能够分页显示的Label控件

          话说分页这玩意在开发中可是相当的常见。网上到处都是分页的资料。可是在Winform中要做到分页显示文本内容就没有那么容易。而且不能使用一些可以分页的控件，比较DateGridView等。只好在已有的代码基础上开发了一个具备分页功能，并且可以改变行间距的Label。

代码写的比较长，可以拷贝下来直接使用，体验下。

using System;
using System.ComponentModel;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;
using System.Drawing;
using System.Text.RegularExpressions;

    public partial class LabelEx : System.Windows.Forms.Label
    {
        int lineDistance = 5;//行间距
        Graphics gcs;
        int iHeight = 0, height = 200;
        string[] nrLine;
        string[] nrLinePos;
        int searchPos = 0;
        int section = 1;
        int sectionHeight = 5;
        int pageHeight = 100;
        DispMode dm = DispMode.None;
        private int pageno = 1;
        private bool isend = false;//是否尾页
        public event EventHandler EndPage;
        ///Label所在的容器的高度
        private int containerHeight=0;
        ///Label在容器下端显示不了时附加高度
        private int attachHeight = 20;

        //是否清除文本中的Html文本标签
        private bool fClearHtml = false;

        [DescriptionAttribute("")]
        public bool FClearHtml
        {
            get { return fClearHtml; }
            set
            {
                fClearHtml = value;
            }
        }

        [DescriptionAttribute("Label在容器下端显示不了时附加高度")]
        public int AttachHeight
        {
            get { return attachHeight; }
            set
            {
                attachHeight = value;
            }
        }


        [DescriptionAttribute("Label所在的容器的高度")]
        public int ContainerHeight  
        {
            get { return containerHeight; }
            set
            {
                containerHeight = value;
            }
        }

        [DescriptionAttribute("获取或设置行距")]
        public int LineDistance
        {
            get { return lineDistance; }
            set
            {
                lineDistance = value;
                Changed(this.Font, this.Width, this.Text);
            }
        }
        [DescriptionAttribute("页码,在翻页模式下有用")]
        public int PageNo
        {
            get { return pageno; }
            set
            {
                if (value > 0 && pageno != value)
                {
                    if (isend && value>pageno)
                        return;
                    pageno = value;
                    this.Refresh();
                    
                }
            }
        }
        public LabelEx()
            : base()
        {
            //this.TextChanged += new EventHandler(LabelEx_TextChanged);
            this.SizeChanged += new EventHandler(LabelEx_SizeChanged);
            this.FontChanged += new EventHandler(LabelEx_FontChanged);
            //this.Font = new Font(this.Font.FontFamily, this.Font.Size, GraphicsUnit.Pixel);
        }

        void LabelEx_FontChanged(object sender, EventArgs e)
        {
            Changed(this.Font, this.Width, this.Text);
        }

        void LabelEx_SizeChanged(object sender, EventArgs e)
        {
            Changed(this.Font, this.Width, this.Text);
        }

        public LabelEx(IContainer container)
        {
            container.Add(this);
            //base.Height

            //InitializeComponent();
        }
        [DescriptionAttribute("页面高度,在翻页模式下有用")]
        public int PageHeight
        {
            get { return pageHeight; }
            set
            {
                pageHeight = value;
                base.Height = value;
            }
        }
        [DescriptionAttribute("呈现模式")]
        public DispMode DisplayMode
        {
            get { return dm; }
            set { dm = value; }
        }
        [DescriptionAttribute("获取文字高度")]
        public int FHeight
        {
            get { return this.Font.Height; }
        }
        [DescriptionAttribute("获取行高")]
        public int LineHeight
        {
            get { return this.Font.Height + lineDistance; }
        }
        public int SectionHeight
        {
            get { return this.Font.Height + sectionHeight; }
        }
        [DescriptionAttribute("设置或获取段落间距")]
        public int SecDisTance
        {
            get { return sectionHeight; }
            set { sectionHeight = value; }
        }
        public new int Height
        {
            get { return height; }
            set
            {
                height = value;
                base.Height = value;
            }
        }
        public override string Text
        {
            get
            {
                return base.Text;
            }
            set
            {
                //is.Font.Size.  
                if (FClearHtml)
                {
                    base.Text=value;
                    string strText = base.Text;
                    strText = ClearHtml(strText);
                    base.Text = strText;
                    Changed(this.Font, this.Width, strText);
                }
                else
                {
                    base.Text = value;
                    Changed(this.Font, this.Width, value);
                }
                
