Android使用自定义view在指定时间内匀速画一条直线的实例代码

public class UniformLine extends View { 
 private int x, y, nextX, nextY, incrementY, incrementX; 
 public UniformLine(Context context) { 
 super(context); 
 } 
 public UniformLine(Context context, int x, int y, int nextX, int nextY) { 
 super(context); 
 this.x = x; 
 this.y = y; 
 this.nextX = nextX; 
 this.nextY = nextY; 
 init(); 
 } 
 private void init() { 
 p = new Paint(); 
 p.setColor(Color.WHITE); 
 p.setAntiAlias(true); 
 p.setStrokeWidth(4.0f); 
 
 ValueAnimator valueAnimatorX = ValueAnimator.ofFloat(x, nextX); 
 valueAnimatorX.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { 
  @Override 
  public void onAnimationUpdate(ValueAnimator animation) { 
  incrementX = Math.round((Float) animation.getAnimatedValue()); 
  invalidate(); 
  } 
 }); 
 ValueAnimator valueAnimatorY = ValueAnimator.ofInt(y, nextY); 
 valueAnimatorY.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { 
  @Override 
  public void onAnimationUpdate(ValueAnimator animation) { 
  incrementY = (int) animation.getAnimatedValue(); 
  invalidate(); 
  } 
 }); 
 AnimatorSet animatorSet = new AnimatorSet(); 
 LinearInterpolator ll = new LinearInterpolator(); 
 animatorSet.setInterpolator(ll);//匀速 
 animatorSet.setDuration(2000); 
 animatorSet.playTogether(valueAnimatorX, valueAnimatorY); 
 animatorSet.start(); 
 } 
 Paint p; 
 @Override 
 protected void onDraw(Canvas canvas) { 
 super.onDraw(canvas); 
 canvas.drawLine(Util.Div(Math.round(x)), Util.Div(Math.round(y)), 
  Util.Div(Math.round(incrementX)), Util.Div(Math.round(incrementY)), p);// 斜线 
 } 
} 

uniformLine = new UniformLine(mContext, 300, 500, 600, 200); 
addView(uniformLine);