赞
踩
目录
数据感应也即数据捆绑,是一种动态的,Web控件与数据源之间的交互,本文将继续介绍以与数据库提取数据并捆绑控件为例,讲解 C# 创建适用于 BaseDataList 类(如DataGrid)的通用分页数据显示方法。
BaseDataList 类是包括如 DataList 、DataGrid 服务器控件的基类,本文我们以 DataGrid 服务器控件控件,并结合 MS SQL SERVER 和 达梦数据库,以数据分页的形式,绑定 DataGrid进行显示。
更多 BaseDataList 类的介绍请参照如下链接:
操作系统: Windows Server 2019 DataCenter
.net版本: .netFramework4.7.1 或以上
开发工具:VS2019 C#
数据提取:在这里我们以能够支持 MS SQL Server 2016、国产达梦数据 8 的通用数据库内容提取方法为例, 生成数据源需要利用 ADO.NET 中的数据提供者对象包括IDbConnection、IDbCommand、IDbDataParameter等,如何使用这些对象请参考我的文章:
《C#实现 IDbConnection / IDbCommand 等相关通用数据接口》
pageview 方法内置了分页函数写法(目前支持 MS SQL Server 2016 和国产达梦 8 数据库 ),另外传递SQL关键命令及配置相关参数,将数据源分页感应到指定的 BaseDataList 类控件上,其参数说明如下表:
序号 | 参数名 | 类型 | 说明 |
---|---|---|---|
1 | DbServerType | string | 目前支持 "oracle"、 "dm8",其它字符串均视为 MS SQL Server |
2 | strConn | string | 对应数据库的连接字符串 |
3 | webctls | string[] | 对应的信息标签和选择框的ID集合,如果不指定则按默认值处理,即: webctls[0]="q_pageno"; //当前页 |
4 | navsender | string | 导航按钮的 CommandArgument, nav1 表示首页,nav2 表示上一页,nav3表示下一页,nav4表示最后一页 |
5 | dbgrid | System.Web.UI.WebControls. BaseDataList | 用于捆绑 BaseDataList 的控件,如DataGrid |
6 | DisplayFieldList | string | 用于捆绑到 BaseDataList 的控件上的字段列表,以逗号进行分隔 |
7 | SelectedFieldList | string | SQL 查询语句的 select 部分,即查询字段列表,DisplayFieldList 参数是它的子集 |
8 | OrderFieldList | string | SQL 查询语句的 order by 部分,字段以逗号进行分隔 |
9 | FromTableList | string | SQL 查询语句的 from 部分,表名以逗号进行分隔 |
10 | WhereStatements | string | SQL 查询语句的 where 条件部分, 字符串需要书写 where 字样 |
11 | paras | ArrayList | 查询条件中的参数对象集合 |
12 | keyfield | string | 查询结果集的唯一标识字段,用于统计总数 |
13 | OuterFromTableList | string | 是否有用于左、右连接的表名列表 |
14 | OuterWhereStatements | string | 用于左、右连接的查询条件 |
15 | movWhereToOuter | bool | 是否用左、右连接查询条件替代where查询条件(如果需要) |
16 | GroupFuncs | ArrayList | 一组需要特殊指定的统计变量值,其添加string[]对象,string[0] 存储字段名,string[1]存储变量名 |
pageview 方法完整代码如下:
- public string pageview(string DbServerType,string strConn,string[] webctls,string navsender,System.Web.UI.WebControls.BaseDataList dbgrid,string DisplayFieldList,string SelectedFieldList,string OrderFieldList,string FromTableList,string WhereStatements,ArrayList paras,string keyfield,string OuterFromTableList,string OuterWhereStatements,bool movWhereToOuter,ArrayList GroupFuncs)
- {
-
- string[] defaultobj=new string[5];
- defaultobj[0]="q_pageno"; //当前页
- defaultobj[1]="q_pagecount"; //页总数
- defaultobj[2]="q_recordcount"; //总记录数
- defaultobj[3]="q_pagesize"; //可选择的每页记录数
- defaultobj[4]="q_pageno_label"; //可选择的每页记录数
-
- if(webctls==null)
- {
- webctls=defaultobj;
- }
- if(webctls.GetLength(0)<4){
- webctls=defaultobj;
- }
- ObjectEx oe=new ObjectEx();
- oe.RunAt=RunAt;
- oe.FindContainer=FindContainer;
- int _npc=0;
- int _now=1;
- try
- {
- _now=int.Parse(oe.GetBaseClassText(webctls[0]));
- if(oe.GetBaseClassText(webctls[1])!="")
- {
- _npc=int.Parse(oe.GetBaseClassText(webctls[1]));
- }
- }
- catch(Exception)
- {
- _now=1;
- _npc=1;
- oe.SetBaseClassText(webctls[0],"1");
- oe.SetBaseClassText(webctls[1],"1");
- }
- string navtype=oe.GetBaseClassArg(navsender);
- if(navtype=="nav1")
- {
- _now=1;
- }
- if(navtype=="nav2")
- {
- _now--;
- }
- if(navtype=="nav3")
