本文实例为大家分享了Android自定义View实现水波纹效果的具体代码，供大家参考，具体内容如下
效果如下：
原理
控制代码
//这里用的kotlin
//主线程刷新控件
val mHandler = object : Handler() {
override fun handleMessage(msg: Message?) {
waterRippleView.refreshView()
}
//开启动画，开线程，延时刷新period值，画布进行x方向平移
private fun progressAdd() {
isAnimate = true
Thread(Runnable {
while (isAnimate) {
Thread.sleep(100)
mHandler.sendEmptyMessage(0)
}
}).start()
}
//停止动画
private fun progressReduce() {
isAnimate = false
}
控件源码：
//java编写
public class WaterRippleView extends View {
private float mWidth;
private float mHeight;
//总周期为2s
private int CIRCLE_PERIOD = 2000;
//振幅，波纹高度
private float ampltitude = 100;
//填充颜色
private int paintColor = 0xff57c011;
//当前时间值，累加并循环
private int period = 0;
private Paint paint;
private Path path;
public WaterRippleView(Context context) {
this(context, null);
}
public WaterRippleView(Context context, @Nullable AttributeSet attrs) {
this(context, attrs, 0);
}
public WaterRippleView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
paint = new Paint();
paint.setColor(paintColor);
paint.setStyle(Paint.Style.FILL);
paint.setAntiAlias(true);
path = new Path();
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mWidth = w;
mHeight = h;
}
public void refreshView() {
period += 100;
if (period > CIRCLE_PERIOD) period %= CIRCLE_PERIOD;
invalidate();
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//周期性的移动画布
float offsetX = mWidth / CIRCLE_PERIOD * period;
canvas.translate(-offsetX, 0);
path.reset();
//第一个正弦曲线
path.moveTo(0, mHeight / 2);
path.cubicTo(mWidth / 4, mHeight / 2 - ampltitude,
mWidth * 3 / 4, mHeight / 2 + ampltitude, mWidth, mHeight / 2);
//第二个正弦曲线
path.cubicTo(mWidth * 5 / 4, mHeight / 2 - ampltitude,
mWidth * 7 / 4, mHeight / 2 + ampltitude, 2 * mWidth, mHeight / 2);
//形成闭合路径
path.lineTo(2 * mWidth, mHeight);
path.lineTo(0, mHeight);
path.lineTo(0, mHeight / 2);
canvas.drawPath(path, paint);
}
}