我有一个记录更新页面，似乎填充了所有字段，但是下拉列表只列出该特定记录的数据，而不是列出其他学校名称和学生姓名。两个下拉列表是级联的，即选择学校名称ddl应该只列出学生ddl中来自该学校的学生。
非常感谢您对此的任何帮助，谢谢。
tours.aspx上的Gridview代码
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" AllowPaging="true" OnPageIndexChanging="GridView1_PageIndexChanging" OnEditCommand="EditAddress" PageSize="5">
<Columns>
<asp:HyperLinkField Text="Update" DataNavigateUrlFields="TourId" DataNavigateUrlFormatString="~/abcrud1/tours_update.aspx?TourId={0}" />
<asp:BoundField DataField="TourId" HeaderText="TourId" HtmlEncode="false" />
<asp:BoundField DataField="VisitorName" HeaderText="VisitorName" HtmlEncode="false" />
<asp:BoundField DataField="VisitorSchoolId" HeaderText="VisitorSchoolId" HtmlEncode="false" />
<asp:BoundField DataField="SchName" HeaderText="SchName" HtmlEncode="false" />
<asp:BoundField DataField="TourDate" HeaderText="TourDate" HtmlEncode="false" />
<asp:BoundField DataField="StudentId" HeaderText="StudentId" HtmlEncode="false" />
<asp:BoundField DataField="FirstName" HeaderText="FirstName" HtmlEncode="false" />
<asp:BoundField DataField="LastName" HeaderText="LastName" HtmlEncode="false" />
</Columns>
</asp:GridView>
tour_update.aspx
<form id="form1" runat="server">
<div>
<table style="width: 50%;">
<tr>
<td style="width: 50%;">Tour Id:</td>
<td style="width: 50%;">
<asp:TextBox ID="txttourid" runat="server"></asp:TextBox></td>
</tr>
<tr>
<td style="width: 50%;">Visitor Name:</td>
<td style="width: 50%;">
<asp:TextBox ID="txtvisname" runat="server"></asp:TextBox></td>
</tr>
<tr>
<td style="width: 50%;">Visitor School:</td>
<td style="width: 50%;">
<asp:DropDownList ID="ddlvisschool" runat="server" AutoPostBack="true"></asp:DropDownList></td>
</tr>
<tr>
<td style="width: 50%;">Tour Date:</td>
<td style="width: 50%;">
<asp:TextBox ID="txttourdate" runat="server"></asp:TextBox></td>
</tr>
<tr>
<td style="width: 50%;">Student:</td>
<td style="width: 50%;">
<asp:DropDownList ID="ddlstudent" runat="server"></asp:DropDownList></td>
</tr>
<tr>
<td><asp:Button ID="btnUpdate" Text="Update" runat="server" OnClick="TourUpdate_click" /></td>
<td></td>
</tr>
</table>
</div>
</form>
tour_update.aspx.cs
{
public partial class tours_update : System.Web.UI.Page
{
string constr = ConfigurationManager.ConnectionStrings["SQLConnectionString2"].ConnectionString;
protected void Page_Load(object sender, EventArgs e)
{
{
if (!IsPostBack)
{
this.GetTour();
}
}
}
protected void TourUpdate_click(object sender, EventArgs e)
{
this.TourUpdate();
}
private int id
{
get
{
return !string.IsNullOrEmpty(Request.QueryString["TourId"]) ? int.Parse(Request.QueryString["TourId"]) : 0;
}
}
private void TourUpdate()
{
using (SqlConnection con = new SqlConnection(constr))
{
using (SqlCommand cmd = new SqlCommand("UPDATE tblCRUD1_Tour SET VisitorName=@VisitorName, VisitorSchoolId=@VisitorSchoolId, TourDate=@TourDate, StudentId=@StudentId WHERE TourId=@TourId", con))
{
cmd.Parameters.AddWithValue("@TourId", id);
cmd.Parameters.AddWithValue("@VisitorName", txtvisname.Text);
cmd.Parameters.AddWithValue("@VisitorSchoolId", ddlvisschool.SelectedItem.Value);
cmd.Parameters.AddWithValue("@TourDate", txttourdate.Text);
cmd.Parameters.AddWithValue("@StudentId", ddlstudent.SelectedItem.Value);
con.Open();
cmd.ExecuteNonQuery();
con.Close();
Response.Redirect("~/abcrud1/tours.aspx");
}
}
}
private void GetTour()
{
using (SqlConnection con = new SqlConnection(constr))
{
using (SqlCommand cmd = new SqlCommand(@"SELECT tblCRUD1_Tour.TourId, tblCRUD1_Tour.VisitorName, tblCRUD1_Tour.VisitorSchoolId, tblCRUD1_School.SchName, tblCRUD1_Tour.TourDate, tblCRUD1_Tour.StudentId, tblCRUD1_Student.FirstName, tblCRUD1_Student.LastName
