DataSet用法一：添加代码创建的表DataTable，设置主键外键，读取及修改DataSet表中数据

原文发布时间为：2008-08-01 —— 来源于本人的百度文章 [由搬家工具导入]

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;

public partial class dataset : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            DataSet ds = new DataSet();
            DataTable dt1 = new DataTable("user");
            DataTable dt2 = new DataTable("book");
           

            dt1.Columns.Add("uid", typeof(Int32));
            dt1.Columns.Add("uname", typeof(string));

            dt2.Columns.Add("bid", typeof(Int32));
            dt2.Columns.Add("bname", typeof(string));
           
            ds.Tables.Add(dt1);
            ds.Tables.Add(dt2);
           
            object[] userdata = new object[2];
            object[] bookdata = new object[2];

            userdata[0] = 1;
            userdata[1] = "wjwu";
          
            bookdata[0] = 1;
            bookdata[1] = "English";

            Session["ds"]=ds;

            dt1.Rows.Add(userdata);
            dt2.Rows.Add(bookdata);

            fill();
        }
        
    }
    private void fill()
    {
        DataSet ds = new DataSet();
        ds = (DataSet)Session["ds"];
        GridView1.DataSource = ds.Tables["user"];
        GridView1.DataBind();

        GridView2.DataSource = ds.Tables["book"];
        GridView2.DataBind();
    }

  
    protected void addrow_Click(object sender, EventArgs e)
    {
       //增加表数据
        DataSet ds = new DataSet();
        ds = (DataSet)Session["ds"];

        object[] add = new object[2];
        add[0] = 2;
        add[1] = "lucy";

        try
        {
            ds.Tables["user"].Rows.Add(add);
            Session["ds"] = ds;
            fill();
        }
        catch (Exception ex)
        {
            Response.Write("<script>alert('" + ex.Message + "')</script>");
        }       
    }
   
    protected void pk_Click(object sender, EventArgs e)
    {
        //设置主键
        DataSet ds = new DataSet();
        ds = (DataSet)Session["ds"];

        UniqueConstraint uc = new UniqueConstraint("userpk", ds.Tables["user"].Columns["uid"],true);
        ds.Tables["user"].Constraints.Add(uc);
       
        Session["ds"] = ds;
        fill();
    }

    protected void fk_Click(object sender, EventArgs e)
    {//设置外键
       
        DataSet ds = new DataSet();
        ds = (DataSet)Session["ds"];
        ForeignKeyConstraint fkc = new ForeignKeyConstraint("userfk", ds.Tables["user"].Columns["uid"], ds.Tables["book"].Columns["bid"]);
        ds.Tables["book"].Constraints.Add(fkc);
        Session["ds"] = ds;
        fill();
    }

    protected void Button1_Click(object sender, EventArgs e)
    {
        DataSet ds = new DataSet();
        ds = (DataSet)Session["ds"];

        Label1.Text = ds.Tables["user"].Rows[0]["uname"].ToString();
    }

    protected void Button2_Click(object sender, EventArgs e)
    {
        DataSet ds = new DataSet();
        ds = (DataSet)Session["ds"];
        ds.Tables["book"].Rows[0]["bname"] = TextBox1.Text;
        Session["ds"] = ds;
        fill();
    }
}