自己开发的自定义分页控件

　　一直以来都觉得分页是麻烦的事情，.NET中虽然有DATAGRID的分页，但用其他形式的列表仍然需要使用到分页，一次一次的写不利于效率及面向对象的方法，用类或用户控件也总觉得怪怪的，用第3方的自己觉得不放心，也不利于自己进行修改，干脆就自己写了一个。

　　(另外注意：在控件编译时，可以在AssemblyInfo.cs文件中设置控件的标签和名称空间，如：
       using System.Reflection;
       using System.Runtime.CompilerServices;
       using System.Web.UI; 
       [assembly: TagPrefix("PublicControls","PublicControls")]  // 自定义控件前缀
　　第一个参数是名称空间（必须是你的控件类的名称空间），第二个是标签名（可自定义）

　　记得要加入System.Web.UI;名称空间，另外 将控件类内的    [DefaultProperty("Text"), 
     ToolboxData("<PublicControls:PageNavigation runat=server></PublicControls:PageNavigation>")]这句屏蔽掉

所有代码如下：

using System;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.ComponentModel;
using System.Collections;
using System.Collections.Specialized;



namespace PublicControls
{
     ///<summary>
     /// PageNavigation 分页导航控件。
     ///</summary>
     [DefaultProperty("Text"), 
     ToolboxData("<PublicControls:PageNavigation runat=server></PublicControls:PageNavigation>")]
     public class PageNavigation : Control,IPostBackDataHandler,IPostBackEventHandler 
     {
         #region预定义
         
         private string _style;
         private int _count;
         private int _pagesize;
         private int _pageindex;
        private int _pages;         //页群
         private int _currentpages;
         private string _first;
         private string _pres;
         private string _pre;
         private string _next;
         private string _nexts;
         private string _last;


         ///<summary>
         ///委托页面索引事件
         ///</summary>
         public event EventHandler PageIndexChange;

         #endregion

         #region属性
         
         ///<summary>
         ///相关属性样式字符串属性
         ///</summary>
         [Bindable(false), 
         Category("StyleString"), 
         DefaultValue("Align=left")] 
         public string StyleString 
         {
              get
              {
                   _style = (string)ViewState["StyleString"];
                   return _style;
              }

              set
              {
                   _style= value;
                   ViewState["StyleString"] = _style;
              }
         }

         ///<summary>
         ///记录总数
         ///</summary>
         [Bindable(false), 
         Category("Count"), 
         DefaultValue(0)] 
         public int Count 
         {
              get
              {
                   if (this.IsNumeric(ViewState["Count"]))
                   {
                       _count = (int)ViewState["Count"];
                   }
                   return _count;
              }

              set
              {
                   _count = value;
                   ViewState["Count"] = _count;
                   
              }
         }

         ///<summary>
         ///页面大小
         ///</summary>
         [Bindable(false), 
         Category("Pagesize"), 
         DefaultValue(10)] 
         public int Pagesize
         {
              get
              {
                   
                   if (this.IsNumeric(ViewState["Pagesize"]))
                   {
                       _pagesize = (int)ViewState["Pagesize"];
                   }
                   return _pagesize;
              }

              set
              {
                   _pagesize = value;
                   ViewState["Pagesize"] = _pagesize;
                   
              }
         }

         ///<summary>
         ///当前页索引
         ///</summary>
         [Bindable(false), 
         Category("Pageindex"), 
         DefaultValue(0)] 
         public int Pageindex
         {
              get
              {
                   if (this.IsNumeric(ViewState["Pageindex"]))
                   {
                       _pageindex = (int)ViewState["Pageindex"];
                   }
                   return _pageindex;
              }

              set
              {
                   _pageindex = value;
                   ViewState["Pageindex"] = _pageindex;
              }
         }

         ///<summary>
         ///页群属性
         ///</summary>
         public int Pages
         {
              get
              {
                   if (this.IsNumeric(ViewState["Pages"]))
                   {
                       _pages = (int)ViewState["Pages"];
                   }
                   return _pages;
              }
              set
              {
                   _pages = value;
                   ViewState["Pages"] = _pages;
              }
         }

         ///<summary>
         ///当前页群索引
         ///</summary>
         public int CurrentPages
         {
              get
              {
                   if (this.IsNumeric(ViewState["CurrentPages"]))
                   {
                       _currentpages = (int)ViewState["CurrentPages"];
                   }
                   return _currentpages;
              }
              set
              {
                   _currentpages = value;
                   ViewState["CurrentPages"] = _currentpages;
              }
         }

