波浪线,水波纹

自定义View

package gg.bw.com.wangshu20190404;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.Path;
import android.util.AttributeSet;
import android.view.View;

public class WaterView2 extends View {
    Paint paint = new Paint();

    Path path = new Path();
    float mt;
    public WaterView2(Context context) {
        super(context);
        paint.setAntiAlias(true);
    }

    public WaterView2(Context context,  AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        path.reset();
        path.moveTo(getLeft(),getBottom());
         float v = (float) (Math.PI *2/ getRight());
         mt-=0.1;
        for (int i = 0; i <=getRight() ; i+=20) {
            path.lineTo(i, (float) (10 * Math.cos(v * i +mt)+ 10));
        }
        path.lineTo(getRight(),getBottom());

        canvas.drawPath(path,paint);
        postInvalidateDelayed(20);


    }
}