Question

我想用淡入/淡出动画每10秒更改一次相对布局的背景。所以我找到了

//Transitiondrawable
TransitionDrawable transition = (TransitionDrawable) viewObj.getBackground();
transition.startTransition(transitionTime);

但它只支持2个Drawable，我想添加更多有没有办法做到这一点？

Answer 1

您可以创建自己的循环，例如：

 int delayBetweenAnimations = 10000;

    for (int i = 0; i < yourImagesArray.length ; i++) {

        int delay = i * delayBetweenAnimations;

        yourImageview.postDelayed(new Runnable() {
            @Override
            public void run() {
                //set your image and animation here
            }
        }, delay);

    }

另一种方法是使用递归动画：

          @Override    
           public void onAnimationEnd(Animator animation) {
               if(check_if_you_Still_want to_loop){
                    //rerun your animation
               }
           }

Answer 2

首先实现MyAnim.java类，如下所示：

public class MyAnim extends Animation {


    private final RelativeLayout view;
    private int targetBackGround;


    public MyAnim(RelativeLayout view, int tagetBackGroundColor) {
        this.view = view;
        this.targetBackGround = tagetBackGroundColor;
    }
    @Override
    protected void applyTransformation(float interpolatedTime, Transformation t) {
        super.applyTransformation(interpolatedTime, t);
        view.setBackgroundColor(targetBackGround);
    }


    public void setColor(int color) {
        this.targetBackGround = color;
    }
}

然后将以下代码添加到您的活动中，并在任何地方调用animateBackground（）方法：

    private MyAnim backgroundAnim;
    private int i;

    private void animateBackground(){
        final RelativeLayout animLay = (RelativeLayout) findViewById(R.id.animLay);
        final int colors[] = new int[]{Color.RED, Color.CYAN, Color.DKGRAY, Color.GREEN, Color.MAGENTA};
        backgroundAnim = new MyAnim(animLay, colors[i]);
        backgroundAnim.setDuration(1000);
        animLay.startAnimation(backgroundAnim);

        backgroundAnim.setAnimationListener(new Animation.AnimationListener() {
            @Override
            public void onAnimationStart(Animation animation) {

            }

            @Override
            public void onAnimationEnd(Animation animation) {

                if (i == colors.length - 1) {
                    i = 0;
                } else {
                    i++;
                }
                backgroundAnim.setColor(colors[i]);
                animLay.startAnimation(backgroundAnim);


            }

            @Override
            public void onAnimationRepeat(Animation animation) {

            }
        });
    }

如何更改每个android背景???秒？

2 个答案: