Question

由于某种原因，我的值没有在函数之外更新。我正在尝试制作一个按钮，例如“加”，不断向上移动电影剪辑“topArrow”。我认为布尔值是一种简单的触发方式，但它不会在函数之外更新。这是为什么？

import flash.events.Event;
import flash.events.MouseEvent;

var speed:Number = 1;

plus.addEventListener(MouseEvent.MOUSE_DOWN, arrow_up);
plus.addEventListener(MouseEvent.MOUSE_UP, arrow_stop);
minus.addEventListener(MouseEvent.MOUSE_DOWN, arrow_down);
minus.addEventListener(MouseEvent.MOUSE_UP, arrow_stop);

var move_up:Boolean = false;
var move_down:Boolean = false;



function arrow_up(event:MouseEvent):void
{
    trace("button pressed");
    move_up = true;
}


function arrow_stop(event:MouseEvent):void
{

    move_up = false;
    move_down = false;
}

function arrow_down(event:MouseEvent):void
{

    move_down = true;
}

while (move_up==true)
{
    topArrow.y +=  speed;
}

while (move_down==true)
{
    topArrow.y -=  speed;
}

if(move_up)
{
    trace("true");
}

Answer 1

那些while循环是可怕的，一旦move_up为true，它将进入该循环并永不退出？

我会做类似下面的事情而不是动画影片剪辑：

var speed:Number = 1;

plus.addEventListener(MouseEvent.MOUSE_DOWN, arrow_up);
plus.addEventListener(MouseEvent.MOUSE_UP, arrow_stop);
minus.addEventListener(MouseEvent.MOUSE_DOWN, arrow_down);
minus.addEventListener(MouseEvent.MOUSE_UP, arrow_stop);

stage.addEventListener(Event.ENTER_FRAME, onEnterFrame);

var move_up:Boolean = false;
var move_down:Boolean = false;

function arrow_up(event:MouseEvent):void
{
    trace("button pressed");
    move_up = true;
}

function arrow_stop(event:MouseEvent):void
{
    move_up = false;
    move_down = false;
}

function arrow_down(event:MouseEvent):void
{
    move_down = true;
}

function onEnterFrame(event:Event):void
{
   if(move_up)
       topArrow.y += speed;
   else if(move_down)
       topArrow.y -=speed;

   if(move_up)
   {
      trace("true");
   }
}

Answer 2

反编译二进制文件并查看move_up setter函数。

as3布尔变量不会传递出函数

2 个答案: