android绘图Path类仿加速球水面波动效果

android提供的Path类，他可以预先在View上连成路径，然后调用Canvas的drawPath（path，paint），沿着路径画出来即可；
【1】画三角形

//        path.moveTo(100, 100);
//        path.lineTo(0, 200);
//        path.lineTo(200, 200);
//        path.close();//连接首尾
//        canvas.drawPath(path, paint);
//        canvas.drawTextOnPath("我沿着这条线走", path, 0, 0, paint);

【画贝塞尔曲线】

 //贝塞尔曲线

// path.moveTo(100,100);
// path.quadTo(100, 400, 300, 300);//两个点：控制点；结束点
// canvas.drawPath(path, paint);
//canvas.drawPoint(100, 100, paintPoint);
//canvas.drawPoint(100,400,paintPoint);
//canvas.drawPoint(300,300,paintPoint);

【仿水边波动效果】

public class MyPathView extends View {
    private Paint paint;
    private Path path;
    private Paint paintPoint;
    private int width;
    private int height;

    private int count = 0;
    private int size = 0;

    private boolean isAdd=true;
    private Handler handler = new Handler() {

        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);
            switch (msg.what){
                case 0x23:
                    count+=5;
                    if(count>=80){
                        count=0;
                    }
                    if (isAdd){
                        size++;
                        if(size>10){
                            isAdd = false;
                        }
                    }else{
                        size--;
                        if(size<=-10){
                            isAdd =true;
                        }
                    }
                    invalidate();
                    sendEmptyMessageDelayed(0x23,100);
                    break;
            }



        }
    };

    public MyPathView(Context context, AttributeSet attrs) {
        super(context, attrs);
        paint = new Paint();
        paint.setAntiAlias(true);
        paint.setTextSize(30);
        paint.setStyle(Paint.Style.STROKE);



        paintPoint = new Paint();
        paintPoint.setStrokeWidth(10);
        paintPoint.setColor(Color.GREEN);
        paintPoint.setStyle(Paint.Style.FILL);

        path = new Path();

        handler.sendEmptyMessageDelayed(0x23, 1000);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        path.reset();

        path.moveTo(count, 100);
        for (int i = 0; i < 10; i++) {
            path.rQuadTo(20, 20, 40, 0);
            path.rQuadTo(20, -20, 40, 0);

        }

        canvas.drawPath(path, paint);
        canvas.drawRect(200, 0, 400, 200, paint);

    }


    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        width = getDefaultSize(getSuggestedMinimumWidth(), widthMeasureSpec);
        height = getDefaultSize(getSuggestedMinimumHeight(), heightMeasureSpec);
        setMeasuredDimension(width, height);
    }
}

布局

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <com.example.administrator.canvas.widget.MyPathView
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>