C# nder、事件参数（e） { SqlConnection=newsqlconnection（“数据源=192.168.0.65；初始目录=TestDataBase；持久安全信息=True；用户ID=sa；密码=mushko”）； 使用（连接） { //connection.Open（）； SqlCommand insert=new SqlCommand（“插入OOPR（CardCode、CardName、OpprId、CprCode、MaxSumLoc）值（@TextBox1、@TextBox2、@TextBox3、@TextBox4、@TextBox5）”，连接）；/（“+TextBox1.Text+”、“+TextBox2.Text+”、“+DropDownList1.Text+”、“+TextBox4.Text+”），连接）； insert.Parameters.AddWithValue（“@TextBox1”，TextBox1.Text）； insert.Parameters.AddWithValue（“@TextBox2”，TextBox2.Text）； insert.Parameters.AddWithValue（“@TextBox3”，TextBox3.Text）； insert.Parameters.AddWithValue（“@TextBox4”，TextBox4.Text）； insert.Parameters.AddWithValue（“@TextBox5”，TextBox4.Text）； connection.Open（）； //connection.CommandType=CommandType.Text； //connection.commandType=commandType.Text； //试一试 // { insert.ExecuteNonQuery（）； connection.Close（）； // } //抓住 //{ //TextBox5.Text=“在数据库上保存时出错”； //connection.Close（）； //} //TextBox1.Text=“”； //TextBox2.Text=“”； //TextBox3.Text=“”； //TextBox4.Text=“”； } } 受保护的无效按钮2\u单击（对象发送者，事件参数e） { this.ClientScript.RegisterClientScriptBlock（this.GetType（），“Close”，“window.Close（）”，true）； //这个。关闭（）； } 受保护的void DropDownList2\u SelectedIndexChanged（对象发送方，事件参数e） { } } }

这是apsx代码

<%@ Page Title="Home Page" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true"
    CodeBehind="Default.aspx.cs" Inherits="StackOver._Default" %>

<asp:Content ID="HeaderContent" runat="server" ContentPlaceHolderID="HeadContent">
</asp:Content>

<asp:Content ID="BodyContent" runat="server" ContentPlaceHolderID="MainContent">
    <h2>
        Welcome to ASP.NET!

        <asp:DropDownList ID="DropDownList1" runat="server" AutoPostBack="True" 
        onselectedindexchanged="DropDownList1_SelectedIndexChanged">
    </asp:DropDownList>

        <asp:DropDownList ID="DropDownList2" runat="server" 
            onselectedindexchanged="DropDownList2_SelectedIndexChanged">
        </asp:DropDownList>

    </h2>

           <br />
    <p>
    Business Partner Code :&nbsp; 
        <asp:TextBox ID="TextBox1" runat="server" Width="192px" ></asp:TextBox>
    </p>
    <p>
    Business Partner Name :
        <asp:TextBox ID="TextBox2" runat="server" Width="192px" ></asp:TextBox>
    </p>
    <p>
     Opportunity No. :&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
        <asp:TextBox ID="TextBox3" runat="server" Width="196px" ></asp:TextBox>
    </p>

    <p>
    Contact Person Name :&nbsp; 
        <asp:TextBox ID="TextBox4" runat="server" Width="196px" ></asp:TextBox>
    </p>

     <p>
      Total Amount Invoiced:&nbsp; 
        <asp:TextBox ID="TextBox5" runat="server" Width="193px" ></asp:TextBox>
    </p>
     <p>
    Business partner Territory:&nbsp; 
        <asp:TextBox ID="TextBox6" runat="server" Width="174px" ></asp:TextBox>
    </p>
     <p>
      Sales Employee:&nbsp; 
        <asp:TextBox ID="TextBox7" runat="server" Width="235px" ></asp:TextBox>

    </p>
    <p>
        &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;

         <asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Add" 
            Width="140px" />
        &nbsp;&nbsp; &nbsp;
        <asp:Button ID="Button2" runat="server" Text="Cancel" Width="149px" 
            onclick="Button2_Click" />

    </p>


</asp:Content>

欢迎使用ASP.NET！



业务伙伴代码：


业务伙伴名称：


机会编号：


联系人姓名：


发票总金额：


业务伙伴地区：


销售人员：

将筛选后的客户放入数据表（dt）中，并按如下方式填写：

DropDownList2.DataTextField = "CustomerName";
DropDownList2.DataValueField = "CustomerID";
DropDownList2.DataSource = dt;
DropDownList2.DataBind();

---

一旦list1触发selectedindexchanged事件，list2将更改其值

        protected void LoadOptions()
        {
            DataTable CardCode = new DataTable();
            string id, name, newName, name2;
            SqlConnection connection = new SqlConnection("Data Source=adfsadf;Initial Catalog=TestDatabse;Persist Security Info=True;User ID=asd;Password=asdf");
            using (connection)
            {
                SqlDataAdapter adapter = new SqlDataAdapter("SELECT T1.CardCode , T1.CardName, T2.OpprId,T1.CntctPrsn, T2.CprCode,T2.MaxSumLoc  FROM OCRD T1 left  join OOPR T2 on T1.CardCode=T2.CardCode" , connection);
                adapter.Fill(CardCode);
                if (CardCode.Rows.Count > 0)
                {
                    for (int i = 0; i < CardCode.Rows.Count; i++)
                    {

                        id = CardCode.Rows[i]["CardCode"].ToString();
                        name = CardCode.Rows[i]["CardName"].ToString();
                        newName = id + " ---- " + name;
                        //name2 = id;
                        DropDownList1.Items.Add(new ListItem(newName, id));

