math.floor((loaded/total)*100)+ "%"; 

    var varText:URLVariables = new URLVariables(event.target.data); 
    //populate the category array with the value from the file. 
    for (var category:int=0; category<13; category++) 
     { 
      this["cat"+category] = varText["var_" + [category+1]]; 
      categoryArray.push(this["cat"+category]); 
     } 
    //populate the two demensional array of questions and answers. 
     //columns 
    for (var cols:int=0; cols<12; cols++){ 
      //rows 
      for (var rows:int=0; rows<5; rows++){ 
       this["q"+rows] = varText["var_c"+[cols+1]+"q"+[rows+1]]; 
       this["a"+rows] = varText["var_c"+[cols+1]+"a"+[rows+1]]; 
       quesAnswArray.push(new Array()); 
       quesAnswArray[cols].push(this["q"+rows]); 
       quesAnswArray[cols].push(this["a"+rows]); 
      } 
     } 
    //bonus round q&a 
    this["finalQ"] = varText["var_c13q1"]; 
    this["finalA"] = varText["var_c13a1"]; 
    quesAnswArray.push(this["finalQ"]); 
    quesAnswArray.push(this["finalA"]); 

    if (total == loaded){ 
    play(); 
    this.removeEventListener(Event.ENTER_FRAME, loading); 
    } 

    trace(categoryArray); // this traces the array values perfectly 
    trace(categoryArray.length); // this returns 13 which is correct 
} 

trace(categoryArray); //this gives me nothing. 
trace(categoryArray.length) //gives me 0 

Answer 1

你的代码做它应该做的事情。发生什么事是你的loading()函数被异步调用，一旦数据已被Flash接收。所以基本上你的最后一个跟踪语句在loading()之前，以及数组初始化之前执行。

所以只要确保在调用loading()之后访问数组。也许创建一个函数，如initialize()，它将包含您的初始化代码。并在loading()的末尾调用该函数。