在Java中的文本框上绘制对角线

public void paint(Graphics g) {
    Graphics2D g2d = (Graphics2D) g;
    g2d.setStroke(new BasicStroke(2));
    g2d.setColor(Color.BLACK);
    
    int width = getWidth();
    int height = getHeight();
    
    // 计算对角线起点和终点坐标
    int x1 = 0;
    int y1 = height / 2;
    int x2 = width - 1;
    int y2 = height / 2;
    
    // 计算对角线的斜率
    double slope = (y2 - y1) / (x2 - x1);
    
    // 计算对角线长度
    int length = (int) Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2));
    
    // 计算对角线起点的坐标
    int x3 = x1 + length * (y1 - y2) / slope;
    int y3 = y2 - length * (x2 - x3) / slope;
    
    // 绘制对角线
    g2d.drawLine(x1, y1, x3, y3);
    
    // 清除笔画样式并绘制文本
    g2d.dispose();
    g.drawString("Hello, World!", 10, 20);
}