actionscript 3 添加和刪除影片剪輯按鈕

Question

試圖在 actionscript 上制作按鈕：創建和刪除影片剪輯對象，但總是出現一些錯誤...我需要一個按鈕創建影片剪輯，另一個必須通過鼠標單擊將其刪除。 這是代碼：

import flash.events.MouseEvent;
import flash.display.MovieClip;
import flash.text.TextField;

main.addEventListener(MouseEvent.CLICK, addMain);
function addMain(e: MouseEvent) {
    var movieClip: bm = new bm();
    movieClip.x = 640;
    movieClip.y = 570;
    this.addChild(movieClip);
    main.removeEventListener(MouseEvent.CLICK, addMain);
    deletemain.removeEventListener(MouseEvent.CLICK, addMain);
}

deletemain.addEventListener(MouseEvent.CLICK, deleteMain);
function deleteMain(e: MouseEvent)  {
    var movieClip: bm = bm(event.target);
    this.removeChild(movieClip);
    removeChild(movieClip);
    movieClip = null;
    deletemain.removeEventListener(MouseEvent.CLICK, deleteMain);
}

Answer 1

好的，要了解為什么您的代碼不起作用，讓我們來看看它：

main.addEventListener(MouseEvent.CLICK, addMain);
function addMain(e: MouseEvent) 
{
    // here you are creating a local var "movieClip" 
    // inside your "addMain" function, so it's only accessible here
    var movieClip:bm = new bm();
        movieClip.x = 640;
        movieClip.y = 570;

    this.addChild(movieClip);

    main.removeEventListener(MouseEvent.CLICK, addMain);

    // I don't really know why you do this !
    deletemain.removeEventListener(MouseEvent.CLICK, addMain);
}

deletemain.addEventListener(MouseEvent.CLICK, deleteMain);
function deleteMain(e: MouseEvent)
{
    // here, you are creating a local var "movieClip"
    // by casting (converting) your "deletemain" button (e.target) to an "bm" object

    // event.target should be e.target
    var movieClip: bm = bm(event.target);

    // here your are removing the "deletemain" button, once
    this.removeChild(movieClip);
    // and twice
    removeChild(movieClip);

    movieClip = null;

    deletemain.removeEventListener(MouseEvent.CLICK, deleteMain);
}

因此，要執行您想要的操作：創建一個 MovieClip 並使用兩個按鈕將其刪除，您必須將“movieClip”聲明為一個全局變量，以便您的兩個偵聽器函數可以訪問它：

// declare a global "bm" object
var movieClip:bm;

btn_add.addEventListener(MouseEvent.CLICK, btn_add_onPress);
function btn_add_onPress(e: MouseEvent): void
{
    // create the "movieClip" object
    movieClip = new bm();
    addChild(movieClip);

    // remove the click event listener for the btn_add
    btn_add.removeEventListener(MouseEvent.CLICK, btn_add_onPress);
}

btn_delete.addEventListener(MouseEvent.CLICK, btn_delete_onPress);
function btn_delete_onPress(e:MouseEvent) : void 
{
    // remove the "movieClip" object
    removeChild(movieClip);
    movieClip = null;

    // remove the click event listener for the btn_delete
    btn_delete.removeEventListener(MouseEvent.CLICK, btn_delete_onPress);
}

希望能有所幫助。