在android中旋转动画的缓动效果

时间:2014-08-22 09:03:03

标签: android animation rotation android-animation easing

我正在研究用于轮盘游戏的旋转轮的动画,因为我希望轮子像真正的旋转一样旋转(例如,轮子旋转速度应该慢慢地开始然后快速地停止)

我知道我应用的基本旋转动画,下面是我的动画XML文件代码:

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:interpolator="@android:anim/linear_interpolator">
<rotate
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:fromDegrees="0"
    android:toDegrees="360"
    android:duration="200"
    android:repeatMode="restart"
    android:repeatCount="-1"
    android:pivotX="50%"
    android:pivotY="50%">
</rotate>  

和活动:

public class RouletteActivity extends Activity {

Button button_spin;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_roulette);
   button_spin = (Button)findViewById(R.id.btn_spin);
   button_spin.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View arg0) {
            // TODO Auto-generated method stub


            StartLoading();

            Handler handler = new Handler(); 
            handler.postDelayed(new Runnable() { 
                public void run() {
                    StopLoading();
                } 
            }, 5000);

        }
    });
}

 public void StartLoading() {
    ImageView img_wheel = (ImageView) this.findViewById(R.id.imageView1);
    img_wheel.setImageDrawable(getResources().getDrawable(R.drawable.wheel));
    Animation rotateLoading = AnimationUtils.loadAnimation(this, R.anim.rotate);
    img_wheel.clearAnimation();
    img_wheel.setAnimation(rotateLoading);
}


 public void StopLoading() {
    ImageView img_wheel = (ImageView) this.findViewById(R.id.imageView1);
    if (img_wheel.getAnimation() != null)
    {
        img_wheel.clearAnimation();
        img_wheel.setImageDrawable(getResources().getDrawable(R.drawable.wheel));

    }
}

请帮助我实现我想要的动画,谢谢。

1 个答案:

答案 0 :(得分:3)

您可以通过Interpolator应用动画来修改动画的行为 AccelerateDecelerateInterpolator似乎是最好的。

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:interpolator="@android:anim/accelerate_decelerate_interpolator">
<rotate
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:fromDegrees="0"
    android:toDegrees="360"
    android:duration="200"
    android:repeatMode="restart"
    android:repeatCount="-1"
    android:pivotX="50%"
    android:pivotY="50%">
</rotate>
</set>

或者更简单:

yourView.animate().rotation(value).setInterpolator(new AccelerateDecelerateInterpolator()).start();