- {
- _now++;
- }
- if(navtype=="nav4")
- {
- _now=_npc;
- }
- if(navtype=="nav5")
- {
- _now=int.Parse(oe.GetBaseClassText(webctls[0]));
- }
- if(_now>_npc)
- {
- _now=_npc;
- }
- if(_now<1)
- {
- _now=1;
- }
- _now--;
-
- IDbConnection Conn = GetConnection(DbServerType, strConn);
- IDataReader myDr;
- string _countf=keyfield;
- string _pagesize=oe.GetBaseClassList(webctls[3],"Value");
- _pagesize=(_pagesize==""?"50":_pagesize);
-
- if(movWhereToOuter==true)
- {
- WhereStatements=WhereStatements.Replace("where 1=1","");
- if(OuterWhereStatements.IndexOf("{0}")==-1)
- {
- OuterWhereStatements+=" "+WhereStatements;
- }
- else
- {
- OuterWhereStatements=string.Format(OuterWhereStatements,WhereStatements);
- }
- WhereStatements="";
- }
- string groupf="",resultf="",declare="",intolist= "RecordCount";
- if(GroupFuncs!=null)
- {
- for(int i=0;i<GroupFuncs.Count;i++)
- {
- string[] rv=(string[])GroupFuncs[i];
- if (DbServerType.ToLower() == "dm8")
- {
- intolist += "," + rv[1] ;
- groupf += "," + rv[0];
- resultf += "," + rv[1] + " " + rv[1];
- declare += " " + rv[1] + " " + rv[2] + " ";
- }
- else
- {
- groupf += ",@" + rv[1] + "=" + rv[0];
- resultf += ",@" + rv[1] + " " + rv[1];
- declare += " declare @" + rv[1] + " " + rv[2] + " ";
- }
- }
- }
- string CommandText = "DECLARE @PageIndex INT "+
- " DECLARE @PageSize INT "+
- " DECLARE @RecordCount INT "+
- " DECLARE @PageCount INT "+declare+
- "SET @PageIndex="+_now.ToString()+" "+
- "SET @PageSize="+_pagesize+" "+
- "SELECT @RecordCount =COUNT("+_countf+")"+groupf+" FROM "+FromTableList+" "+WhereStatements+" "+
- "SET @PageCount = CEILING(@RecordCount * 1.0 / @PageSize) "+
- " select @recordcount rc,@pagecount pc"+resultf+
- " SELECT "+DisplayFieldList+" FROM "+
- "(SELECT "+SelectedFieldList+","+
- "ROW_NUMBER() OVER (ORDER BY "+OrderFieldList+") AS sn "+
- "FROM "+FromTableList+" "+WhereStatements+") AS T "+OuterFromTableList+
- " WHERE T.sn > (@PageIndex * @PageSize) and T.sn <= ((@PageIndex+1) * @PageSize) "+OuterWhereStatements;
- if (DbServerType.ToLower() == "dm8")
- {
- CommandText = "declare PageIndex INT; " +
- " PageSize INT; " +
- " RecordCount INT; " +
- " PageCount INT; " + declare +
- "begin SET PageIndex=" + _now.ToString() + "; " +
- "SET PageSize=" + _pagesize + "; " +
- "SELECT COUNT(" + _countf + ") " + groupf +" into "+intolist+ " FROM " + FromTableList + " " + WhereStatements + " ;" +
- "SET PageCount = CEILING(RecordCount * 1.0 / PageSize) ;" +
- " select recordcount rc,pagecount pc" + resultf +";"+
- " SELECT " + DisplayFieldList + " FROM " +
- "(SELECT " + SelectedFieldList + "," +
- "ROW_NUMBER() OVER (ORDER BY " + OrderFieldList + ") AS sn " +
- "FROM " + FromTableList + " " + WhereStatements + ") AS T " + OuterFromTableList +
- " WHERE T.sn > (PageIndex * PageSize) and T.sn <= ((PageIndex+1) * PageSize) " + OuterWhereStatements+" ;"+
- " end;";
-
- }
- string _info="";
- try
- {
- ArrayList _paras = new ArrayList();
- if(paras!=null)
- {
- for(int i=0;i<paras.Count;i++)
- {
- if (DbServerType.ToLower() == "dm8") {
- _paras.Add(paras[i] as DmParameter);
- }
