Android RotateAnimation未按预期工作

Question

我想用这样的方式动画一个imageView：(三角定义的角度符号)

1. 从0到-45的平滑旋转
2. 从-45到+45的平滑旋转
3. 从+45到-45的平滑旋转
4. 重新启动到2(无限循环)

通过下面的代码，我得到：

1. 从0到+45的平滑旋转
2. 立即恢复到0
3. 从0到-45的平滑旋转
4. 从-45到0的平滑旋转
5. 重新启动到3(无限循环)

所以，完全不是我想要的！

有人知道如何解决这个问题吗？

谢谢！

这是我的代码：

float angle = 45f;

        RotateAnimation rotateAnimation1 = new RotateAnimation(0, -angle,
                Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);            
        rotateAnimation1.setStartOffset(0);
        rotateAnimation1.setDuration(2000);
        rotateAnimation1.setInterpolator(new LinearInterpolator());



        RotateAnimation rotateAnimation2 = new RotateAnimation(-angle, angle,
                Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
        //  animationSet.addAnimation(rotateAnimation);
        rotateAnimation2.setStartOffset(0);
        rotateAnimation2.setDuration(4000);
        rotateAnimation2.setInterpolator(new LinearInterpolator());



        RotateAnimation rotateAnimation3 = new RotateAnimation(angle, -angle,
                Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);       
        rotateAnimation3.setStartOffset(4000);
        rotateAnimation3.setDuration(4000);
        rotateAnimation3.setInterpolator(new LinearInterpolator());



        final AnimationSet animSet1 = new AnimationSet(true);
        animSet1.setFillEnabled(true);
        animSet1.addAnimation(rotateAnimation1);


        final AnimationSet animSet2 = new AnimationSet(true);
       // animSet2.setFillEnabled(true);
        animSet2.addAnimation(rotateAnimation2);
        animSet2.addAnimation(rotateAnimation3);


        animSet1.setAnimationListener(new Animation.AnimationListener() {
            @Override
            public void onAnimationStart(Animation animation) {

            }

            @Override
            public void onAnimationEnd(Animation animation) {

                view.startAnimation(animSet2);


            }

            @Override
            public void onAnimationRepeat(Animation animation) {
            }
        });


        animSet2.setAnimationListener(new Animation.AnimationListener() {
            @Override
            public void onAnimationStart(Animation animation) {

            }

            @Override
            public void onAnimationEnd(Animation animation) {

                view.startAnimation(animSet2);

            }

            @Override
            public void onAnimationRepeat(Animation animation) {
            }
        });





        view.startAnimation(animSet1);

Answer 1

视图返回为零的原因是视图的旋转属性没有更改。您应该在第一个动画结束后将旋转设置为视图，或者使用默认情况下设置视图旋转的ObjectAnimator.ofFloat(imageview ,"rotation", 0f, 360f);。

Answer 2

1.从0到-45的平滑旋转：倒转角符号和setFillAfter(true)因此视图保持结束动画位置

    RotateAnimation rotateAnimation1 = new RotateAnimation(0, 45f,
            Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f); 
    rotateAnimation1.setFillAfter(true); //This keeps view at animation ended position            
    rotateAnimation1.setStartOffset(0);
    rotateAnimation1.setDuration(2000);
    rotateAnimation1.setInterpolator(new LinearInterpolator());

2.从-45到+45的平滑旋转：将动画开始角设置为0，因为视图已经旋转。

    // Since view already is at -45 position due to rotateAnimation1.setFillAfter(true), now start point is 0 again
    RotateAnimation rotateAnimation2 = new RotateAnimation(0, -90,
            Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
    rotateAnimation2.setFillAfter(true);
    rotateAnimation2.setStartOffset(0);
    rotateAnimation2.setDuration(4000);
    rotateAnimation2.setInterpolator(new LinearInterpolator());

其余步骤按照上面的逻辑简单明了。