您可以制作自定义视图和自定义动画。覆盖自定义动画中的applyTransformation() 方法以应用转换。
public class ArcView extends View {
private final Paint mPaint;
private final RectF mRect;
private float arcAngle;
public ArcView(Context context, AttributeSet attrs) {
super(context, attrs);
// Set Angle to 0 initially or whatever you want
arcAngle = 0;
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(4);
mPaint.setColor(Color.WHITE);
mRect = new RectF(2, 2, 78, 78);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawArc(mRect, 90, arcAngle, false, mPaint);
}
public float getArcAngle() {
return arcAngle;
}
public void setArcAngle(float arcAngle) {
this.arcAngle = arcAngle;
}
}
这是你的动画类的样子
public class ArcAngleAnimation extends Animation {
private ArcView arcView;
private float oldAngle;
private float newAngle;
public ArcAngleAnimation(ArcView arcView, int newAngle) {
this.oldAngle = arcView.getArcAngle();
this.newAngle = newAngle;
this.arcView = arcView;
}
@Override
protected void applyTransformation(float interpolatedTime, Transformation transformation) {
float angle = oldAngle + ((newAngle - oldAngle) * interpolatedTime);
arcView.setArcAngle(angle);
arcView.requestLayout();
}
public void setNewAngle(int newAngle){
this.newAngle = newAngle;
}
public void setOldAngle(float oldAngle) {
this.oldAngle = oldAngle;
}
}
现在您需要做的就是应用动画并在您的活动或片段中运行它
ArcView view = (ArcView) findViewById(R.id.arc_view);
ArcAngleAnimation arcAnimation;
arcAnimation = new ArcAngleAnimation(view, 30);
arcAnimation.setFillAfter(true);
arcAnimation.setDuration(200);
view.startAnimation(arcAnimation);