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RadComboBox Bound to string[] Not Selecting Specified Value

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ComboBox

This is a migrated thread and some comments may be shown as answers.

kevin floyd asked on 25 May 2010, 05:18 PM

I have a RadGrid with an EditForm containing a RadComboBox. The RadComboBox has a datasource set to a string[] (DataSource='<%# GetSampleValues() %>'). When creating and editing a record, the combobox displays the correct strings in the dropdown list. When Editing an existing record, the selected string before expanding the combobox is not displaying the appropriate value.

                    <rad:RadComboBox ID="rcb_SampleValues" runat="server" AllowCustomText="false"         
               DataSource='<%# GetSampleValues() %>'          
               Text='<%# Bind("SampleValueString") %>'         
               Value='<%# Bind("SampleValueString") %>'         
               MaxLength="255"          
               Width="100" >         
            </rad:RadComboBox>         

                    public enum SampleValues         
            {         
                 SampleValue1,         
                 SampleValue2         
            }
            
                                                                public class Samples                     
                        {                     
                             public int ID { get; set; }                     
                             public string Name { get; set; }                     
                             public SampleValues SampleValue { get; set; }                     
                             public string SampleValueString { get; set; }                     
                        }                    
                                

                    public void Page_Load(object sender, EventArgs e)
            {
            BindGridData();
            }
            
            public void BindDataGrid()
            {
            Samples[] samples = GetObjectsFromDataAccessLayer()
            radGrid.DataSource = samples;
            }
                    
            public static string[] GetSampleValues()         
            {         
                 return Enum.GetNames(typeof(SampleValues));         
            }         

I am binding the RadComboBox to an array of strings which are generated off of an Enum - but the same problem happens when I bind the RadCombobBox to a set of objects and set the DataTextMember and DataValueMember. I have a sample application that I can send to someone that would like to see it.

Any ideas on what is not being done to make the comboBox NOT set to the intended value when the record is loaded?

6 Answers, 1 is accepted

answered on 26 May 2010, 09:41 AM

Hello kevin,

As I see the problem is that you are binding the Value of the RadComboBox to a non-unique value:

<rad:RadComboBox ID="rcb_SampleValues" runat="server" AllowCustomText="false"

DataSource='<%# GetSampleValues() %>'

Text='<%# Bind("SampleValueString") %>'

Value='<%# Bind("SampleValueString") %>'

MaxLength="255"

Width="100" >

</rad:RadComboBox>

Please take a look at this help topic when RadComboBox selects a different item.

If you still have some questions please send us the full code and we can help you.

Kind regards,
Veronica Milcheva
the Telerik team

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answered on 27 May 2010, 02:28 PM

Ok... I have made a sample web application that exhibits the same behavior I am seeing in my live application. There are 3 files: Objects.cs, Default.aspx, Default.aspx.cs.

Objects.cs:

                    namespace StringsComboBoxExample         
            {         
                public enum SampleValues         
                {         
                    SampleValue1,         
                    SampleValue2         
                }         
                     
                public class Samples         
                {         
                    public int ID { get; set; }         
                    public string Name { get; set; }         
                    public SampleValues SampleValue { get; set; }         
                    public string SampleValueString { get; set; }         
                }         
            }         

Default.aspx:

                    <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="StringsComboBoxExample._Default" %>         
                     
            <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">         
                     
            <%@ Register Assembly="RadGrid.Net2" Namespace="Telerik.WebControls" TagPrefix="rad" %>         
            <%@ Register Assembly="RadComboBox.Net2" Namespace="Telerik.WebControls" TagPrefix="rad" %>         
                     
            <html xmlns="http://www.w3.org/1999/xhtml" >         
            <head runat="server">         
                <title></title>         
            </head>         
            <body>         
                <form id="form1" runat="server">         
                <div>         
                    <rad:RadGrid ID="radGrid" runat="server" GridLines="None" PageSize="20" AllowSorting="true"          
                        AutoGenerateColumns="false" EnableAJAX="true" ShowStatusBar="false" Width="1000">         
                        <PagerStyle Mode="NextPrevAndNumeric" />         
                        <MasterTableView CommandItemDisplay="Bottom" GridLines="None" DataKeyNames="ID">         
                            <Columns>         
                                <rad:GridBoundColumn Display="true" UniqueName="Name" DataField="Name" HeaderText="Name" />         
                                <rad:GridBoundColumn Display="true" UniqueName="SampleValueString" DataField="SampleValueString" HeaderText="SampleValueString" />         
                                     
