Android自定义View实现水波纹效果

public class WaveView extends View {

 private static final String TAG = "WaveView";

 private int waveColor;

 private int waveCount;

 private Bitmap waveCenterIcon;

 private Paint paint;

 private int mWidth;

 private int mHeight;

 private int centerX;

 private int centerY;

 private float radius; // 最外圆半径，即最大半径

 private float innerRadius; // 最内圆的半径，即最小半径

 private int centerIconWidth;

 private int centerIconHeight;

 private float[] waveDegreeArr;

 private boolean isRunning = true;

 public WaveView(Context context) {
  this(context, null);
 }

 public WaveView(Context context, AttributeSet attrs) {
  super(context, attrs);
  readAttrs(context, attrs);
  init();
 }

 private void init() {
  paint = new Paint(Paint.ANTI_ALIAS_FLAG);
  paint.setColor(waveColor);
  paint.setStyle(Paint.Style.FILL);
  waveDegreeArr = new float[waveCount];

  // 设置中间 drawable 点击事件


 }

 private void readAttrs(Context context, AttributeSet attrs) {
  TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.WaveView);
  try {
   waveColor = typedArray.getColor(R.styleable.WaveView_waveColor, 0xffff0000);
   waveCount = typedArray.getInt(R.styleable.WaveView_waveCount, 4);
   Drawable centerDrawable = typedArray.getDrawable(R.styleable.WaveView_waveCenterIcon);
   waveCenterIcon = ((BitmapDrawable) centerDrawable).getBitmap();
  } catch (Exception e) {

  } finally {
   typedArray.recycle();
  }
 }

 @Override
 protected void onSizeChanged(int w, int h, int oldw, int oldh) {
  super.onSizeChanged(w, h, oldw, oldh);
  mWidth = w;
  mHeight = h;
  centerX = mWidth / 2;
  centerY = mHeight / 2;
  radius = Math.min(mWidth, mHeight) / 2f;
  centerIcOnWidth= waveCenterIcon.getWidth();
  centerIcOnHeight= waveCenterIcon.getHeight();
  innerRadius = Math.max(centerIconWidth, centerIconHeight) * 1.2f;

  for (int i = 0; i  radius) {
    waveDegreeArr[i] = innerRadius;
   }
  }
  if (isRunning) {
   postInvalidateDelayed(50);
  }
 }

 private void drawCenterIcon(Canvas canvas) {
  paint.setAlpha(255);
  int left = centerX - centerIconWidth / 2;
  int top = centerY - centerIconHeight / 2;
  canvas.drawBitmap(waveCenterIcon, left, top, paint);
 }

 @Override
 public boolean onTouchEvent(MotionEvent event) {
  switch (event.getAction()) {
   case MotionEvent.ACTION_UP:
    // 处理事件逻辑
    handleEvent(event);
    return true;
  }
  return true;
 }

 private void handleEvent(MotionEvent event) {
  float touchX = event.getX();
  float touchY = event.getY();
  Log.i(TAG, "handleEvent: " + "(" + touchX + "," + touchY + ")");
  float distanceX = Math.abs(touchX - centerX);
  float distanceY = Math.abs(touchY - centerY);
  // 计算触摸点距离中心点的距离
  float distance = (float) Math.sqrt(distanceX * distanceX + distanceY * distanceY);
  // 当点击的点距离中心点距离小于最内圆半径时，认为是点击有效，否则无效
  if (distance