CODEWITHSUNDEEP
c#asp.net
Manisha Bano
Manisha Bano

Reputation: 1903

OnSelectedIndexChanged event not working

i am trying to get data from the stored procedure into the dropdownlist when the event onSelectIndexChanged is fired. But after putting the break point i get to know that the event generated is not working i.e. the control doesnot even goes into that code.

 <tr>
        <td><asp:Label ID="Label5" runat="server" Text="Book Category"></asp:Label></td>
        <td>
            <asp:DropDownList ID="ddlBookCategory" runat="server" Height="20px" Width="250px" OnSelectedIndexChanged="ddlBookCategory_SelectedIndexChanged"  >
            </asp:DropDownList>
        </td>
    </tr>
    <tr>
        <td><asp:Label ID="Label4" runat="server" Text="Book Subject"></asp:Label></td>
        <td>
            <asp:DropDownList ID="ddlBookSubject" runat="server" Height="20px" Width="250px" >
            </asp:DropDownList>
        </td>
    </tr>

and the backend cs file coding is::

 protected void Page_Load(object sender, EventArgs e)
{


     connectionString = ConfigurationManager.ConnectionStrings["connectionString"].ToString();
     lblmsg.Visible = false;

     OleDbConnection con = new OleDbConnection(connectionString);
     OleDbCommand cmd = new OleDbCommand();

     try
     {
         con.Open();
         cmd.CommandType = System.Data.CommandType.StoredProcedure;

         cmd.CommandText = "ShowBookCategory";
         cmd.Connection = con;



         OleDbDataReader reader = cmd.ExecuteReader();


         if (reader.HasRows)
         {
             while (reader.Read())
             {
                 ddlBookCategory.Items.Add(new ListItem(reader["CategoryName"].ToString()));
             }
         }

     }
     catch (OleDbException ex)
     {
         ex.Data.ToString();
     } 
}


 protected void ddlBookCategory_SelectedIndexChanged(object sender, EventArgs e)
{
    ddlBookCategory.AutoPostBack = true;
    OleDbConnection con = new OleDbConnection(connectionString);
    OleDbCommand cmd2 = new OleDbCommand();
    MbERPLibraryBookSubjectProperty foc = new MbERPLibraryBookSubjectProperty();

    try
    {
        con.Open();
        cmd2.CommandType = System.Data.CommandType.StoredProcedure;
        cmd2.CommandText = "ShowBookSubjectWithCategory";
        cmd2.Connection = con;

        foc.CategoryName = ddlBookCategory.Text.ToString();
        cmd2.Parameters.Add(new OleDbParameter("@CategoryName", foc.CategoryName));
        cmd2.Parameters["@CategoryName"].Direction = System.Data.ParameterDirection.Input;

        OleDbDataReader reader2 = cmd2.ExecuteReader();
        if (reader2.HasRows)
        {
            while (reader2.Read())
            {
                ddlBookSubject.Items.Add(new ListItem(reader2["SubjectName"].ToString()));
            }
        }

    }
    catch (OleDbException ex)
    {
        ex.Data.ToString();
    } 
}

And my stored Procedure is:

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER Procedure [dbo].[ShowBookSubjectWithCategory](
    @CategoryName varchar(50)
    )
AS
BEGIN
select * from BookSubjects Where CategoryName = @CategoryName
END

Upvotes: 1

Views: 500

Answers (3)

davidallyoung
davidallyoung

Reputation: 1332

You need to add AutoPostBack =true to the control in order for the control to signal back to the server that an event has occurred. Once you do that you can set an event handler to a method in your code behind for the selected index changed event on that control.

Upvotes: 0

HaMi
HaMi

Reputation: 539

Instead of declaring autoPostBack as true in your event handler, try to set it in DropDownList declaration like bellow:

<asp:DropDownList ID="ddlBookCategory" ... autopostback="true" ... >
...
</asp:DropDownList>

Upvotes: 1

Sushmit Patil
Sushmit Patil

Reputation: 1465

If you want to set ddlBookCategory.AutoPostBack = true; dynamically then set that in pageload event.

Upvotes: 1

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