📄 显示数组(关联关系).txt
字号:
关键：
在页中包含页指令System.Data
向DataSet中多加一个表并建立关联
1.页面
<%@ 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.代码
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>
/// 显示布尔值。
/// </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";
//添加第一个表
// ISNULL:使用指定的替换值替换 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");
//添加第二个表
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"];
//建立关联
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;//提取底层行
//根据关系检索子行
DataRow [] adr=dr.GetChildRows("EmployeesAndTerritories");
//创建并返回一个数组列表
ArrayList a=new ArrayList();
foreach(DataRow tmp in adr)
a.Add(tmp["territorydescription"]);
return a;
}
#region Web 窗体设计器生成的代码
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
//
InitializeComponent();
base.OnInit(e);
}
/// <summary>
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load);
}
#endregion
}
}⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -