Android实现水波纹控件的方法

<?xml version="1.0" encoding="utf-8"?><resources> <declare-styleable name="waveStyleable">  <!-- 水波纹的长度-->  <attr name="waveLength" format="float"></attr>  <!-- 水波纹的高度-->  <attr name="waveHeight" format="float"></attr>  <!-- 水波纹的速度-->  <attr name="waveSpeed" format="float"></attr>  <!--水波纹上方的头像 -->  <attr name="waveTopIcon" format="reference"></attr>  <!--水波的颜色 -->  <attr name="waveColor" format="color"></attr>  <!--水波距离底部的距离 -->  <attr name="distanceY" format="float"></attr> </declare-styleable></resources>

public class WaveView extends View { private Paint paint; private Path path; private float waveLength ; private float waveHeight ; private float waveSpeed ; private Bitmap bitmap; private int waveColor ; private int strokeWidth = 3; private Region region; private int width,height; public int translateX ; private float distanceY; public WaveView(Context context) {  super(context); } public WaveView(Context context, AttributeSet attrs) {  super(context, attrs);  TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.waveStyleable);  waveLength = array.getFloat(R.styleable.waveStyleable_waveLength,300);  waveColor = array.getColor(R.styleable.waveStyleable_waveColor,0x00ff00);  waveHeight = array.getFloat(R.styleable.waveStyleable_waveHeight,100);  waveSpeed = array.getFloat(R.styleable.waveStyleable_waveSpeed,5);  distanceY = array.getFloat(R.styleable.waveStyleable_distanceY,100);  Drawable waveTopICon = array.getDrawable(R.styleable.waveStyleable_waveTopIcon);  array.recycle();  bitmap = drawableToBitmap(waveTopICon);  initPaint();  startAnimal(); } private void initPaint() {  paint = new Paint();  paint.setStyle(Paint.Style.FILL);  paint.setColor(waveColor);  paint.setStrokeWidth(strokeWidth);  //绘制贝塞尔曲线的path  path = new Path(); } @Override protected void onDraw(Canvas canvas) {  super.onDraw(canvas);  //绘制贝塞尔曲线  drawPath(canvas,path);  //绘制wave上部的头像  drawIcon(canvas); } private void drawIcon(Canvas canvas) {  float baseLine = height-distanceY;  if(region.getBounds().top==baseLine){   canvas.drawBitmap(bitmap,width/2-bitmap.getWidth()/2,region.getBounds().bottom-bitmap.getHeight(),paint);  }else {   if(region.getBounds().top==0){    canvas.drawBitmap(bitmap,width/2-bitmap.getWidth()/2,height-bitmap.getHeight()-distanceY,paint);   }   canvas.drawBitmap(bitmap,width/2-bitmap.getWidth()/2,region.getBounds().top-bitmap.getHeight(),paint);  } } private void drawPath(Canvas canvas, Path path) {  path.reset();  //path的起始点，向手机外多绘制一段  path.moveTo(-2* waveLength +translateX,getHeight()-distanceY);  for(int i = 0; i<getWidth()+ waveLength; i+= waveLength){   path.rQuadTo(waveLength /2,-waveHeight, waveLength,0);   path.rQuadTo(waveLength /2,waveHeight, waveLength,0);  }  region = new Region();  Region clip = new Region();  clip.set((int) (getWidth()/2-0.1),0,getWidth()/2,getHeight()*2);  region.setPath(path,clip);  path.lineTo(getWidth(),getHeight());  path.lineTo(-waveLength,getHeight());  path.close();  canvas.drawPath(path,paint); } public void startAnimal(){  ValueAnimator animator = ValueAnimator.ofFloat(0,1);  animator.setDuration(3000);  animator.setRepeatCount(ValueAnimator.INFINITE);  animator.setInterpolator(new LinearInterpolator());  animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {   @Override   public void onAnimationUpdate(ValueAnimator animation) {    translateX += waveSpeed;    if(-2* waveLength +translateX >= 0){     translateX = 0;    }    postInvalidate();   }  });  animator.start(); } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {  super.onMeasure(widthMeasureSpec, heightMeasureSpec);  //获取宽高模式  int widthMode = MeasureSpec.getMode(widthMeasureSpec);  int heightMode = MeasureSpec.getMode(heightMeasureSpec);  width = MeasureSpec.getSize(widthMeasureSpec);  height = MeasureSpec.getSize(heightMeasureSpec);  if (widthMode == MeasureSpec.AT_MOST){   width = (int) waveLength;  }  if(heightMode == MeasureSpec.AT_MOST){   height = (int) (waveHeight+ distanceY+bitmap.getHeight());  }  setMeasuredDimension(width,height); } /**  * dp转化为px  * @param dpValue  * @param context  * @return  */ public float dp2px(float dpValue,Context context){  return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,dpValue,context.getResources().getDisplayMetrics()); } /**  * 如果图片底部有很多空白会导致图片不能贴到波纹底部  * @param bitmap  * @return  */ public Bitmap makeRoundCorner(Bitmap bitmap) {  int width = bitmap.getWidth();  int height = bitmap.getHeight();  int left = 0, top = 0, right = width, bottom = height;  float roundPx = height/2;  if (width > height) {   left = (width - height)/2;   top = 0;   right = left + height;   bottom = height;  } else if (height > width) {   left = 0;   top = (height - width)/2;   right = width;   bottom = top + width;   roundPx = width/2;  }  Bitmap output = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);  Canvas canvas = new Canvas(output);  int color = 0xff424242;  Paint paint = new Paint();  Rect rect = new Rect(left, top, right, bottom);  RectF rectF = new RectF(rect);  paint.setAntiAlias(true);  canvas.drawARGB(0, 0, 0, 0);  paint.setColor(color);  canvas.drawRoundRect(rectF, roundPx, roundPx, paint);  paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));  canvas.drawBitmap(bitmap, rect, rect, paint);  return output; } public Bitmap drawableToBitmap(Drawable drawable) {  Bitmap bitmap = Bitmap.createBitmap(    drawable.getIntrinsicWidth(),    drawable.getIntrinsicHeight(),    drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888      : Bitmap.Config.RGB_565);  Canvas canvas = new Canvas(bitmap);  drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());  drawable.draw(canvas);  return makeRoundCorner(bitmap); }}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.iwintrue.waveapplication.MainActivity"> <com.iwintrue.waveapplication.WaveView xmlns:app="http://schemas.android.com/apk/res-auto" app:waveLength = "200" app:waveHeight = "50" app:waveSpeed = "10" app:waveColor = "#0ff" app:distanceY = "100" app:waveTopIcon = "@mipmap/icon" android:layout_centerInParent="true" android:id="@+id/waterView" android:layout_width="match_parent" android:layout_height="wrap_content" android:background="#f00" /></RelativeLayout>