         ///<summary>
         ///标记样式
         ///</summary>
         [Bindable(false), 
         Category("first"), 
         DefaultValue("第一页")] 
         public string First 
         {
              get
              {
                   _first = (string)ViewState["First"];
                   return _first;
              }

              set
              {
                   _first = value;
                   ViewState["First"] = _first;
              }
         }

         ///<summary>
         ///标记样式
         ///</summary>
         [Bindable(false), 
         Category("pres"), 
         DefaultValue("前N页")] 
         public string Pres 
         {
              get
              {
                   _pres = (string)ViewState["Pres"];
                   return _pres;
              }

              set
              {
                   _pres = value;
                   ViewState["Pres"] = _pres;
              }
         }

         ///<summary>
         ///标记样式
         ///</summary>
         [Bindable(false), 
         Category("pre"), 
         DefaultValue("前一页")] 
         public string Pre 
         {
              get
              {
                   _pre = (string)ViewState["Pre"];
                   return _pre;
              }

              set
              {
                   _pre = value;
                   ViewState["Pre"] = _pre;
              }
         }

         ///<summary>
         ///标记样式
         ///</summary>
         [Bindable(false), 
         Category("next"), 
         DefaultValue("后一页")] 
         public string Next 
         {
              get
              {
                   _next = (string)ViewState["Next"];
                   return _next;
              }

              set
              {
                   _next = value;
                   ViewState["Next"] = _next;
              }
         }

         ///<summary>
         ///标记样式
         ///</summary>
         [Bindable(false), 
         Category("nexts"), 
         DefaultValue("后N页")] 
         public string Nexts 
         {
              get
              {
                   _nexts = (string)ViewState["Nexts"];
                   return _nexts;
              }

              set
              {
                   _nexts = value;
                   ViewState["Nexts"] = _nexts;
              }
         }

         ///<summary>
         ///标记样式
         ///</summary>
         [Bindable(false), 
         Category("last"), 
         DefaultValue("最后一页")] 
         public string Last 
         {
              get
              {
                   _last = (string)ViewState["Last"];
                   return _last;
              }
              set
              {
                   _last = value;
                   ViewState["Last"] = _last;
              }
         }


         #endregion

         #region事件
         ///<summary>
         ///当由类实现时，使服务器控件能够处理将窗体发送到服务器时引发的事件。
         ///</summary>
         ///<param name="e">所传递的参数</param>
         public void RaisePostBackEvent(string e) 
         {
              //当发生回送的时候改变控件当前索引
              if(e=="top")
              {
                   Pageindex = 0;
                   CurrentPages = 0 ;
              }
              else if(e=="last")
              {
                   Pageindex = (Count+Pagesize-1)/Pagesize -1;
                   
                   CurrentPages = ((Count+Pagesize-1)/Pagesize+Pages-1)/ Pages -1;

                   if(Pageindex<0)
                   {
                       Pageindex=0;
                   }
                   if(CurrentPages<0)
                   {
                       CurrentPages=0;
                   }
                   
              }
              else if(e=="pre")
              {
                   if(Pageindex>0)
                   {
                       Pageindex--;
                       if(Pageindex<CurrentPages*Pages && Pageindex>0)
                       {
                            CurrentPages--;
                       }
                   }
              }
              else if(e=="next")
              {
                   if(Pageindex<(Count+Pagesize-1)/Pagesize -1)
                   {
                       Pageindex++;
                       if(Pageindex>(CurrentPages+1)*Pages-1 && Pageindex<Count-1)
                       {
                            CurrentPages++;
                       }
                   }
              }
              else if(e=="pres")
              {
                   Pageindex -= Pages;
                   if(Pageindex<0)
                   {
                       Pageindex = 0;
                   }
                   if(Pageindex<CurrentPages*Pages && Pageindex>0)
                   {
                       CurrentPages--;
                   }
              }
              else if(e=="nexts")
              {
                   Pageindex += Pages;
                   if(Pageindex>(Count+Pagesize-1)/Pagesize -1)
                   {
                       Pageindex = (Count+Pagesize-1)/Pagesize -1;
                   }
                   if(Pageindex>(CurrentPages+1)*Pages-1 && Pageindex<Count-1)
                   {
                       CurrentPages++;
                   }
              }
              else
              {
                   Pageindex = int.Parse(e.ToString());
              }
         
              //发生回送事件时引发OnPageIndexChange事件
              OnPageIndexChange(System.EventArgs.Empty);
         }

         ///<summary>
         ///当由类实现时，为 ASP.NET 服务器控件处理回发数据。
         ///</summary>
         ///<param name="postDataKey">数据集合元素索引</param>
         ///<param name="values">string 的排序集合</param>
         ///<returns></returns>
         public bool LoadPostData(string postDataKey, NameValueCollection values) 
         {
              //Pageindex = Int32.Parse(values[this.UniqueID].Split('|')[0]);
              //CurrentPages = Int32.Parse(values[this.UniqueID].Split('|')[1]);
              return false;
         }

