在Android中制作一个三角形按钮

public class TriangleButton extends Button {
    private Path trianglePath;
    private Paint trianglePaint;

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

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

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

    private void init() {
        trianglePath = new Path();
        trianglePaint = new Paint();
        trianglePaint.setColor(Color.BLUE);
        trianglePaint.setStyle(Paint.Style.FILL);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        int width = getWidth();
        int height = getHeight();

        trianglePath.reset();
        trianglePath.moveTo(0, height);
        trianglePath.lineTo(width, height);
        trianglePath.lineTo(width / 2, 0);
        trianglePath.close();

        canvas.drawPath(trianglePath, trianglePaint);

        super.onDraw(canvas);
    }
}

<com.example.myapplication.TriangleButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Triangle Button" />