ASP.NET购物车实现过程详解

时间:2022-02-18 13:34:00

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:

ASP.NET购物车实现过程详解

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。

ASP.NET购物车实现过程详解

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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;
      }
    }
  }

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:

ASP.NET购物车实现过程详解

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;

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();
    }
}

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>

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();
   
  }

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();
}

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();
 
  }
}

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。