            }
        }

        public bool IsEnd
        {
            get { return isend; }
        }
        protected void Changed(Font ft, int iWidth, string value)
        {
            iHeight = 0;
            if (value != "")
            {
                if (gcs == null)
                {
                    gcs = this.CreateGraphics();
                    SizeF sf0 = gcs.MeasureString(new string('测', 20), ft);
                    searchPos = (int)(iWidth * 20 / sf0.Width);
                    if (searchPos > 2) searchPos -= 2;

                }

                nrLine = value.Split(new string[1] { "\r\n" }, StringSplitOptions.RemoveEmptyEntries);
                section = nrLine.Length;
                nrLinePos = new string[section];
                SizeF sf1, sf2;
                string temps, tempt;
                string drawstring;
                int temPos, ipos;
                for (int i = 0; i < section; i++)
                {
                    ipos = 0;
                    temPos = searchPos;
                    if (searchPos >= nrLine[i].Length)
                    {
                        ipos += nrLine[i].Length;
                        nrLinePos[i] += "," + ipos.ToString();
                        iHeight++;
                        continue;
                    }
                    drawstring = nrLine[i];
                    nrLinePos[i] = "";
                    while (drawstring.Length > searchPos)
                    {
                        bool isfind = false;
                        for (int j = searchPos; j < drawstring.Length; j++)
                        {
                            temps = drawstring.Substring(0, j);
                            tempt = drawstring.Substring(0, j + 1);
                            sf1 = gcs.MeasureString(temps, ft);
                            sf2 = gcs.MeasureString(tempt, ft);
                            if (sf1.Width < iWidth && sf2.Width > iWidth)
                            {
                                iHeight++;
                                ipos += j;
                                nrLinePos[i] += "," + ipos.ToString();
                                isfind = true;
                                drawstring = drawstring.Substring(j);
                                break;

                            }

                        }
                        if (!isfind)
                        {
                            //drawstring = drawstring.Substring(searchPos);
                            //iHeight++;
                            break;
                        }
                    }
                    ipos += drawstring.Length;
                    nrLinePos[i] += "," + ipos.ToString();
                    iHeight++;

                    //tempLine = (int)(sf1.Width - 1) / this.Width + 1;                        
                    //iHeight += tempLine;
                }
            }
            if (dm == DispMode.None)
            {
                //this.Height = iHeight * (ft.Height + lineDistance) + (section - 1) * (sectionHeight - lineDistance);