FROM tblCRUD1_Tour
INNER JOIN tblCRUD1_Student ON tblCRUD1_Tour.StudentId = tblCRUD1_Student.StudentId
INNER JOIN tblCRUD1_School ON tblCRUD1_Student.LastSchoolId = tblCRUD1_School.SchId
WHERE tblCRUD1_Tour.TourId=@TourId", con))
{
cmd.Parameters.AddWithValue("@TourId", id);
using (SqlDataAdapter da = new SqlDataAdapter(cmd))
{
DataTable dt = new DataTable();
da.Fill(dt);
foreach (DataRow dr in dt.Rows)
{
this.txttourid.Text = dr["TourId"].ToString();
this.txtvisname.Text = dr["VisitorName"].ToString();
this.txttourdate.Text = dr["TourDate"].ToString();
ddlvisschool.DataSource = dt;
ddlvisschool.DataTextField = "SchName";
ddlvisschool.DataValueField = "VisitorSchoolId";
ddlvisschool.DataBind();
ddlstudent.DataSource = dt;
ddlstudent.DataTextField = "LastName";
ddlstudent.DataValueField = "StudentId";
ddlstudent.DataBind();
}
}
}
}
}
}
}
tours_add.aspx.cs
{
public partial class tours_add : System.Web.UI.Page
{
SqlConnection con = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["SQLConnectionString2"].ConnectionString);
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
Bindddlvisschool();
ddlstudent.Items.Insert(0, " Select Pupil ");
}
}
private void Bindddlvisschool()
{
con.Open();
string str = @"Select * FROM tblCRUD1_School ORDER BY SchName ASC";
SqlCommand cmd = new SqlCommand(str, con);
SqlDataAdapter da = new SqlDataAdapter(cmd);
DataTable dt = new DataTable();
da.Fill(dt);
ddlvisschool.DataSource = dt;
ddlvisschool.DataTextField = "SchName";
ddlvisschool.DataValueField = "SchId";
ddlvisschool.DataBind();
ddlvisschool.Items.Insert(0, new ListItem(" Choose Last School ", "0"));
ddlvisschool.SelectedIndex = 0;
con.Close();
}
protected void TourAdd_click(object sender, EventArgs e)
{
con.Open();
string str = @"INSERT INTO tblCRUD1_Tour (VisitorName,VisitorSchoolId,TourDate,StudentId) VALUES (@VisitorName,@VisitorSchoolId,@TourDate,@StudentId)";
SqlCommand cmd = new SqlCommand(str, con);
cmd.Parameters.AddWithValue("@VisitorName", txtvisname.Text);
cmd.Parameters.AddWithValue("@VisitorSchoolId", ddlvisschool.Text);
cmd.Parameters.AddWithValue("@TourDate", txttourdate.Text);
cmd.Parameters.AddWithValue("@StudentId", ddlstudent.Text);
cmd.ExecuteNonQuery();
lblmessage1.Text = "Tour added successfully";
con.Close();
Response.AddHeader("REFRESH", "3;URL=tours.aspx");
}
protected void ddlvisschool_SelectedIndexChanged(object sender, EventArgs e)
{
string get_SchId;
string get_SchName;
get_SchId = ddlvisschool.SelectedValue.ToString();
get_SchName = ddlvisschool.SelectedItem.Text;
if (get_SchId != "0")
{
con.Open();
SqlDataAdapter da;
DataSet ds = new DataSet();
string query;
query = "SELECT tblCRUD1_Tour.TourId, tblCRUD1_Tour.VisitorName, tblCRUD1_Tour.VisitorSchoolId, tblCRUD1_School.SchName, tblCRUD1_Tour.TourDate, tblCRUD1_Tour.StudentId, tblCRUD1_Student.FirstName, tblCRUD1_Student.LastName "
+ "FROM tblCRUD1_Tour "
+ "INNER JOIN tblCRUD1_Student ON tblCRUD1_Tour.StudentId = tblCRUD1_Student.StudentId "
+ "INNER JOIN tblCRUD1_School ON tblCRUD1_Student.LastSchoolId = tblCRUD1_School.SchId "
+ "WHERE tblCRUD1_Tour.VisitorSchoolId='" + get_SchId.ToString() + "' ORDER BY tblCRUD1_Student.LastName ASC";
da = new SqlDataAdapter(query, con);
da.Fill(ds);
if (ds.Tables[0].Rows.Count > 0)
{
ddlstudent.DataSource = ds;
ddlstudent.DataTextField = "LastName";
ddlstudent.DataValueField = "StudentId";
ddlstudent.DataBind();
//ddlstudent.Items.Insert(0, new ListItem(get_SchName.ToString(), "0"));
ddlstudent.SelectedIndex = 0;
}
else
{
ddlstudent.Items.Insert(0, "No Student");
ddlstudent.DataBind();
}
}
}
}
}