- else
- {
- _paras.Add((SqlParameter)paras[i]);
- }
- }
- }
- IDbCommand Cmd = GetCommand(DbServerType, CommandText, _paras, Conn);
-
- Conn.Open();
- if (DbServerType.ToLower() == "dm8")
- {
- myDr = Cmd.ExecuteReader() as DmDataReader;
- }
- else
- {
- myDr = Cmd.ExecuteReader() as SqlDataReader;
- }
- if (myDr.Read())
- {
- int pc=int.Parse(myDr["pc"].ToString());
- int rc=int.Parse(myDr["rc"].ToString());
- oe.SetBaseClassText(webctls[1],pc.ToString());
- oe.SetBaseClassText(webctls[2],rc.ToString());
- oe.SetBaseClassText(webctls[0],(_now+1).ToString());
- if(webctls.Length>4)
- {
- oe.SetBaseClassText(webctls[4],(_now+1).ToString());
- }
- if(GroupFuncs!=null)
- {
- for(int i=0;i<GroupFuncs.Count;i++)
- {
- string[] rv=(string[])GroupFuncs[i];
- oe.SetBaseClassText(rv[3],myDr[rv[1]].ToString());
- }
- }
- }
-
- if(myDr.NextResult())
- {
- dbgrid.DataSource=myDr;
- dbgrid.DataBind();
- }
- myDr.Close();
- }
- catch (Exception ex)
- {
- _info=ex.Message;
-
- }
-
- finally
- {
- Conn.Close();
- Conn.Dispose();
- }
- return _info;
- }//pageview
-

pageview方法中涉及对控件ID在Page页面的查找 ,及对基类的一些属性如Text进行设置,因此设计了一个 ObjectEx 类,实现一些控件的查找和设置方法,该类设计如下:
序号 | 成员 | 类型 | 说明 |
---|---|---|---|
1 | public System.Web.UI.HtmlControls.HtmlForm RunAt=null; | 属性 | 运行的Form平台,Asp.net中一般只设置一个Form |
2 | public System.Web.UI.Control FindContainer=null; | 属性 | 要查找的容器,一般设置为Page |
3 | public string GetBaseClassArg(string webctl) | 方法 | 得到指定ID控件的 CommandArgument |
4 | public string GetBaseClassList(string webctl,string gettype) | 方法 | 得到指定 ID 的 ListControl 控件的Text或Value值,gettype 参数值可以设置 Text 或 Value |
5 | public string GetBaseClassText(string webctl) | 方法 | 得到指定ID控件的 Text 属性 |
6 | public void SetBaseClassText(string webctl,string values) | 方法 | 设置指定ID控件的 Text 属性 |
类代码如下:
- public class ObjectEx
- {
- public System.Web.UI.HtmlControls.HtmlForm RunAt=null;
- public System.Web.UI.Control FindContainer=null;
-
-
- public string GetBaseClassArg(string webctl)
- {
-
- System.Web.UI.Control btnctl;
- btnctl=RunAt.FindControl(webctl);
- if(FindContainer!=null)
- {
- btnctl=FindContainer.FindControl(webctl);
- }
- if(btnctl==null)
- {
- return "";
- }
- if(btnctl.GetType()==typeof(System.Web.UI.HtmlControls.HtmlInputButton))
- {
- if(((System.Web.UI.HtmlControls.HtmlInputButton)btnctl).Attributes["CommandArgument"]!=null)
- return ((System.Web.UI.HtmlControls.HtmlInputButton)btnctl).Attributes["CommandArgument"].ToString();
- }
- if(btnctl.GetType()==typeof(System.Web.UI.WebControls.Button))
- {
- return ((System.Web.UI.WebControls.Button)btnctl).CommandArgument;
- }
- if(btnctl.GetType()==typeof(System.Web.UI.WebControls.ImageButton))
- {
- return ((System.Web.UI.WebControls.ImageButton)btnctl).CommandArgument;
- }
- if(btnctl.GetType()==typeof(System.Web.UI.WebControls.LinkButton))
- {
- return ((System.Web.UI.WebControls.LinkButton)btnctl).CommandArgument;
- }
- return "";
-
- }
- public string GetBaseClassText(string webctl)
- {
- System.Web.UI.Control btnctl;
- btnctl=RunAt.FindControl(webctl);
- if(FindContainer!=null)
- {
- btnctl=FindContainer.FindControl(webctl);
