1、 将test数据库附加到数据库管理系统中;数据库中的book_info包含下列数据:
2、 新建一个网站,将images文件夹复制到网站中;
3、 在Default.aspx中,通过DataList控件展示数据库中的所有数据,以行为主序,每行3列,单击购买按钮时,将商品的ID和数量保存到HashTable中,并将HashTable放置到Session中。
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protected void DataList1_ItemCommand( object source, DataListCommandEventArgs e)
{
string id = e.CommandArgument.ToString();
Hashtable ht;
if (Session[ "shopcar" ] == null )
{
ht = new Hashtable();
ht.Add(id, 1);
Session[ "shopcar" ] = ht;
}
else
{
ht = (Hashtable)Session[ "shopcar" ];
if (ht.Contains(id))
{
int count = int .Parse(ht[id].ToString());
ht[id] = count + 1;
Session[ "shopcar" ] = ht;
Response.Write(count + 1);
}
else
{
ht.Add(id, 1);
Session[ "shopcar" ] = ht;
}
}
}
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4、 在Default.aspx中添加一个超链接,链接到shopcart.aspx,在shopcart.aspx中显示用户购买的商品信息。
提示:
A、在shopcart中先定义下列变量:
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Hashtable ht;
DataTable dt;
string connstring= @"DataSource=.\SQLEXPRESS;Initial Catalog=test;Integrated Security=True" ;
SqlConnection conn;
SqlCommand cmd;
SqlDataReader sdr;
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B、页面中添加一个GridView。
C、在page_load中,将dt实例化,建立各列。
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protected void Page_Load(object sender, EventArgs e)
{
dt = new DataTable();
DataColumn col = new DataColumn();
col.ColumnName= "id";
col.DataType =System.Type.GetType("System.String");
dt.Columns.Add(col);
col = new DataColumn();
col.ColumnName= "name";
col.DataType =System.Type.GetType("System.String");
dt.Columns.Add(col);
col = new DataColumn();
col.ColumnName= "Num";
col.DataType =System.Type.GetType("System.Int32");
dt.Columns.Add(col);
col = new DataColumn();
col.ColumnName= "price";
col.DataType =System.Type.GetType("System.Single");
dt.Columns.Add(col);
col = new DataColumn();
col.ColumnName= "Total";
col.DataType =System.Type.GetType("System.Single");
dt.Columns.Add(col);
if (!IsPostBack)
{
Bind();
}
}
public void Bind()
{
if (Session["shopcar"] == null)
{
Response.Write("< script >if(confirm('你没有登录')window.location='Default15.aspx';else window.close();</ script >");
}
else
{
ht = (Hashtable)Session["shopcar"];
foreach (object item in ht.Keys)
{
string id = item.ToString();
int num = int.Parse(ht[item].ToString());
string sql = "selectbook_name,price from book_info where book_id='" + id + "'";
conn = new SqlConnection(connstring);
cmd = new SqlCommand(sql, conn);
conn.Open();
sdr =cmd.ExecuteReader();
if (sdr.HasRows)
{
sdr.Read();
DataRow row = dt.NewRow();
row["id"] = id;
row["Num"] = num;
row["name"] = sdr.GetString(0);
row["price"] =float.Parse(sdr[1].ToString());
row["total"] =num*(float.Parse(sdr[1].ToString()));
dt.Rows.Add(row);
}
sdr.Close();
conn.Close();
}
GridView1.DataSource = dt.DefaultView;
GridView1.DataBind();
}
}
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D、这时可以看到用户购买的商品,但不能修改数量,也不能删除。
E、添加修改数量,删除商品功能,在aspx页面中定义GridView中的各列:
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<asp:GridView ID= "GridView1" runat= "server" AutoGenerateColumns= "False" >
<Columns>
<asp:BoundField DataField= "id" HeaderText= "ID" />
<asp:BoundField DataField= "name" HeaderText= "名称" />
<asp:BoundField DataField= "price" HeaderText= "价格" />
<asp:TemplateField>
<ItemTemplate>
<asp:TextBox runat= "server" ID= "textbox1" Text= '<%# Eval("Num") %>'
ontextchanged= "textbox1_TextChanged" AutoPostBack= "True" ></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField= "total" HeaderText= "总计" />
<asp:TemplateField>
<ItemTemplate>
<asp:Button runat= "server" ID= "button1" CommandArgument= '<%# Eval("id") %>'
Text= "删除" onclick= "button1_Click" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
