Question

我正在使用我的应用中的一些图片制作相对布局的动画。当我编写代码以在按钮单击时为布局设置动画，这是第一次显示不是动画。然后在同一个按钮上单击我向上滑动布局。之后，如果我单击按钮滑动动画工作正常。实际上我必须在onCreate本身而不是按钮点击内写下这个滑动动画。以下是我的代码。谁能告诉我为什么它没有显示动画？

   protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.fadeview);
        iconLayout=(RelativeLayout)findViewById(R.id.icon_ayout);
        iconLayout.postDelayed(new Runnable() {

            @Override
            public void run() {
                // TODO Auto-generated method stub

                iconLayout.setVisibility(View.VISIBLE);
                SlideToDown();
            }
        }, 500);
   }

 public void SlideToAbove() {
        Animation slide = null;

        slide=new TranslateAnimation(0.0f, 0.0f, 0.0f,-iconLayout.getHeight());
        slide.setDuration(1000);
        slide.setFillAfter(true);
        slide.setFillEnabled(true);
        iconLayout.startAnimation(slide);

        slide.setAnimationListener(new AnimationListener() {

            @Override
            public void onAnimationStart(Animation animation) {

            }

            @Override
            public void onAnimationRepeat(Animation animation) {
            }

            @Override
            public void onAnimationEnd(Animation animation) {

                iconLayout.clearAnimation();

                RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
                        iconLayout.getWidth(), iconLayout.getHeight());
                // lp.setMargins(0, 0, 0, 0);
                //lp.addRule(RelativeLayout.ALIGN_PARENT_TOP);
                iconLayout.setLayoutParams(lp);

            }

        });

    }
 public void SlideToDown() {
        Animation slide = null;

        slide=new TranslateAnimation(0.0f, 0.0f, -iconLayout.getHeight(), 0.0f);

        slide.setDuration(1000);
        slide.setFillAfter(true);
        slide.setFillEnabled(true);
        iconLayout.startAnimation(slide);

        slide.setAnimationListener(new AnimationListener() {

            @Override
            public void onAnimationStart(Animation animation) {

            }

            @Override
            public void onAnimationRepeat(Animation animation) {
            }

            @Override
            public void onAnimationEnd(Animation animation) {

                iconLayout.clearAnimation();

                RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(
                        iconLayout.getWidth(), iconLayout.getHeight());
                lp.setMargins(0,0, 0, 0);
                lp.addRule(RelativeLayout.ALIGN_PARENT_TOP);
                iconLayout.setLayoutParams(lp);

            }

        });

    }

Answer 1

这是因为你在onCreate（）中开始动画，并且此时视图可用，但实际上并没有绘制（没有宽度和高度）。这里iconLayout.getHeight()的值将返回值0.

解决方案是将Layoutlistener设置为视图，并且侦听器在绘制时会告诉您。之后，您可以开始动画。

ViewTreeObserver loadingObserver = iconLayout.getViewTreeObserver();
loadingObserver.addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
    @Override
    public void onGlobalLayout() {
        iconLayout.getViewTreeObserver().removeGlobalOnLayoutListener(this);
        SlideToDown();
    }
});

查看向下滑动动画不工作

1 个答案: