Android贝塞尔曲线实现水波纹的效果

前两天朋友找我实现一个水波纹的效果，因为这块一直没做过，所以花了一上午时间研究一下，参考了网上的一些方法，得知Android还有Path.quadTo()这么一个方法。

话不多说，代码如下：

public class MyView extends View implements View.OnClickListener {    private int mRippleWeight;//一个波的周期长度    private  int mRippleCount;    private int mScreenWidth;    private int mScreenHeight;    private int mCenterY;//需要展示的位置中线    private int mOffset;    private Path mPath;    private Paint mPaint;    private ValueAnimator mValueAnimatior;    public MyView(Context context) {        super(context);    }    public MyView(Context context, AttributeSet attrs) {        super(context, attrs);        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);        mPaint.setStyle(Paint.Style.STROKE);//        mPaint.setStyle(Paint.Style.FILL_AND_STROKE);//如若需要下方带颜色可用此样式        mPaint.setStrokeWidth(8);        mPaint.setAntiAlias(true);        mPaint.setColor(Color.BLACK);    }    public MyView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);    }    @Override    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        super.onMeasure(widthMeasureSpec, heightMeasureSpec);        mPath = new Path();        mScreenHeight = getMeasuredHeight();        mScreenWidth = getMeasuredWidth();        mCenterY = mScreenWidth / 2;        mRippleWeight = mScreenHeight / 2;        mRippleCount = Math.round(mScreenWidth / mRippleWeight + 2);        setOnClickListener(this);    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        mPath.reset();//重置笔画        mPath.moveTo(-mRippleWeight,mCenterY);//波走完重新的起点        /**         * 如若波上下不够大，仅需修改mCenterY + 400及mCenterY - 400，         * 如若波左右不够大，请把mRippleWeight值变大         */        for (int i = 0;i <  mRippleCount;i++) {            mPath.quadTo(-mRippleWeight * 3 / 4 + i * mRippleWeight + mOffset,mCenterY + 100,-mRippleWeight / 2 + i * mRippleWeight + mOffset,mCenterY);            mPath.quadTo(-mRippleWeight / 4 + i * mRippleWeight + mOffset,mCenterY - 100,i * mRippleWeight + mOffset,mCenterY);        }        canvas.drawPath(mPath,mPaint);    }    @Override    public void onClick(View v) {        mValueAnimatior = ValueAnimator.ofInt(0, mRippleWeight);        mValueAnimatior.setDuration(800);        mValueAnimatior.setInterpolator(new LinearInterpolator());        mValueAnimatior.setRepeatCount(ValueAnimator.INFINITE);        mValueAnimatior.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {            @Override            public void onAnimationUpdate(ValueAnimator animation) {                mOffset = (int) animation.getAnimatedValue();                invalidate();            }        });        mValueAnimatior.start();    }} 当然觉得还不明白的可以下载我写的一个demo，链接如下：http://download.csdn.net/download/qq_28767927/9897370

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