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F、为GridView中的文本框添加TextChanged事件:
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protected void textbox1_TextChanged( object sender, EventArgs e)
{
Hashtable ht =(Hashtable)Session[ "shopcar" ];
if (ht == null ) return ;
for ( int i = 0; i < GridView1.Rows.Count;i++)
{
string id =GridView1.Rows[i].Cells[0].Text.ToString();
Response.Write(id);
string num = ((TextBox)GridView1.Rows[i].FindControl( "textbox1" )).Text;
Response.Write( " " +num+ "<br />" );
ht[id] = num;
}
Session[ "shopcar" ] = ht;
Bind();
}
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G、为按钮添加单击事件:
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protected void button1_Click( object sender, EventArgs e)
{
string id = ((Button)sender).CommandArgument;
Hashtable ht = (Hashtable)Session[ "shopcar" ];
if (ht == null ) return ;
ht.Remove(id);
Bind();
}
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购物车代码:showcart.aspx.cs
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using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Collections;
using System.Data;
using System.Data.SqlClient;
public partial class shopcart : System.Web.UI.Page
{
Hashtable ht;
DataTable dt;
string connstr = "Data Source=.\\SQLEXPRESS;AttachDbFilename=F:
\\test.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True";
SqlConnection conn;
SqlCommand cmd;
SqlDataReader sdr;
protected void Page_Load( object sender, EventArgs e)
{
dt = new DataTable();
DataColumn col = new DataColumn();
col.ColumnName = "id" ;
col.DataType = System.Type.GetType( "System.String" );
dt.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "name" ;
col.DataType = System.Type.GetType( "System.String" );
dt.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "Num" ;
col.DataType = System.Type.GetType( "System.Int32" );
dt.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "price" ;
col.DataType = System.Type.GetType( "System.Single" );
dt.Columns.Add(col);
col = new DataColumn();
col.ColumnName = "Total" ;
col.DataType = System.Type.GetType( "System.Single" );
dt.Columns.Add(col);
if (!IsPostBack)
{
Bind();
}
}
public void Bind()
{
if (Session[ "shopcar" ] == null )
{
Response.Write( "<script>if(confirm('你没有登录')window.location='Default.aspx';else window.close();</script>" );
}
else
{
ht = (Hashtable)Session[ "shopcar" ];
foreach ( object item in ht.Keys)
{
string id = item.ToString();
int num = int .Parse((ht[item].ToString()));
string sql = "select book_name,price from book_info where book_id='" + id + "'" ;
conn = new SqlConnection(connstr);
cmd = new SqlCommand(sql, conn);
conn.Open();
sdr = cmd.ExecuteReader();
if (sdr.HasRows)
{
sdr.Read();
DataRow row = dt.NewRow();
row[ "id" ] = id;
row[ "Num" ] = num;
row[ "name" ] = sdr.GetString(0);
row[ "price" ] = float .Parse(sdr[1].ToString());
row[ "total" ] = num * ( float .Parse(sdr[1].ToString()));
dt.Rows.Add(row);
}
sdr.Close();
conn.Close();
}
}
GridView1.DataSource = dt.DefaultView;
GridView1.DataBind();
}
protected void textbox1_TextChanged( object sender, EventArgs e)
{
Hashtable ht = (Hashtable)Session[ "shopcar" ];
if (ht == null ) return ;
for ( int i = 0; i < GridView1.Rows.Count; i++)
{
string id = GridView1.Rows[i].Cells[0].Text.ToString();
Response.Write(id);
string num = ((TextBox)GridView1.Rows[i].FindControl( "textbox1" )).Text;
Response.Write( " " + num + "<br />" );
ht[id] = num;
}
Session[ "shopcar" ] = ht;
Bind();
}
protected void button1_Click( object sender, EventArgs e)
{
string id = ((Button)sender).CommandArgument;
Hashtable ht = (Hashtable)Session[ "shopcar" ];
if (ht == null ) return ;
ht.Remove(id);
Bind();
}
}
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制作一个简单的购物车就是这么简单,大家可以按照我的思路进行创作,在此基础上在添加一些功能。