                //add by kevin gao 20110511 --------------begine
                if (value == "")
                {
                    this.Height = 0;
                    return;
                }
                if (this.ContainerHeight == 0)
                {
                    this.Height = iHeight * (ft.Height + lineDistance) + (section - 1) * (sectionHeight - lineDistance);
                }
                else
                {
                    int tmpHeight = 0;
                    int fHeight = ft.Height;
                    for (int i = 0; i < section; i++)
                    {
                        int iLineNum = 0;
                        if (nrLinePos[i] == null || nrLinePos[i] == "")
                        {
                            return;
                        }
                        string strLinePos = nrLinePos[i].TrimStart(',');
                        iLineNum = strLinePos.Split(',').Length;
                        for (int j = 0; j < iLineNum; j++)
                        {
                            int iTop = this.Top + tmpHeight;
                            if (ContainerHeight == 0)
                            {
                                return;
                            }
                            //if (this.Top < 0)
                            //{
                            //    iTop = ContainerHeight + this.Top + tmpHeight;
                            //}
                            int RelTop = iTop % ContainerHeight;
                            int TempHeight = 0;
                            if (j == iLineNum - 1)
                            {
                                TempHeight = RelTop + (fHeight + sectionHeight);
                            }
                            else
                            {
                                TempHeight = RelTop + (fHeight + lineDistance);
                            }
                            if (TempHeight > ContainerHeight)
                            {
                                if (RelTop + fHeight > containerHeight)
                                {
                                    AttachHeight = ContainerHeight - RelTop;
                                    tmpHeight += AttachHeight;
                                }
                                //tmpHeight += TempHeight - ContainerHeight + 2;
                            }
                            if (j == iLineNum - 1)
                            {
                                tmpHeight += fHeight + sectionHeight;
                            }
                            else
                            {
                                tmpHeight += fHeight + lineDistance;
                            }
                        }
                    }
                    this.Height = tmpHeight;
                }
                //add by kevin gao 20110511 --------------end
            }
        }
        protected override void OnPaint(System.Windows.Forms.PaintEventArgs e)
        {
            //base.OnPaint(e);           
            //if (isPaint) return;
            //isPaint = true;
            Graphics g = e.Graphics;
            String drawString = this.Text;
            Font drawFont = this.Font;
            SolidBrush drawBrush = new SolidBrush(this.ForeColor);
            SizeF textSize = g.MeasureString(this.Text, this.Font);//文本的矩形区域大小   
            int lineCount = Convert.ToInt16(textSize.Width / this.Width) + 1;//计算行数   
            int fHeight = this.Font.Height;
            int htHeight = 0;
            bool isPageStart = false;
            this.AutoSize = false;
            float x = 0.0F;
            StringFormat drawFormat = new StringFormat();
            lineCount = drawString.Length;//行数不超过总字符数目   
            int i, idx, first;
            string subStr, tmpStr = "", midStr = "";
            string[] idxs;
            int tmpPage = 1;
            isend = false;
            string preLineStr = "";
            for (i = 0; i < section; i++)
            {
                if (i == 10)
                {
                    first = 0;
                }
                first = 0;
                subStr = nrLine[i];
                if (nrLinePos[i] != null) tmpStr = nrLinePos[i].TrimStart(',');
                midStr = subStr.Substring(first);
                if (tmpStr != "")
                {

                    idxs = tmpStr.Split(',');
                    for (int j = 0; j < idxs.Length; j++)
                    {
                        idx = int.Parse(idxs[j]);                       
                        midStr = subStr.Substring(first, idx - first);
                        if (dm == DispMode.None)
                        {
                            //add by kevin gao 20110511 ---begine
                            if (ContainerHeight == 0)
                            {
                                e.Graphics.DrawString(midStr, drawFont, drawBrush, x, Convert.ToInt16(htHeight), drawFormat);
                            }
                            else
                            {
                                int iTop = this.Top + htHeight;
                                if (this.Top < 0)
                                {
                                    iTop = ContainerHeight + this.Top + htHeight;
                                }
                                int RelTop = iTop % ContainerHeight;
                                int TempHeight = 0;
                                if (j == idxs.Length - 1)
                                {
                                    TempHeight = RelTop + (fHeight + sectionHeight);
                                }
                                else
                                {
                                    TempHeight = RelTop + (fHeight + lineDistance);
                                }

