ActionScript 3:错误#2025年

Question

我的代码很好用。当用户按1时，应该输入一个图像，当他/她按2时，将其替换为另一个图像。但是，当我在先前按相同的数字之后按1或2时，我会得到一个#2025错误。例:按1再按1。

ArgumentError:错误#2025年:提供的DisplayObject必须是调用方的子级。在flash.display::DisplayObjectContainer/removeChild() at warren_fla：：MainTimeline/reportKeyDown2 2()

代码

import flash.events.KeyboardEvent;

var bdata = new image1(stage.stageWidth, stage.stageHeight);
var bdata2 = new image2(stage.stageWidth, stage.stageHeight);
var bmp = new Bitmap(bdata);
var bmp2 = new Bitmap(bdata2);

function reportKeyDown(event:KeyboardEvent):void 
{ 
if (event.keyCode == 49) {
    //trace("1 is pressed");
    bmp.x = 230;
    bmp.y = 150;
    addChild(bmp);
}
if (contains(bmp2)) {
    removeChild(bmp2);
    }
}

function reportKeyDown2(event:KeyboardEvent):void 
{ 
if (event.keyCode == 50) {
    //trace("2 is pressed");
    bmp2.x = 230;
    bmp2.y = 150;
    addChild(bmp2);
    removeChild(bmp);
}

} 

stage.addEventListener(KeyboardEvent.KEY_DOWN, reportKeyDown);
stage.addEventListener(KeyboardEvent.KEY_DOWN, reportKeyDown2);

Answer 1

您正在删除bmp，而不检查它是否已经是子级。

function reportKeyDown2(event:KeyboardEvent):void 
{ 
    if (event.keyCode == 50) {
        //trace("2 is pressed");
        bmp2.x = 230;
        bmp2.y = 150;
        addChild(bmp2);
        if(contains(bmp)) 
            removeChild(bmp);
    }
} 

此外，您的代码可以重构到这个更简单的版本中：

import flash.events.KeyboardEvent;
import flash.ui.Keyboard;

var bdata = new image1(stage.stageWidth, stage.stageHeight);
var bdata2 = new image2(stage.stageWidth, stage.stageHeight);
var bmp = new Bitmap(bdata);
var bmp2 = new Bitmap(bdata2);

function reportKeyDown(event:KeyboardEvent):void 
{ 
    if (event.keyCode == Keyboard.NUMBER_1) {
        swapBitmaps(bmp, bmp2);            
    } else if (event.keyCode == Keyboard.NUMBER_2) {
        swapBitmaps(bmp2, bmp);            
    }
}

function swapBitmaps(first:Bitmap, second:Bitmap):void
{
      first.x = 230;
      first.y = 150;
      addChild(first);
      if(contains(second)) {        
           removeChild(second);
      }
}

stage.addEventListener(KeyboardEvent.KEY_DOWN, reportKeyDown);

Answer 2

在reportKeyDown()中，尝试移动：

if (contains(bmp2)) {
    removeChild(bmp2);
}

在检查密钥代码的if语句中：

function reportKeyDown(event:KeyboardEvent):void 
{ 
    if (event.keyCode == 49) {
        //trace("1 is pressed");
        bmp.x = 230;
        bmp.y = 150;
        addChild(bmp);

        if (contains(bmp2)) {
            removeChild(bmp2);
        }
    }
}

在reportKeyDown2中，在移除bmp之前，请检查是否是bmp：

function reportKeyDown2(event:KeyboardEvent):void 
{ 
    if (event.keyCode == 50) {
        //trace("2 is pressed");
        bmp2.x = 230;
        bmp2.y = 150;
        addChild(bmp2);

        if(contains(bmp))
        {
            removeChild(bmp);
        }
    }
}