先看下效果，离我的想达到的效果还比较远

主要是原理是不断改变贝塞尔曲线的控制点(改变path即可)

效果为从百分之0到百分70然后改变颜色，水最终停留在 百分之20，百分比计算不准确的，只是大概而已

下面是源码，但是没有完善

package com.example.myapp;

import android.content.Context;

import android.graphics.*;

import android.util.AttributeSet;

import android.util.Log;

import android.view.View;

import android.widget.ImageView;

import java.lang.ref.WeakReference;

/**

* Created by jiangwj on 2015/3/18.

*/

public class WaveView extends ImageView {

private Paint mPaint;

private Xfermode mXfermode = new PorterDuffXfermode(PorterDuff.Mode.DST_IN);

private float waveY;//起始点以及重点的y

private float ctrolX,ctrolY;//控制点的y

private float mWidth,mHeight;

private Path mPath;// 路径对象

private boolean isAdd;//水平增加

private boolean isUp;//向上增加

private Bitmap markBitmap;

private boolean isAni=true;

private int distHeight;//目标高度

private float percent;//百分比

public WaveView(Context context, AttributeSet attrs) {

super(context, attrs);

mPaint = new Paint(Paint.ANTI_ALIAS_FLAG| Paint.DITHER_FLAG);

mPaint.setColor(0xcce1162e);

// 不使用硬件加速

setLayerType(LAYER_TYPE_SOFTWARE, null);

//mPaint.setMaskFilter(new EmbossMaskFilter(new float[] { 1, 1, 1F }, 0.1F, 0.1F, 10F));

mPaint.setMaskFilter(new BlurMaskFilter(10, BlurMaskFilter.Blur.SOLID));

mPath = new Path();

mXfermode=new PorterDuffXfermode(PorterDuff.Mode.DST_IN);

}

public void addAnimotion(){

percent= (float) (1-ctrolY/mHeight);

if(percent>=0.7f) {

mPaint.setColor(0xcc11ff24);

setDist(20);

}

if (ctrolX >= mWidth + 1 / 4F * mWidth) {

isAdd = false;

}else if (ctrolX <= -1 / 4F * mWidth) {

isAdd = true;

}

ctrolX = isAdd ? ctrolX + mWidth/10: ctrolX - mWidth/10;

changeHeight();

postInvalidate();

}

@Override

protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)

{

super.onMeasure(widthMeasureSpec, heightMeasureSpec);

/**

* 如果类型是圆形，则强制改变view的宽高一致

*/

int width = Math.min(getMeasuredWidth(), getMeasuredHeight());

setMeasuredDimension(width, width);

}

@Override

protected void onSizeChanged(int w, int h, int oldw, int oldh) {

super.onSizeChanged(w, h, oldw, oldh);

mWidth = w;

mHeight = h;

//控制点的Y,其实为高度为0

ctrolY = mHeight;

//起点终点的Y

waveY = ctrolY+mHeight/10;

setDist(70);

}

public void setPath(){

mPath.moveTo(-1 / 4F * mWidth, waveY);//起点

mPath.quadTo(ctrolX, ctrolY, mWidth + 1 / 4F * mWidth, waveY);//二阶贝塞尔曲线

mPath.lineTo(mWidth + 1 / 4F * mWidth, mHeight);

mPath.lineTo(-1 / 4F * mWidth, mHeight);

mPath.close();

}

@Override

protected void onDraw(Canvas canvas) {

if(markBitmap==null){

markBitmap=getMarkBitmap();

}

setPath();//生成图案路径

//图层

int sc = canvas.saveLayer(0, 0, mWidth, mHeight, null, Canvas.ALL_SAVE_FLAG);

canvas.drawPath(mPath, mPaint);//水波

mPaint.setXfermode(mXfermode);

canvas.drawBitmap(markBitmap,0,0,mPaint);

mPaint.setXfermode(null);

canvas.restoreToCount(sc);

mPath.reset();//重置图案路径

if(isAni){//是否开启动画

addAnimotion();

}

}

//设置当前百分比

public void setDist(int percent){

distHeight= (int) (mHeight*(100-percent)/100);

}

public void changeHeight(){

if(ctrolY

ctrolY +=1;

waveY += 1;

}

if(ctrolY>=distHeight){

ctrolY -=1;

waveY -= 1;

}

}

//覆盖层的圆形

public Bitmap getMarkBitmap()

{

Bitmap bitmap = Bitmap.createBitmap(getWidth(), getHeight(),

Bitmap.Config.ARGB_8888);

Canvas canvas = new Canvas(bitmap);

Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG| Paint.DITHER_FLAG);

paint.setColor(Color.BLACK);

// paint.setMaskFilter(new BlurMaskFilter(5, BlurMaskFilter.Blur.SOLID));

canvas.drawCircle(mWidth/2, mWidth/ 2, mWidth / 2, paint);

return bitmap;

}

}