自定义View实现波浪

新建一个工具类
继承View实现 onMeasure（） onLayout（） OnDraw（）三个方法
具体实现如下：
public class Views extends View {
private Paint paint;
private Path path;
float A=8f;
float w;
float k=0f;
float f;
float y;
private Paint paint1;
private Path path1;
float y1;
public Views(Context context) {
super(context);
initView();
}

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

public Views(Context context, AttributeSet attrs, int defStyleAttr) {
    super(context, attrs, defStyleAttr);
    initView();
}
private void initView(){
    //创建一个画笔
    paint=new Paint(Paint.ANTI_ALIAS_FLAG);
    paint.setColor(Color.WHITE);
    paint.setAntiAlias(true);
    paint.setStyle(Paint.Style.FILL);
    path=new Path();
    //创建一个画笔
    paint1=new Paint(Paint.ANTI_ALIAS_FLAG);
    paint1.setColor(Color.BLUE);
    paint1.setAntiAlias(true);
    paint1.setStyle(Paint.Style.FILL);
    paint1.setAlpha(80);
    path1=new Path();
}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    path.reset();
    path1.reset();
    path.moveTo(getLeft(),getBottom());
    path1.moveTo(getLeft(),getBottom());
    w= (float) (2*Math.PI/getWidth());
    f-=0.1f;
    for (int x=0;x<=getWidth();x+=20){
        y= (float) (A*Math.sin(w*x+f));
        y1= (float) (A*Math.cos(w*x+f)+8);

        path.lineTo(x,y);
        path1.lineTo(x,y1);
        animations.getY(y);


    }
    path.lineTo(getRight(),getBottom());
    path1.lineTo(getRight(),getBottom());
    canvas.drawPath(path,paint);
    canvas.drawPath(path1,paint1);
    postInvalidateDelayed(20);
}

private Animations animations;


public void setAnimations(Animations animations) {
   this.animations= animations;
}

public interface Animations{
    void getY(float y);
}

}

主页面布局
<FrameLayout
android:layout_width=“match_parent”
android:layout_height=“300dp”

    android:layout_alignParentTop="true">

    <ImageView
        android:id="@+id/image"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginStart="122dp"
        android:layout_marginLeft="122dp"
        android:layout_marginTop="14dp"
        android:src="@drawable/ic_launcher_background" />

    <com.bwie.wo.wangshuilong20190308.view.activity.Views
        android:id="@+id/views"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_marginTop="155dp" />

</FrameLayout>

MainActivity

initView（）；

private void initView(){
lp=new FrameLayout.LayoutParams(-2,-2);
lp.gravity=Gravity.CENTER;
views.setAnimations(new Views.Animations() {
@Override
public void getY(float y) {
lp.setMargins(0,-20,0, (int) (y+2));
imageView.setLayoutParams(lp);
}
});
}