Asp.net Study(13)
DataList控件
包含的模板：ItemTemplate,HeaderTemplate,FooterTemplate,AlternatingItemTemplate,SeparatorTemplate,SelectedItemTemplate,EditItemTemplate
同时DataList控件提供了Repeater不具备的RepeatDriection and RepeatColumns属性
RepeatDirection可以取两个值：Horizontal and Vertical(默认为Vertical)
学习内容：SelectedItemTemplate,EditItemTemplate
注意：在OnItemCommand的响应函数中score.SelectedIndex=e.Item.ItemIndex这句如果没有的话，也可以正常运行，只是在最后的结果中要点击连接两次才会显示SelectedItemTemplate中的内容。
代码：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="DataGridSort.aspx.cs" Inherits="DataGridSort" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.OleDb" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<script runat=server>
OleDbConnection Myconn;
public void Page_Load(Object src, EventArgs e)
{
//连接语句
string Myconnstring = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath(".") + "..\\data\\score.mdb;";
Myconn = new OleDbConnection(Myconnstring);
Myconn.Open();
if (!IsPostBack)
{
BindGrid();
}
}
//创建默认视图
ICollection Createtable()
{
string strsel = "select * from score";
OleDbDataAdapter MyAdapter = new OleDbDataAdapter(strsel, Myconn);
DataSet ds=new DataSet();
MyAdapter.Fill(ds, "score");
return ds.Tables["score"].DefaultView;
}
//数据绑定
public void BindGrid()
{
score.DataSource = Createtable();
score.DataBind();
}
//select命令响应函数
public void DataList_ItemCommand(Object sender, DataListCommandEventArgs e)
{
score.SelectedIndex = e.Item.ItemIndex;
BindGrid();
}
//编辑命令响应函数
public void DataList_EditCommand(Object sender, DataListCommandEventArgs e)
{
score.EditItemIndex = e.Item.ItemIndex;
BindGrid();
}
//取消命令响应函数
public void DataList_CancelCommand(Object sender, DataListCommandEventArgs e)
{
score.EditItemIndex = -1;
BindGrid();
}
//更新命令响应函数
public void DataList_UpdateCommand(Object sender, DataListCommandEventArgs e)
{
string strname=((Label)e.Item.FindControl("lblname")).Text;
int intmath=Int32.Parse(((TextBox)e.Item.FindControl("tbmath")).Text);
int intenglish=Int32.Parse(((TextBox)e.Item.FindControl("tbenglish")).Text);
int intchinese=Int32.Parse(((TextBox)e.Item.FindControl("tbchinese")).Text);
string strupdate = "Update score set s_Math=" +intmath+ ",s_English=" +intenglish+ ",s_Chinese=" +intchinese+ " where s_Name=’" +strname+ "’";
OleDbCommand Mycommand = new OleDbCommand(strupdate, Myconn);
Mycommand.ExecuteNonQuery();
score.EditItemIndex = -1;
BindGrid();
}
</script>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:DataList ID="score"
HeaderStyle-BackColor=ActiveCaptionText
AlternatingItemStyle-BackColor=ActiveCaption
runat=server
OnItemCommand="DataList_ItemCommand"
OnEditCommand="DataList_EditCommand"
OnCancelCommand="DataList_CancelCommand"
OnUpdateCommand="DataList_UpdateCommand"
SelectedItemStyle-BackColor=red
RepeatLayout=Table>
<ItemTemplate>
Name:<%# DataBinder.Eval(Container.DataItem,"s_Name") %>
<asp:LinkButton Text="Details" id="btnselect" CommandName="select" runat=server/>
<asp:LinkButton Text="Edit" ID="btnedit" CommandName="edit" runat=server/>
</ItemTemplate>
<SelectedItemTemplate>
Name:<%# DataBinder.Eval(Container.DataItem,"s_Name") %><br>
Math:<%# DataBinder.Eval(Container.DataItem,"s_Math") %><br>
English:<%# DataBinder.Eval(Container.DataItem,"s_English") %><br>
Chinese:<%# DataBinder.Eval(Container.DataItem,"s_Chinese") %><br>
</SelectedItemTemplate>
<EditItemTemplate>
Name:<asp:Label ID="lblname" Text='<%# DataBinder.Eval(Container.DataItem,"s_Name") %>’ runat=server/><br>
Math:<asp:TextBox ID="tbmath" Text='<%# DataBinder.Eval(Container.DataItem,"s_Math") %>’ runat=server/><br>
English:<asp:TextBox ID="tbenglish" Text='<%# DataBinder.Eval(Container.DataItem,"s_English") %>’ runat=server/><br>
Chinese:<asp:TextBox ID="tbchinese" Text='<%# DataBinder.Eval(Container.DataItem,"s_Chinese") %>’ runat=server/><br>
<asp:LinkButton ID="lblupdate" Text="Update" CommandName="Update" runat=server/>
