思路:

1.基于时间的显示映射。如:给定度数,显示圆弧,加上时序,即可有圆弧动画的效果

2.给定时序。用于驱动动画的一帧帧绘制

方案一、基于ObjectAnimator。动画运作时会调用degree对应set函数(基于放射调用),即setDegree。

ObjectAnimator ani=ObjectAnimator.ofInt(myView, "degree", 0,300);
ani.start();

注:1>混编后,默认会将setDegree混掉,导致找不到函数,故混编后这种机制会失效。解决方法是1.proguard中防止该段代码混编(具体方法百度) 2.使用方法二

     2>ObjectAnimator在3.0后才支持,可使用NineOldAndroids库,效果完全一样。

方案二、仍然基于ObjectAnimator。但基于回调,这种方法未用到反射,故混编时仍ok

ObjectAnimator ani=ObjectAnimator.ofInt(myView, new Prop(), 0,300);
ani.start();

class Prop extends Property<View, Integer> {				public Prop() {			// TODO Auto-generated constructor stub			super(Integer.class, "kk");		}				@Override		public void set(View object, Integer value) {			// TODO Auto-generated method stub			((MyView1)object).setDegree(value);		}				@Override		public Integer get(View object) {			// TODO Auto-generated method stub			return null;		}	};

方案三、用animation提供时序。interpolatedTime为0~1,即时间的百分比。

Animation ani=new Animation() {				@Override				protected void applyTransformation(float interpolatedTime,						Transformation t) {					// TODO Auto-generated method stub					myView.setDegree((int)(interpolatedTime*300f));				}			};			ani.setDuration(3000);			myView.startAnimation(ani);

//===========================================================================

自定义视图,setDegress可改变圆弧角度:

private class MyView1 extends ImageView {		public int degree = 0;		public MyView1(Context ct) {			// TODO Auto-generated constructor stub			super(ct);		}				@Override		protected void onDraw(Canvas canvas) {			// TODO Auto-generated method stub			super.onDraw(canvas);			Rect r = new Rect();			getLocalVisibleRect(r);			canvas.drawArc(new RectF(r), 0, degree, true, pt);		}		public void setDegree(int degree) {			this.degree = degree;			invalidate();		}	}

效果: