1.2.10 #

internal class VisualCounter
{
    private readonly string _name;
    private int _count;
    private readonly int _max;
    private int _operatorTimes;

    /// <summary>
    /// 构造函数。
    /// </summary>
    /// <param name="id">计数器的名称。</param>
    /// <param name="max">计数器的最大值。</param>
    /// <param name="operatorTimes">计数器的最大操作数。</param>
    public VisualCounter(string id, int max, int operatorTimes)
    {
        _name = id;
        _max = max;
        _operatorTimes = operatorTimes;
    }

    /// <summary>
    /// 计数器加一。
    /// </summary>
    public bool Increment()
    {
        if (_operatorTimes <= 0)
            return false;
        if (_count < _max)
        {
            _count++;
            _operatorTimes--;
        }
        return true;
    }

    /// <summary>
    /// 计数器减一。
    /// </summary>
    public bool Decreasement()
    {
        if (_operatorTimes <= 0)
            return false;
        if (_count > 0)
        {
            _count--;
            _operatorTimes--;
        }
        return true;
    }

    /// <summary>
    /// 获取当前计数值。
    /// </summary>
    /// <returns>返回计数值。</returns>
    public int Tally()
    {
        return _count;
    }

    /// <summary>
    /// 返回形如 “1 counter” 的字符串。
    /// </summary>
    /// <returns>返回形如 “1 counter” 的字符串。</returns>
    public override string ToString()
    {
        return _count + " " + _name;
    }

    /// <summary>
    /// 绘制计数器的图形。
    /// </summary>
    /// <param name="g">画布。</param>
    /// <param name="width">绘图区宽度。</param>
    /// <param name="height">绘图区高度。</param>
    /// <param name="font">显示的字体。</param>
    public void Draw(Graphics g, int width, int height, Font font)
    {
        // 空画布
        g.Clear(SystemColors.Control);
        // 画布分为上 1/3 和下 2/3
        var headPart = new RectangleF(0, 0, width, height / 3);
        var bodyPart = new Rectangle(0, height / 3, (height * 2) / 3, (height * 2) / 3);

        // 绘图
        g.DrawString($"计数：{_count} 剩余操作数：{_operatorTimes} 最大值：{_max}", font, Brushes.Black, headPart);
        g.FillPie(Brushes.Blue, bodyPart, 0, 360 * (float)_count / _max);
    }
}

using System;
using System.Drawing;
using System.Windows.Forms;

namespace _1._2._10
{
    public partial class Form2 : Form
    {
        VisualCounter counter;
        Graphics graphics;
        public Form2(int N, int max)
        {
            InitializeComponent();
            counter = new VisualCounter("count", max, N);
            graphics = this.PaintArea.CreateGraphics();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (!counter.Increment())
            {
                this.ErrorLabel.Text = "操作数不足";
            }
            else
            {
                this.ErrorLabel.Text = "";
                counter.Draw(graphics,this.PaintArea.Width, this.PaintArea.Height, this.Font);
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (!counter.Decreasement())
            {
                this.ErrorLabel.Text = "操作数不足";
            }
            else
            {
                this.ErrorLabel.Text = "";
                counter.Draw(graphics, this.PaintArea.Width, this.PaintArea.Height, this.Font);
            }
        }
    }
}