<asp:LinkButton ID="lblcancel" Text="Cancel" CommandName="Cancel" runat=server/>
</EditItemTemplate>
</asp:DataList>
</div>
</form>
</body>
</html>
DataList的分页功能
现在的水平，程序只能照教材抄，自己来理一下程序的思路。
注：在程序调试的过程中，在return ds.Tables["score"].DefaultView处出现了一个错误，提示“需要输入符号”，当时没能解决，关了电脑，除去吃了个饭，回来再打开，调试，ok了。
1，分页所需要的数据：PageSize,PageCount,RecordCount,PageIndex,CurrentPage(给ViewState["PageIndex"]付值用)
2，编写函数去得到相应数据
3，首先通过StartIndex取得需要显示的页的第一条记录的Index值 StartIndex=CurrentPage*PageSize
然后通过MyAdapter.Fill()方法获得要显示的页的默认视图MyAdapter.Fill(ds,StartIndex,PageSize,"score")
4， 绑定数据。对是否是首页或是末页进行判断（通过CurrentPage<PageCount-1 and CurrentPage>0进行判断），如果是首页则设置lbnPrevPage.Enabled=false，如果是末页则设置 lbnNextPage.Enabled=false
5，使用swith case函数对要进行上翻页还是下翻页进行判断，上翻和下翻的命令用e.CommandName来取得
6，最后设置ViewState["PageIndex"]=CurrentPage
代码：
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="DataListPageIndex.aspx.cs" Inherits="DataListPageIndex" %>
<%@ Import Namespace="System.Data"%>
<%@ Import Namespace="System.Data.OleDb"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<script runat=server>
OleDbConnection Myconn;
int PageSize, ItemCount, RecordCount, PageCount, CurrentPage;
public void Page_Load(Object src, EventArgs e)
{
PageSize = 2;
//连接语句
string Myconnstring="Provider=Microsoft.Jet.OLEDB.4.0;Data Source="+Server.MapPath(".")+"..\\data\\score.mdb;";
Myconn=new OleDbConnection(Myconnstring);
Myconn.Open();
//第一次请求执行
if (!IsPostBack)
{
ListBind();
CurrentPage = 0;
ViewState["PageIndex"] = 0;
//计算记录条数
RecordCount = CalculateRecord();
lblRecordCount.Text = RecordCount.ToString();
//计算总共有多少页
PageCount = RecordCount / PageSize;
lblPageCount.Text = PageCount.ToString();
ViewState["PageCount"] = PageCount;
}
}
//计算记录条数
public int CalculateRecord()
{
int intCount;
string strCount = "select Count(*) as co from score";
OleDbCommand Mycommand = new OleDbCommand(strCount, Myconn);
OleDbDataReader dr = Mycommand.ExecuteReader();
if (dr.Read())
{
intCount = Int32.Parse(dr["co"].ToString());
}
else
{
intCount = 0;
}
dr.Close();
return intCount;
}
//创建数据源
ICollection DataSource()
{
//设定读取的起始位置
int startindex;
startindex = CurrentPage*PageSize;
string strsel="select * from score";
OleDbDataAdapter MyAdapter=new OleDbDataAdapter(strsel,Myconn);
DataSet ds=new DataSet();
MyAdapter.Fill(ds,startindex,PageSize,"score");
return ds.Tables["score"].DefaultView;
}
//数据绑定
public void ListBind()
{
score.DataSource = DataSource();
score.DataBind();
lbnNextPage.Enabled = true;
lbnPrevPage.Enabled = true;
if (CurrentPage == PageCount – 1) lbnNextPage.Enabled = false;
if (CurrentPage == 0) lbnPrevPage.Enabled = false;
lbnCurrentPage.Text = (CurrentPage + 1).ToString();
}
//Page_OnClick事件处理
public void Page_OnClick(Object sender,CommandEventArgs e)
{
PageCount = (int)ViewState["PageCount"];
CurrentPage = (int)ViewState["PageIndex"];
//判断翻页方向
string cmd=e.CommandName;
switch(cmd)
{
case "Next":
if(CurrentPage<(PageCount-1)) CurrentPage++;
break;
case "Prev":
if(CurrentPage>0) CurrentPage–;
break;
}
ViewState["PageIndex"]=CurrentPage;
ListBind();
}
</script>
<title>DataListPageIndex</title>
</head>
<body>
<form id="form1" runat="server">
<div>
Total<asp:Label ID="lblRecordCount" runat=server/>record Current<asp:Label ID="lbnCurrentPage" ForeColor=Red runat=server/>/<asp:Label ID="lblPageCount" ForeColor=red runat=server/>page
<asp:DataList ID="score" AlternatingItemStyle-BackColor=ControlDarkDark HeaderStyle-BackColor=AntiqueWhite runat=server>
<ItemTemplate>
Name:<%# DataBinder.Eval(Container.DataItem,"s_Name")%>
</ItemTemplate>
</asp:DataList>
<asp:LinkButton ID="lbnPrevPage" OnCommand="Page_OnClick" CommandName="Prev" runat=server Text="PrevPage"/>
<asp:LinkButton ID="lbnNextPage" OnCommand="Page_OnClick" CommandName="Next" runat=server Text="NextPage"/>
</div>
</form>
</body>
</html>
