?? 顯示數組(關聯關系).txt
字號:
關鍵：
在頁中包含頁指令System.Data
向DataSet中多加一個表并建立關聯
1.頁面
<%@ Page language="c#" Codebehind="MyKind.aspx.cs" AutoEventWireup="false" Inherits="Co_112.MyKind" %>
<%@ Import Namespace="System.Data" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
<title>MyKind</title>
<meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1">
<meta name="CODE_LANGUAGE" Content="C#">
<meta name="vs_defaultClientScript" content="JavaScript">
<meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
</HEAD>
<body MS_POSITIONING="GridLayout">
<form id="Form1" method="post" runat="server">
<asp:DataGrid id="DataGrid1" style="Z-INDEX: 101; LEFT: 224px; POSITION: absolute; TOP: 208px"
runat="server" AutoGenerateColumns="False">
<Columns>
<asp:BoundColumn DataField="employeeid" HeaderText="ID"></asp:BoundColumn>
<asp:BoundColumn DataField="firstname" HeaderText="First Name"></asp:BoundColumn>
<asp:TemplateColumn HeaderText="Reports">
<ItemTemplate>
<asp:CheckBox id=CheckBox1 runat="server" Enabled="False" Checked='<%# HasBoss((int)DataBinder.Eval(Container.DataItem,"boss")) %>'>
</asp:CheckBox>
</ItemTemplate>
</asp:TemplateColumn>
<asp:TemplateColumn HeaderText="Territories">
<ItemTemplate>
<asp:DropDownList id=DropDownList1 runat="server" Width="120px" DataSource="<%# GetTerritories((DataRowView)Container.DataItem) %>">
</asp:DropDownList>
</ItemTemplate>
</asp:TemplateColumn>
</Columns>
</asp:DataGrid>
</form>
</body>
</HTML>
2.代碼
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using System.Text;
namespace Co_112
{
/// <summary>
/// 顯示布爾值。
/// </summary>
public class MyKind : System.Web.UI.Page
{
protected System.Web.UI.WebControls.DataGrid DataGrid1;
private void Page_Load(object sender, System.EventArgs e)
{
if(!Page.IsPostBack)
{
Display();
}
}
private void Display()
{
string strConn,strCmd;
strConn="server=localhost;uid=sa;pwd=;database=Northwind";
//添加第一個表
// ISNULL:使用指定的替換值替換 NULL
strCmd="Select employeeid,titleofcourtesy,firstname,lastname,title,ISNULL(reportsto,0) AS boss From employees";
SqlDataAdapter oCMD=new SqlDataAdapter(strCmd,strConn);
DataSet oDS=new DataSet();
oCMD.Fill(oDS,"EmployeesTable");
//添加第二個表
string ss="Select et.employeeid,t.territorydescription From EmployeeTerritories As et Inner join Territories As t on t.territoryid=et.territoryid";
SqlDataAdapter da=new SqlDataAdapter(ss,strConn);
da.Fill(oDS,"TerritoriesTable");
DataColumn dc1=oDS.Tables["EmployeesTable"].Columns["employeeid"];
DataColumn dc2=oDS.Tables["TerritoriesTable"].Columns["employeeid"];
//建立關聯
DataRelation dre1=new DataRelation("EmployeesAndTerritories",dc1,dc2);
oDS.Relations.Add(dre1);
DataGrid1.DataSource=oDS.Tables["EmployeesTable"];
DataGrid1.DataBind();
oDS.Dispose();
oDS=null;
oCMD.Dispose();
oCMD=null;
}
public bool HasBoss(int bossID)
{
if(bossID!=0)
return true;
return false;
}
public ArrayList GetTerritories(DataRowView drv)
{
DataRow dr=drv.Row;//提取底層行
//根據關系檢索子行
DataRow [] adr=dr.GetChildRows("EmployeesAndTerritories");
//創建并返回一個數組列表
ArrayList a=new ArrayList();
foreach(DataRow tmp in adr)
a.Add(tmp["territorydescription"]);
return a;
}
#region Web 窗體設計器生成的代碼
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: 該調用是 ASP.NET Web 窗體設計器所必需的。
//
InitializeComponent();
base.OnInit(e);
}
/// <summary>
/// 設計器支持所需的方法 - 不要使用代碼編輯器修改
/// 此方法的內容。
/// </summary>
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load);
}
#endregion
}
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