         ///<summary>
         ///当由类实现时，用信号要求服务器控件对象通知 ASP.NET 应用程序该控件的状态已更改。
         ///</summary>
         public void RaisePostDataChangedEvent() 
         {
         }

         ///<summary>
         ///当页面索引改变，触发委托
         ///</summary>
         ///<param name="e"></param>
         protected void OnPageIndexChange(System.EventArgs e)
         {    
              //委托给加载控件页的PageIndexChange事件
              if (PageIndexChange!=null)
              {
                   PageIndexChange(this,e);
              }
         }

         ///<summary>
         ///预呈现
         ///</summary>
         ///<param name="e"></param>
         protected override void OnPreRender(EventArgs e) 
         {
         }

         #endregion

         #region输出
         ///<summary>
         ///将此控件呈现给指定的输出参数。
         ///</summary>
         ///<param name="output">要写出到的 HTML 编写器 </param>
         protected override void Render(HtmlTextWriter output)
         {

              string Pagestring = "";  //定义页码呈现字符串
              string Text = null;          //输出主结构字符串变量定义
              int NO;

              //输出主结构
              Text = "<div $style$>";
              
              Text +="<a href =/"javascript:"+ Page.GetPostBackEventReference(this,"top")+ "/">"+First+"</a> ";

              Text +="<a href =/"javascript:"+ Page.GetPostBackEventReference(this,"pres")+ "/">"+Pres+"</a> ";

              Text +="<a href =/"javascript:"+ Page.GetPostBackEventReference(this,"pre")+ "/">"+Pre+"</a> ";

              Text +="$Pagestring$";

              Text +="<a href =/"javascript:"+ Page.GetPostBackEventReference(this,"next")+ "/">"+Next+"</a> ";

              Text +="<a href =/"javascript:"+ Page.GetPostBackEventReference(this,"nexts")+ "/">"+Nexts+"</a> ";
              
              Text +="<a href =/"javascript:"+ Page.GetPostBackEventReference(this,"last")+ "/">"+Last+"</a> ";

              Text +="</div>";//<input type = hidden name ="+this.UniqueID+" value = "+this.Pageindex+"|"+this.CurrentPages+">";     

              //当页大小小于0时，还原为1，防止预算出现除0错误
              if (!(Pagesize>0))
              {
                   Pagesize = 1;
              }
              
              

              //计算出总页数，并循环输出页码
              for (int i = 0;i< Pages ;i++ )
              {
                   //获得页群内页码
                   NO = Pages * CurrentPages + i;

                   if(NO<(Count+Pagesize-1)/Pagesize)
                   {
                       //判断页码是否为当前页
                       if (Pageindex != NO)
                       {
                            Pagestring += "<a href = /"javascript:"+ Page.GetPostBackEventReference(this,NO.ToString())+ "/">"+(NO+1).ToString()+"</a> ";
                       }
                            //如果不是，页面部分无连接
                       else
                       {
                            Pagestring += (NO+1).ToString()+" ";
                       }
                   }
              }

              if (!(Pagestring.Trim().Length>0))
              {
                   Pagestring = "1";
              }
              
              //替换对齐属性
              Text = Text.Replace("$style$",StyleString);
            
              //替换页码部分
              Text = Text.Replace("$Pagestring$",Pagestring);
              

              output.Write(Text);
              
         }
         #endregion

         #region其他函数
         ///<summary>
         ///判断是否为数字字符串
         ///</summary>
         ///<param name="str">需验证的字符串</param>
         ///<returns>判断结果，符合条件为True,不符合条件为False</returns>
         public bool IsNumeric(string str)
         {
              //判断是否为空
              if (str == null || str.Length==0) 
              {
                   return false; 
              }
              //循环检查每个字符
              foreach(char c in str) 
              { 
                   if (!Char.IsNumber(c)) 
                   { 
                       return false; 
                   } 
              } 
              return true; 
         }

         ///<summary>
         ///判断是否为数字字符串
         ///</summary>
         ///<param name="obj">需验证的字符串</param>
         ///<returns>判断结果，符合条件为True,不符合条件为False</returns>
         public bool IsNumeric(object obj)
         {

              obj += "";
              string str = obj.ToString();
              
              //判断是否为空
              if (str == null || str.Length==0) 
              {
                   return false; 
              }
              //循环检查每个字符
              foreach(char c in str) 
              { 
                   if (!Char.IsNumber(c)) 
                   { 
                       return false; 
                   } 
              } 
              return true; 
         }

         #endregion
     }
}