- }
- if(btnctl==null)
- {
- return "";
- }
- if(btnctl.GetType()==typeof(System.Web.UI.WebControls.TextBox))
- {
- return ((System.Web.UI.WebControls.TextBox)btnctl).Text;
- }
- if(btnctl.GetType()==typeof(System.Web.UI.WebControls.Label))
- {
- return ((System.Web.UI.WebControls.Label)btnctl).Text;
- }
- if(btnctl.GetType()==typeof(System.Web.UI.WebControls.Button))
- {
- return ((System.Web.UI.WebControls.Button)btnctl).Text;
- }
- if(btnctl.GetType()==typeof(System.Web.UI.WebControls.LinkButton))
- {
- return ((System.Web.UI.WebControls.LinkButton)btnctl).Text;
- }
- if(btnctl.GetType()==typeof(System.Web.UI.WebControls.HyperLink))
- {
- return ((System.Web.UI.WebControls.HyperLink)btnctl).Text;
- }
- return "";
- }
- public void SetBaseClassText(string webctl,string values)
- {
- System.Web.UI.Control btnctl;
- btnctl=RunAt.FindControl(webctl);
- if(FindContainer!=null)
- {
- btnctl=FindContainer.FindControl(webctl);
- }
- if(btnctl==null)
- {
- return;
- }
- if(btnctl.GetType()==typeof(System.Web.UI.WebControls.TextBox))
- {
- ((System.Web.UI.WebControls.TextBox)btnctl).Text=values;
- }
- if(btnctl.GetType()==typeof(System.Web.UI.WebControls.Label))
- {
- ((System.Web.UI.WebControls.Label)btnctl).Text=values;
- }
- if(btnctl.GetType()==typeof(System.Web.UI.WebControls.Button))
- {
- ((System.Web.UI.WebControls.Button)btnctl).Text=values;
- }
- if(btnctl.GetType()==typeof(System.Web.UI.WebControls.LinkButton))
- {
- ((System.Web.UI.WebControls.LinkButton)btnctl).Text=values;
- }
- if(btnctl.GetType()==typeof(System.Web.UI.WebControls.HyperLink))
- {
- ((System.Web.UI.WebControls.HyperLink)btnctl).Text=values;
- }
- }
- public string GetBaseClassList(string webctl,string gettype)
- {
- System.Web.UI.Control btnctl;
- btnctl=RunAt.FindControl(webctl);
- if(FindContainer!=null)
- {
- btnctl=FindContainer.FindControl(webctl);
- }
- if(btnctl==null)
- {
- return "";
- }
- return (gettype.ToLower()=="text"?((System.Web.UI.WebControls.ListControl)btnctl).SelectedItem.Text:((System.Web.UI.WebControls.ListControl)btnctl).SelectedItem.Value);
- }
-
-
- }//ObjectEx Class

我们以 MS SQL SERVER 为例,提取信息发布系统列表信息,如下图数据显示:
表(wp_infos)设计基本情况如下表:
序号 | 字段名 | 类型 | 说明 |
---|---|---|---|
1 | title | nvarchar(200) | 信息标题 |
2 | pub_time | datetime | 发布时间 |
在页面放置一个ID为 dbgrid 的 DataGrid 控件和一系列的导航按钮等控件,前端示例代码如下:
- <div align="center" id="panel">
- <table border="0" cellpadding="0" cellspacing="0" width="100%" style="border:1px solid #CFE2FF; border-top:2px solid #1A5FC9; background-color:#F7F9FF;" id="table310">
- <tr>
- <td align="center"><asp:DataGrid ID=dbgrid ShowHeader="True"
- ShowFooter="False" CellPadding="0" Border="0" forecolor="black" Runat=server EnableViewState=True /> </td>
- </tr>
- <tr>
- <td align="right"><table border="0" width="100%" cellspacing="0" cellpadding="0" id="table314" bgcolor="#EEF4FF">
- <tr>
- <td align="right" valign="middle" style="display:none;">
- <asp:ImageButton ID=ntop CommandArgument=nav1 OnClick=navpage ImageUrl="images/nav1.jpg" Visible="false" Runat=server/>
