Actionscript 3 AS3:无法访问空对象引用的属性或方法(尽管删除了事件侦听器)
我正在AS3中编程一个2D侧面滚动平台。我有一个可以随播放器滚动的相机,虽然它保持在固定的高度Actionscript 3 AS3:无法访问空对象引用的属性或方法(尽管删除了事件侦听器),actionscript-3,flash,Actionscript 3,Flash,我正在AS3中编程一个2D侧面滚动平台。我有一个可以随播放器滚动的相机,虽然它保持在固定的高度 import flash.events.Event; import flash.geom.Rectangle; stage.addEventListener(Event.ENTER_FRAME, camera); function camera(evt:Event){ root.scrollRect = new Rectangle(player.x - stage.stageWidth/2, cam
import flash.events.Event;
import flash.geom.Rectangle;
stage.addEventListener(Event.ENTER_FRAME, camera);
function camera(evt:Event){
root.scrollRect = new Rectangle(player.x - stage.stageWidth/2, camera1.y - stage.stageHeight/2, stage.stageWidth, stage.stageHeight);}
我已经编程了一个坑,如果玩家掉入坑中,它将在一个单独的画面上带玩家在屏幕上观看游戏。此函数用于从帧中删除所有事件侦听器
stage.addEventListener(Event.ENTER_FRAME, walls);
function walls(e:Event){
if (player.hitTestObject(Pit1)){
stage.removeEventListener(KeyboardEvent.KEY_DOWN, keydown);
stage.removeEventListener(KeyboardEvent.KEY_UP, keyup);
stage.removeEventListener(Event.ENTER_FRAME, movement);
stage.removeEventListener(Event.ENTER_FRAME, walls);
stage.removeEventListener(Event.ENTER_FRAME, camera);
gotoAndPlay("GameOver");
}
}
但是,当我在屏幕上观看游戏时,我仍然收到相机的TypeError#1009。您应该创建一个独特的函数来处理enterframe事件。刷新视图并在该唯一函数中测试碰撞:
/**
* Init function, called at the end.
*/
function init()
{
stage.addEventListener(Event.ENTER_FRAME, enterFrameEventHandler);
}
/**
* Function that updates your camera
*/
function updateCamera()
{
root.scrollRect = new Rectangle(player.x - stage.stageWidth/2, camera1.y - stage.stageHeight/2, stage.stageWidth, stage.stageHeight);
}
/**
* Function that test your collisions.
*/
function testCollision()
{
if (player.hitTestObject(Pit1))
{
stage.removeEventListener(KeyboardEvent.KEY_DOWN, keydown);
stage.removeEventListener(KeyboardEvent.KEY_UP, keyup);
stage.removeEventListener(Event.ENTER_FRAME, enterFrameEventHandler);
gotoAndPlay("GameOver");
}
}
/**
* Unique function that manages enterframe events
*/
function enterFrameEventHandler(e:Event)
{
// update camera position
updateCamera();
// test collision
testCollision();
// etc.
}
init();
确保在第一帧(或初始屏幕帧)之外实例化相机