目录
关于数据感应
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
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：
范例运行环境
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
设计
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：
实现
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：
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
调用示例
数据源
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：
调用
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;
}
小结
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。