- <asp:ImageButton ID=nbtm CommandArgument=nav4 OnClick=navpage ImageUrl="images/nav4.jpg" Visible="false" Runat=server/><asp:dropdownlist id="x_pagesize" runat="server" style="font-size:9pt;font-family:宋体" Visible="false">
- <asp:ListItem Text="10" Value="10" />
- <asp:ListItem Text="20" Value="20" selected="true"/>
- <asp:ListItem Text="30" Value="30" />
- <asp:ListItem Text="40" Value="40" />
- <asp:ListItem Text="50" Value="50" />
- <asp:ListItem Text="100" Value="100" />
- </asp:dropdownlist><asp:ImageButton Text="go" id="gotopage" Visible="false" OnClick=navpage CommandArgument=nav5 ImageUrl="images/nav5.jpg" Runat=server/></td><td width="515" height="30"></td><td valign="middle" width="100" align="right">共计<asp:Label ID=nrc Runat=server/>条记录</td><td valign="middle" width="4"><img src="../images/2012/inner/inner_dg_l.jpg"></td><td valign="middle" width="46" align="center"><asp:Label ID=ngo Text="1" Runat=server/>/<asp:Label ID=npc Runat=server/></td><td valign="middle" align="left" width="135"><asp:ImageButton ID=nprv CommandArgument=nav2 OnClick=navpage ImageUrl="../images/2012/inner/inner_dg_btn_p.jpg" Runat=server/> <asp:ImageButton ID=nnxt CommandArgument=nav3 OnClick=navpage ImageUrl="../images/2012/inner/inner_dg_btn_n.jpg" Runat=server/></td>
- </tr>
- </table>
- </td>
- </tr>
- </table>
- </div>

后端调用示例代码如下:
- void navpage(Object sender,EventArgs e)
- {
-
- string _sql=" title,pub_time";
- string _wherecon="";
- String arg ="";
- try{
- arg=((ImageButton)sender).CommandArgument;
- }catch(Exception xe){
- arg=((LinkButton)sender).CommandArgument;
- }
- string DisplayFieldList="sn 序号,title 标题名称,pub_time 发布时间";
- string SelectedFieldList=_sql;
- string OrderFieldList="pub_time desc";
- string FromTableList="wp_infos";
- string WhereStatements="";
- object[] rv=GetWhere();
- WhereStatements=rv[0].ToString();
- string[] webctls=new string[4];
- webctls[0]="ngo";
- webctls[1]="npc";
- webctls[2]="nrc";
- webctls[3]="x_pagesize";
-
- pageview("sqlserver","您的数据连接串",webctls,((Control)sender).ID,dbgrid,DisplayFieldList,SelectedFieldList,OrderFieldList,FromTableList,WhereStatements,(ArrayList)rv[1],"id");
- }
- object[] GetWhere(){
- object[] rv=new object[2];
- string WhereStatements=" where 1=1 ";
-
- ArrayList paras = new ArrayList();
- if(q_title.Text!=""){
- SqlParameter para2=new SqlParameter("@title",SqlDbType.NVarChar,200);
- para2.Value=q_title.Text;
- paras.Add(para2);
- WhereStatements+=" and title like @title ";
- }
- if(q_pub_time1.Text!=""){
- SqlParameter para4=new SqlParameter("@pub_time1",SqlDbType.DateTime);
- para4.Value=q_pub_time1.Text;
- paras.Add(para4);
- WhereStatements+=" and pub_time>=@pub_time1 ";
- }
- if(q_pub_time2.Text!=""){
- SqlParameter para5=new SqlParameter("@pub_time2",SqlDbType.DateTime);
- para5.Value=q_pub_time2.Text;
- paras.Add(para5);
- WhereStatements+=" and pub_time<=@pub_time2 ";
- }
- rv[0]=WhereStatements;
- rv[1]=paras;
- return rv;
-
- }

本方法同时适用于达梦8数据库的数据分页技术,我们可以根据自己的实际需要扩充兼容的数据库功能,范例中所需数据库驱动链接库,请下载我的资源:
https://download.csdn.net/download/michaelline/89235824
感谢您的阅读,希望本文能够对您有所帮助。
Copyright © 2003-2013 www.wpsshop.cn 版权所有,并保留所有权利。