                                if (TempHeight > ContainerHeight)
                                {
                                    if (RelTop + fHeight > containerHeight)
                                    {
                                        AttachHeight = ContainerHeight - RelTop;
                                        htHeight += AttachHeight;
                                        e.Graphics.DrawString(midStr, drawFont, drawBrush, x, Convert.ToInt16(htHeight), drawFormat);
                                    }
                                    else
                                    {
                                        e.Graphics.DrawString(midStr, drawFont, drawBrush, x, Convert.ToInt16(htHeight), drawFormat);
                                    }
                                }
                                else
                                {
                                    e.Graphics.DrawString(midStr, drawFont, drawBrush, x, Convert.ToInt16(htHeight), drawFormat);
                                }
                            }
                            //add by kevin gao 20110511 ---end
                            //e.Graphics.DrawString(midStr, drawFont, drawBrush, x, Convert.ToInt16(htHeight), drawFormat);
                        }
                        else
                        {
                            if ((htHeight + fHeight) > pageHeight)
                            {

                                tmpPage++;
                                if (tmpPage > pageno)
                                {
                                    //e.Graphics.DrawString(midStr, drawFont, drawBrush, x, Convert.ToInt16(htHeight), drawFormat);
                                    this.Height = htHeight + fHeight;
                                    if (i == section - 1 && j == idxs.Length - 1)
                                    {
                                        isend = true;
                                        if (EndPage != null)
                                            EndPage(this, e);
                                    }
                                    return;
                                }
                                preLineStr = midStr;
                                isPageStart = true;
                                htHeight = 0;
                            }
                            else
                            {
                                if (tmpPage == pageno)
                                {
                                    if (isPageStart)
                                    {
                                        e.Graphics.DrawString(preLineStr, drawFont, drawBrush, x, 0, drawFormat);
                                    }
                                    isPageStart = false;
                                    e.Graphics.DrawString(midStr, drawFont, drawBrush, x, Convert.ToInt16(htHeight), drawFormat);
                                }
                                if (i == section - 1 && j == idxs.Length - 1)
                                {
                                    isend = true;
                                    if (EndPage != null)
                                        EndPage(this, e);
                                }
                            }
                        }
                        if (j == idxs.Length - 1)
                        {
                            htHeight += (fHeight + sectionHeight);
                        }
                        else
                        {
                            htHeight += (fHeight + lineDistance);
                        }
                        first = idx;
                    }
                }
            }
        }

        /// <summary>
        /// 清除文本中的Html标签
        /// </summary>
        /// <param name="patrn">要替换的标签正则表达式</param>
        /// <param name="strRep">替换为的内容</param>
        /// <param name="content">要替换的内容</param>
        /// <returns></returns>
        private string Zxj_ReplaceHtml(string patrn, string strRep, string content)
        {
            if (string.IsNullOrEmpty(content))
            {
                content = "";
            }
            Regex rgEx = new Regex(patrn, RegexOptions.IgnoreCase);
            string strTxt = rgEx.Replace(content, strRep);
            return strTxt;
        }
        /// <summary>
        /// 清除文本中Html的标签
        /// </summary>
        /// <param name="Content"></param>
        /// <returns></returns>
        private string ClearHtml(string Content)
        {
            Content = Zxj_ReplaceHtml("&#[^>]*;", "", Content);
            Content = Zxj_ReplaceHtml("</?marquee[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?object[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?param[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?embed[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?table[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("&nbsp;", "", Content);
            Content = Zxj_ReplaceHtml("</?tr[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?th[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?p[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?a[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?img[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?tbody[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?li[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?span[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?div[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?th[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?td[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?script[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("(javascript|jscript|vbscript|vbs):", "", Content);
            Content = Zxj_ReplaceHtml("on(mouse|exit|error|click|key)", "", Content);
            Content = Zxj_ReplaceHtml("<\\?xml[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("<\\/?[a-z]+:[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?font[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?b[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?u[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?i[^>]*>", "", Content);
            Content = Zxj_ReplaceHtml("</?strong[^>]*>", "", Content);
            string clearHtml = Content;
            return clearHtml;
        }

    }
    /// <summary>
    /// 显示模式，分为全显示和分页显示两种
    /// </summary>
    public enum DispMode
    {
        None = 0,
        Page = 1
    }