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

namespace MyControls
{
    /// <summary>
    /// 在图上显示的标尺类
    /// </summary>
    public partial class Control_Ruler : UserControl
    {
        #region 变量定义
        private string m_showstring = "1mm";
        private double m_f_value = 1;  //实际表示的长度值
        //private float m_bs = 0;//倍数，计算使用

        /// <summary>
        /// 显示在标尺上的文字
        /// </summary>
        public string ShowString
        {
            get { return m_showstring; }
            set { m_showstring = value; }
        }

        /// <summary>
        /// 设置标尺的宽度也就是控件的宽度，里面实际参与计算的标尺宽度为,
        /// 左右边各减10的宽度，也就是整宽-20的宽度,这里传入实际宽度，不参与计算
        /// </summary>
        public int RulerWidth
        {
            get { return this.Width - 20; }
            set { this.Width = value + 20; }
        }

        /// <summary>
        /// 用来存储该标尺，实际的值是多少，用来与显示的宽度进行换算
        /// </summary>
        public double Value
        {
            get { return m_f_value; }
            set { this.m_f_value = value; }
        }
        #endregion

        #region 构造函数及窗体加载
        public Control_Ruler()
        {
            InitializeComponent();
        }

        private void Control_Ruler_Load(object sender, EventArgs e)
        {
            SetDoubleBufferByIsDraw();

            //设置Style支持透明背景色
            this.SetStyle(ControlStyles.SupportsTransparentBackColor, true);
            this.BackColor = Color.FromArgb(200, 255, 255, 255);
        }

        #endregion

        #region 设置双缓冲
        /// <summary>
        /// 设置双缓冲
        /// </summary>
        public void SetDoubleBufferByIsDraw()
        {
            SetStyle(ControlStyles.UserPaint, true);
            SetStyle(ControlStyles.AllPaintingInWmPaint, true); // 禁止擦除背景.
            this.SetStyle(ControlStyles.OptimizedDoubleBuffer, true); // 双缓冲
        }
        #endregion

        #region 绘制事件
        protected override void OnPaint(PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            Brush b = new SolidBrush(Color.Black);
            Pen p = new Pen(b);
            p.Width = 1;

            //直线
            g.DrawLine(p, 10, 20, this.Width - 10, 20);

            //两个竖线
            g.DrawLine(p, 10, 10, 10, 30);
            g.DrawLine(p, this.Width - 10, 10, Width - 10, 30);

            //写上要输出的文字
            g.DrawString(m_showstring, new Font("宋体", 9), b, this.Width / 2-10, 25);
        }
        #endregion

        /// <summary>
        /// 设置当前标尺长度
        /// </summary>
        public void SetValue(int in_value)
        {
            this.Width = in_value + 20; //有20的宽度是边，所以补上
        }
        /// <summary>
        /// 
        /// </summary>
        /// <param name="in_value"></param>
        /// <param name="showstring"></param>
        public void SetValue(int in_value,string showstring)
        {
            this.Width = in_value + 20; //有20的宽度是边，所以补上
            m_showstring = showstring + "mm";
        }
    }
}