Flash AS3，从输入字段获取文本

Question

回到AS3并使用textinput卡住了，当我跟踪文本变量时，输出窗口显示为null？

该变量名为stext：String，捕获文本函数返回null？

package  {
//Import Statements
import flash.display.MovieClip;
import flash.events.*;
import flash.text.TextField;

public class MyAppMain extends MovieClip {

    /* --------------
    DECLARE VARIABLES
    ---------------*/
    var search:MovieClip;
    var searchText:MovieClip;
    var stext:String;



    public function MyAppMain() {
        // constructor code

        loadSearch();               //CALL LOADSEARCH FUNCTION
    }

    function loadSearch(){
        //LOAD SEARCH BUTTON
        search = new Search_btn;
        search.x = 10;
        search.y = 10;
        search.buttonMode = true;
        addChild(search);
        search.addEventListener(MouseEvent.CLICK, test);

        //LOAD TEXT AREA
        searchText = new SearchText_txt;
        searchText.x = 10;
        searchText.y = 50;
        addChild(searchText);

    }

    function test(e:MouseEvent):void{
        captureText();
        trace ("I have arrived at test")

    }
    function captureText():void{
        stext = searchText.text;
        trace ("Answer" +stext);
    }




}

}