Flash AS3:提供的DisplayObject必须是调用者错误的子对象

我正在创建一些动作脚本来模拟3个按钮状态，并相应地加载到电影剪辑中

我犯了这个错误

ArgumentError: Error #2025: The supplied DisplayObject must be a child of the caller.
    at flash.display::DisplayObjectContainer/removeChild()
    at Untitled_fla::MainTimeline/sack_btnMouseOut()

当你试图这么做的时候

//get the objects
var addSackStill:sack_still = new sack_still();
var addSackHover:sack_hover = new sack_hover();
var addSackClick:sack_click = new sack_click();

//add the still object to the stage
addChild(addSackStill);
var SACK_X = 570.55;
var SACK_Y = 603.95;
addSackStill.x = SACK_X;
addSackStill.y = SACK_Y;
addSackHover.x = SACK_X;
addSackHover.y = SACK_Y;
addSackClick.x = SACK_X;
addSackClick.y = SACK_Y;

//create the event listeners
addSackStill.addEventListener(MouseEvent.MOUSE_OVER, sack_btnMouseOver);
addSackHover.addEventListener(MouseEvent.MOUSE_OUT, sack_btnMouseOut);
addSackHover.addEventListener(MouseEvent.CLICK, sack_btnClick);


//here are the functions for mouse over, mouse off, and click
function sack_btnMouseOver(event:MouseEvent):void {
    trace("mouse over");
    removeChild(addSackStill); //remove the movie clip
    addChild(addSackHover); //add sackclick to the stage
}

function sack_btnMouseOut(event:MouseEvent):void {
    trace("mouse out");
    removeChild(addSackHover); //remove the movie clip
    addChild(addSackStill); //add sackclick to the stage
}

function sack_btnClick(event:MouseEvent):void {
    trace("Click");
    removeChild(addSackHover); //remove the movie clip
    addChild(addSackStill); //add sackclick to the stage
}

---

我做错什么了吗？

我假设在您试图删除它们时它们没有被添加。在删除父对象之前，请确保父对象存在。此外，您可以尝试parent.removeChild，而不是该对象的remove：

//here are the functions for mouse over, mouse off, and click
function sack_btnMouseOver(event:MouseEvent):void {
    trace("mouse over");
    if (addSackStill.parent) { addSackStill.parent.removeChild(addSackStill); } //remove the movie clip
    addChild(addSackHover); //add sackclick to the stage
}

function sack_btnMouseOut(event:MouseEvent):void {
    trace("mouse out");
    if (addSackHover.parent) { addSackHover.parent.removeChild(addSackHover); } //remove the movie clip
    addChild(addSackStill); //add sackclick to the stage
}

function sack_btnClick(event:MouseEvent):void {
    trace("Click");
    if (addSackHover.parent) { addSackHover.parent.removeChild(addSackHover); } //remove the movie clip
    addChild(addSackStill); //add sackclick to the stage
}

---

我在想，如果是这种情况，会抛出一个空对象引用错误吗？这是两种可能的情况——空父对象和非已删除子对象的父对象……如果我从试图删除的对象调用removeChild，通常会出现此错误。。尝试将removeChild包装在if（thing.parent）thing.parent.removeChild（thing）中；