在Android视图中绘制一个虚线圆圈

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

public class CircleView extends View {
    private int radius;
    private Paint paint;

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

    public CircleView(Context context, int radius) {
        super(context);
        this.radius = radius;
        init();
    }

    private void init() {
        paint = new Paint();
        paint.setAntiAlias(true);
        paint.setStrokeWidth(2);
        paint.setStyle(Paint.Style.STROKE);
        paint.setColor(Color.WHITE);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        Path path = new Path();
        path.addCircle(getWidth() / 2, getHeight() / 2, radius, Path.Direction.CW);
        canvas.clipPath(path);
        canvas.drawCircle(getWidth() / 2, getHeight() / 2, radius - 2, paint);
    }
}