VB.NET下拉列表未填充所有项目

Question

I am populating an asp dropdown list by reading data from a MySQL table via stored procedure.

The data reader returns all 4 rows from the table however only rows 2, 3, 4 are listed in the dropdown list.

This is the code that sets the dropdown list. Does anyone have any ideas on what may have gone wrong?

Thanks

 Try
        Dim conn As New MySql.Data.MySqlClient.MySqlConnection(myConnectionString)
        Dim cmd As New MySqlCommand()

        conn.Open()
        cmd.Connection = conn
        cmd.CommandText = "Select_CatLibraryData"
        cmd.CommandType = CommandType.StoredProcedure

        Using catdata_rs As MySqlDataReader = cmd.ExecuteReader()

            If catdata_rs.Read() Then
                list_itemcategory.DataSource = catdata_rs
                list_itemcategory.DataValueField = "category"
                list_itemcategory.DataTextField = "category"
                list_itemcategory.DataBind()
            End If

        End Using

    Catch ex As MySql.Data.MySqlClient.MySqlException

        lbl_ErrorPanelText.Text = "Error establishing a database connection!"
        pn_ErrorPanel.Visible = True

    End Try

Answer 1

You should not use If catdata_rs.Read() since it advances the pointer by 1.

Instead use code like below. Or you could just remove the surrounding if around databinding code and directly bind to data reader and if its empty then your list drop down will also be empty.

If catdata_rs.HasRows Then
            list_itemcategory.DataSource = catdata_rs
            list_itemcategory.DataValueField = "category"
            list_itemcategory.DataTextField = "category"
            list_itemcategory.DataBind()
End If