如何在Android的画布上画圆角线条

public class RoundedLineView extends View {
    private Paint paint;
    private Path path;

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

    public RoundedLineView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
        init();
    }

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

    private void init() {
        paint = new Paint();
        paint.setColor(Color.BLACK);
        paint.setStrokeWidth(5);
        paint.setStyle(Paint.Style.STROKE);
        paint.setAntiAlias(true);

        path = new Path();
    }

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

        int width = getWidth();
        int height = getHeight();

        // 设置路径起点
        path.moveTo(0, height / 2);

        // 绘制圆角线条
        path.lineTo(width, height / 2);
        path.arcTo(new RectF(width - height, 0, width, height), 90, 180);

        canvas.drawPath(path, paint);
    }
}

<com.example.RoundedLineView
    android:layout_width="match_parent"
    android:layout_height="200dp" />