水

package com.bwie.guilin.demolian;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;

public class WaterView extends View {

private Paint mPaintTop;
private Paint mPaintBottom;
private Path mPathTop;
private Path mPathBottom;
private float φ;
private int topcolor,bottomcolor;


public WaterView(Context context) {
    super(context);
    init(context);
}


public WaterView(Context context, @Nullable AttributeSet attrs) {
    super(context, attrs);
    TypedArray ty = context.obtainStyledAttributes(attrs, R.styleable.WaterView);
    topcolor = ty.getColor(R.styleable.WaterView_topcolor, Color.WHITE);
    bottomcolor = ty.getColor(R.styleable.WaterView_bottom, Color.WHITE);
    ty.recycle();
    init(context);
}

public WaterView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    init(context);
}

private void init(Context context) {
    mPaintTop = new Paint();
    mPaintTop.setColor(topcolor);
    mPaintTop.setAntiAlias(true);
    mPaintBottom = new Paint();

    mPaintBottom.setColor(bottomcolor);
    mPaintBottom.setAntiAlias(true);
    mPaintBottom.setAlpha(60);
    mPathTop = new Path();
    mPathBottom = new Path();

}


//绘制
@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    mPathTop.reset();
    mPathBottom.reset();
    //路径起始的位置
    mPathTop.moveTo(getLeft(), getBottom());
    mPathBottom.moveTo(getLeft(), getBottom());
    //获取每个宽度所占的度数
    double mY = Math.PI * 2 / getWidth();
    //从左往右
    φ -= 0.1f;

    //路径移动的坐标
    for (float x = 0; x <= getWidth(); x += 20) {
        float y = (float) (10 * Math.cos(mY * x + φ)+10);
        mPathTop.lineTo(x, y);
        mPathBottom.lineTo(x, (float) (10 * Math.sin(mY * x + φ)));
        listener.ann(y);
    }


    //路径终止的位置
    mPathTop.lineTo(getRight(), getBottom());
    mPathBottom.lineTo(getRight(), getBottom());

    canvas.drawPath(mPathTop, mPaintTop);
    canvas.drawPath(mPathBottom, mPaintBottom);
    //更新ui
    postInvalidateDelayed(20);

}

private AListener listener;

public void getListener(AListener listener) {
    this.listener = listener;
}

//传递y值
public interface AListener {
    void ann(float y);
}

}

在 Activitivity里面获取

package com.bwie.guilin.demolian;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    final ImageView logo = (ImageView) findViewById(R.id.logo);
    WaterView waterView = (WaterView) findViewById(R.id.wave_view);
    final RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) logo.getLayoutParams();
    waterView.getListener(new WaterView.AListener() {
        @Override
        public void ann(float y) {
            params.setMargins(0, 0, 0, (int) y);
            logo.setLayoutParams(params);
        }
    });
}

}