在安卓系统的分隔线上添加圆形TextView或按钮

public class CircleTextView extends TextView {
    private Paint mPaint;

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

    public CircleTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public CircleTextView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init() {
        mPaint = new Paint();
        mPaint.setStyle(Paint.Style.FILL);
        mPaint.setColor(Color.RED);
        mPaint.setAntiAlias(true);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        int width = getWidth();
        int height = getHeight();
        int radius = Math.min(width, height) / 2;

        canvas.drawCircle(width / 2, height / 2, radius, mPaint);

        String text = getText().toString();
        mPaint.setColor(Color.WHITE);
        mPaint.setTextSize(30);
        mPaint.setTextAlign(Paint.Align.CENTER);
        canvas.drawText(text, width / 2, height / 2, mPaint);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int width = MeasureSpec.getSize(widthMeasureSpec);
        int height = MeasureSpec.getSize(heightMeasureSpec);
        int size = Math.min(width, height);
        setMeasuredDimension(size, size);
    }
}

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <View
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:background="#000000" />

    <com.example.CircleTextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Button"
        android:textColor="#FFFFFF"
        android:gravity="center"
        android:layout_gravity="center"
        android:padding="10dp" />

    <View
        android:layout_width="match_parent"
        android:layout_height="1dp"
        android:background="#000000" />

</LinearLayout>