android自定义view实现圆周运动

本文实例为大家分享了android自定义view实现圆周运动的具体代码，供大家参考，具体内容如下

思想

自定义Animation，自己定义半径，相当于原来控件的位置为（0,0），按照每个角度区间，计算新的位置，跟着时间变动

逆时针转动

public class VenusCircleAnimation extends Animation {

  private int radii;
  public VenusCircleAnimation(int radii) {
    this.radii = radii;
  }

  @Override
  protected void applyTransformation(float interpolatedTime, Transformation t) {
    //根据取值范围 确定圆周运动的角度范围。360-0
    float d = 360 * interpolatedTime;//interpolatedTime 取值范围 0-1,表示时间
    if (d > 360) { //算法二
      d = d-360;
    }
    int[] ps = getNewLocation((int) d, radii);//
    t.getMatrix().setTranslate(ps[0], ps[1]);
  }

  public int[] getNewLocation(int newAngle, int r) {
    int newAngle1;
    int newX = 0, newY = 0;
    if (newAngle >= 0 && newAngle <= 90) {
      // Math.PI/180得到的结果就是1°，然后再乘以角度得到角度
      newX = (int) ( - (r * Math.cos(newAngle * Math.PI / 180)));
      newY = (int) (r * Math.sin(newAngle * Math.PI / 180));
    } else if (newAngle >= 90 && newAngle <= 180) {// 90-180
      newAngle1 = 180 - newAngle;
      newX = (int) (r * Math.cos(newAngle1 * Math.PI / 180));
      newY = (int) (r * Math.sin(newAngle1 * Math.PI / 180));
    } else if (newAngle >= 180 && newAngle <= 270) {//180-270
      newAngle1 = 270 - newAngle;
      newX = (int) (r * Math.sin(newAngle1 * Math.PI / 180));
      newY = (int) ( - (r * Math.cos(newAngle1 * Math.PI / 180)));
    } else if (newAngle >= 270) {//270-360
      newAngle1 = 360 - newAngle;
      newX = (int) ( - (r * Math.cos(newAngle1 * Math.PI / 180)));
      newY = (int) ( - (r * Math.sin(newAngle1 * Math.PI / 180)));
    }
    return new int[]{newX, newY};
  }

}

顺时针

public class CircleAnimation extends Animation {

  private int radii;

  public CircleAnimation(int radii) {
    this.radii = radii;
  }

  @Override
  protected void applyTransformation(float interpolatedTime, Transformation t) {
    float d = 360 * interpolatedTime ;
    if (d > 360) {
      d = d - 360;
    }
    int[] ps = getNewLocation((int) d, radii);//
    t.getMatrix().setTranslate(ps[0], ps[1]);
  }

  public int[] getNewLocation(int newAngle, int r) {
    int newAngle1;
    int newX = 0, newY = 0;
    if (newAngle >= 0 && newAngle <= 90) {
      newX = (int) (r * Math.sin(newAngle * Math.PI / 180));
      newY = (int) ( - (r * Math.cos(newAngle * Math.PI / 180)));
    } else if (newAngle >= 90 && newAngle <= 180) {// 90-180
      newAngle1 = 180 - newAngle;
      newX = (int) (r * Math.sin(newAngle1 * Math.PI / 180));
      newY = (int) (r * Math.cos(newAngle1 * Math.PI / 180));
    } else if (newAngle >= 180 && newAngle <= 270) {//180-270
      newAngle1 = 270 - newAngle;
      newX = (int) ( - (r * Math.cos(newAngle1 * Math.PI / 180)));
      newY = (int) (r * Math.sin(newAngle1 * Math.PI / 180));
    } else if (newAngle >= 270 && newAngle <= 360) {//270-360
      newAngle1 = 360 - newAngle;
      newX = (int) ( - (r * Math.sin(newAngle1 * Math.PI / 180)));
      newY = (int) ( - (r * Math.cos(newAngle1 * Math.PI / 180)));
    }
    return new int[]{newX, newY};
  }
}

使用

CircleAnimation animationw = new CircleAnimation(m);
 animationw.setDuration(d);
 animationw.setRepeatCount(-1);
 animationw.setInterpolator(new LinearInterpolator());
 imageView.startAnimation(animationw);

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