Adobe动画CC动态文本无效错误

Question

我有这个错误

" typeError：错误＃1009：无法访问null对象引用的属性或方法。 在sole_fla :: navenimeline/game（）"

我似乎无法在我创建的动态文本框上显示我的分数

这是我的代码

import flash.events.Event;
import flash.events.KeyboardEvent;
import flash.ui.Keyboard;
import flash.display.MovieClip;

addEventListener(Event.ENTER_FRAME, game);
addEventListener(MouseEvent.CLICK, onClick);
var score:int = 0;
var high:int = 0;
const gravity:Number = 2;
const force: Number = 30;
const lyfe: Number = 100;
var yspeed: Number = 249;
var life: Number = 0;
function onClick(event:MouseEvent):void
{
     //just testing if mouse input is detected
     trace("The event handler works!");
}


//game main loop
function game(event: Event) {

    score = 0;
    life = lyfe;
    yspeed = yspeed + gravity;
    player.y = yspeed;
    if(player.y - player.height/2 < 0)
            player.y = player.height/2;
    for (var i = 0; i < numChildren; i++) {

    //test if mons hit player
    if (mons.hitTestObject(player)){
        life = life - 10;
        trace("hit");
    }
    //test if starz hit player
    if (starz.hitTestObject(player)){
       //I believe this is the part where it gets the error
       //this is my scoretext dynamic text box to display the score
        scoretext.text = score.toString();
        ++score;
    }

}
}
stage.addEventListener(KeyboardEvent.KEY_DOWN, fl_KeyboardDownHandler_2);
function fl_KeyboardDownHandler_2(event:KeyboardEvent):void
{
if(event.keyCode == 32){
    yspeed = yspeed - force;
    trace("Key Code Pressed: " + event.keyCode);
    player.gotoAndPlay(41);
}
}

Answer 1

更改帧与持久的事件侦听器相处得很好。执行侦听器，但是如果对象在当前帧上不存在，则对对象的引用为null。

当您的应用程序中切换状态时，通过删除事件听众正确终止先前状态。