                        //*******HERE*****//
                        DropDownList2.DataSource = CardCode;
                        DropDownList2.DataBind();
                        DropDownList2.DataValueField = "CardCode";
                        DropDownList2.DataTextField = "CntctPrsn";

                        //*******HERE*****//
                    }
                }
            }
        }

        protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
        {


            string selected = DropDownList1.SelectedItem.Value;
            SqlConnection connection = new SqlConnection("Data Source=mydtasrc;Initial Catalog=TestDatabs;Persist Security Info=True;User ID=asf;Password=asdfgh");
            using (connection)
            {
                // SqlCommand theCommand = new SqlCommand("SELECT CardCode, CardName, OpprId, CprCode,MaxSumLoc  FROM OOPR WHERE CardCode = @CardCode", connection);

                SqlCommand theCommand = new SqlCommand("SELECT T1.CardCode , T1.CardName, T2.OpprId, T1.CntctPrsn,T2.CprCode  FROM OCRD T1 left  join OOPR T2 on T1.CardCode=T2.CardCode  where T1.CardCode=@CardCode", connection);


                connection.Open();
                theCommand.Parameters.AddWithValue("@CardCode", selected);
                theCommand.CommandType = CommandType.Text;

                SqlDataReader theReader = theCommand.ExecuteReader();

                if (theReader.Read())
                {
                    this.TextBox1.Text = theReader["CardCode"].ToString();
                    this.TextBox2.Text = theReader["CardName"].ToString();
                    this.TextBox5.Text = theReader["CprCode"].ToString();
                    this.TextBox3.Text = theReader["OpprId"].ToString();


                    //*******AND HERE*****//
                    this.DropDownList2.SelectedValue = selected; 

                    //*******AND HERE*****//
                }
                connection.Close();
            }

        }

protectedvoid LoadOptions（）
{
DataTable CardCode=新DataTable（）；
字符串id、名称、新名称、名称2；
SqlConnection=newsqlconnection（“数据源=adfsadf；初始目录=testdatabase；持久安全信息=True；用户ID=asd；密码=asdf”）；
使用（连接）
{
SqlDataAdapter=新的SqlDataAdapter（“选择T1.CardCode、T1.CardName、T2.Oppred、T1.CNTCTPRN、T2.CprCode、T2.MaxSumLoc，从OCRD T1左连接到T1.CardCode=T2.CardCode上的OOPR T2”，连接）；
适配器。填充（CardCode）；
如果（CardCode.Rows.Count>0）
{
对于（int i=0；i

您需要在Google上查找级联下拉列表。将两个下拉列表的AutoPostBack属性都设置为true。感谢您的回复，但此代码无法正常工作，因为我需要相同的列表

        protected void LoadOptions()
        {
            DataTable CardCode = new DataTable();
            string id, name, newName, name2;
            SqlConnection connection = new SqlConnection("Data Source=adfsadf;Initial Catalog=TestDatabse;Persist Security Info=True;User ID=asd;Password=asdf");
            using (connection)
            {
                SqlDataAdapter adapter = new SqlDataAdapter("SELECT T1.CardCode , T1.CardName, T2.OpprId,T1.CntctPrsn, T2.CprCode,T2.MaxSumLoc  FROM OCRD T1 left  join OOPR T2 on T1.CardCode=T2.CardCode" , connection);
                adapter.Fill(CardCode);
                if (CardCode.Rows.Count > 0)
                {
                    for (int i = 0; i < CardCode.Rows.Count; i++)
                    {

                        id = CardCode.Rows[i]["CardCode"].ToString();
                        name = CardCode.Rows[i]["CardName"].ToString();
                        newName = id + " ---- " + name;
                        //name2 = id;
                        DropDownList1.Items.Add(new ListItem(newName, id));

                        //*******HERE*****//
                        DropDownList2.DataSource = CardCode;
                        DropDownList2.DataBind();
                        DropDownList2.DataValueField = "CardCode";
                        DropDownList2.DataTextField = "CntctPrsn";

                        //*******HERE*****//
                    }
                }
            }
        }

        protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
        {


            string selected = DropDownList1.SelectedItem.Value;
            SqlConnection connection = new SqlConnection("Data Source=mydtasrc;Initial Catalog=TestDatabs;Persist Security Info=True;User ID=asf;Password=asdfgh");
            using (connection)
            {
                // SqlCommand theCommand = new SqlCommand("SELECT CardCode, CardName, OpprId, CprCode,MaxSumLoc  FROM OOPR WHERE CardCode = @CardCode", connection);

                SqlCommand theCommand = new SqlCommand("SELECT T1.CardCode , T1.CardName, T2.OpprId, T1.CntctPrsn,T2.CprCode  FROM OCRD T1 left  join OOPR T2 on T1.CardCode=T2.CardCode  where T1.CardCode=@CardCode", connection);


                connection.Open();
                theCommand.Parameters.AddWithValue("@CardCode", selected);
                theCommand.CommandType = CommandType.Text;

                SqlDataReader theReader = theCommand.ExecuteReader();

                if (theReader.Read())
                {
                    this.TextBox1.Text = theReader["CardCode"].ToString();
                    this.TextBox2.Text = theReader["CardName"].ToString();
                    this.TextBox5.Text = theReader["CprCode"].ToString();
                    this.TextBox3.Text = theReader["OpprId"].ToString();


                    //*******AND HERE*****//
                    this.DropDownList2.SelectedValue = selected; 

                    //*******AND HERE*****//
                }
                connection.Close();
            }

        }