                                <rad:GridEditCommandColumn />         
                            </Columns>         
                            <EditFormSettings EditFormType="Template">         
                                <FormTemplate>         
                                    <div>         
                                        <table width="100%">         
                                            <tr>         
                                                <td align="left">         
                                                    <table>         
                                                    <tr>         
                                                        <td align="right"> Name:</td>         
                                                        <td><asp:TextBox ID="tbx_Name" runat="server" ValidationGroup="newField"         
                                                                MaxLength="50" Height="15" Width="100" Text='<%# Bind("Name") %>' />         
                                                            <asp:RequiredFieldValidator ID="rfv_NameRequired" runat="server" ErrorMessage="*" Text="*"          
                                                                SetFocusOnError="true" ControlToValidate="tbx_Name" ValidationGroup="newField" />         
                                                        </td>         
                                                        <td align="right"> Sample Value: </td>         
                                                        <td>         
                                                          <rad:RadComboBox ID="rcb_SampleValues" runat="server" AllowCustomText="false"         
                                                                DataSource='<%# GetSampleValues() %>' MaxLength="255" Text='<%# Bind("SampleValueString") %>'         
                                                                Width="100" ToolTip="Please select an Sample Values." ValidationGroup="newField">         
                                                          </rad:RadComboBox>         
                                                          <asp:RequiredFieldValidator ID="rfv_SampleValueValidator" runat="server" ErrorMessage="*"          
                                                                SetFocusOnError="true" ControlToValidate="rcb_SampleValues" ValidationGroup="newField" />         
                                                        </td>         
                                                    </tr>         
                                                    </table>         
                                                </td>         
                                                <td align="right">         
                                                    <asp:Button ID="btnUpdate" runat="server" CausesValidation="true" ValidationGroup="newField"         
                                                        Text='<%# (Container is GridEditFormInsertItem) ? "Insert" : "Update" %>'         
                                                        CommandName='<%# (Container is GridEditFormInsertItem) ? "PerformInsert" : "Update" %>'         
                                                        OnClick="Update_Clicked" >         
                                                    </asp:Button>         
                                                    <asp:HiddenField ID="hdn_ID" runat="server" Value='<%# Bind("ID") %>' />         
                                                    &nbsp;         
                                                    <asp:Button ID="btnCancel" Text="Cancel" runat="server" CausesValidation="False" CommandName="Cancel"></asp:Button><br />         
                                                </td>         
                                            </tr>         
                                        </table>                                 
                                    </div>                           
                                     
                                </FormTemplate>         
                            </EditFormSettings>         
                        </MasterTableView>         
                    </rad:RadGrid>         
                </div>         
                </form>         
            </body>         
            </html>         

Default.aspx.cs:

                    using System;         
            using System.Collections.Generic;         
            using System.Linq;         
            using System.Web;         
            using System.Web.UI;         
            using System.Web.UI.WebControls;         
                     
            using Telerik.Web.UI;         
                     
            namespace StringsComboBoxExample         
            {         
                public partial class _Default : System.Web.UI.Page         
                {         
                    List<Samples> _samples = null;         
                     
                    protected void Page_Load(object sender, EventArgs e)         
                    {         
                        BindGridData();         
                    }         
                     
                    protected void BindGridData()         
                    {         
                        _samples = new List<Samples>();         
                        Samples sample = new Samples();         
                        sample.Name = "Sample 1";         
                        sample.SampleValue = SampleValues.SampleValue1;         
                        sample.SampleValueString = Enum.GetName(typeof(SampleValues), sample.SampleValue);         
                        _samples.Add(sample);         
                     
                        sample.Name = "Sample 2";         
                        sample.SampleValue = SampleValues.SampleValue2;         
                        sample.SampleValueString = Enum.GetName(typeof(SampleValues), sample.SampleValue);         
                        _samples.Add(sample);         
                     
                        radGrid.DataSource = _samples.ToArray();         
                    }         
                     
                    public static string[] GetSampleValues()         
                    {         
                        return Enum.GetNames(typeof(SampleValues));         
                    }         
                     
                    protected void Update_Clicked(object sender, EventArgs e)         
                    {         
                        Button btn = sender as Button;         
                        if (btn == null) return;         
                        List<string> keys = new List<string>(Request.Params.AllKeys);         
                     
                        string idKey = keys.Find(x => x.EndsWith("hdn_ID"));         
                        string nameKey = keys.Find(x => x.EndsWith("tbx_Name"));         
                        string sampleValuesKey = keys.Find(x => x.EndsWith("rcb_SampleValues_text"));         
                     
                        Samples sample = new Samples();         
                        sample.Name = Request.Params[nameKey].Trim();         
                        sample.SampleValue = (SampleValues)Enum.Parse(typeof(SampleValues), Request.Params[sampleValuesKey]);         
                        sample.SampleValueString = Enum.GetName(typeof(SampleValues), sample.SampleValue);         
                     
                        _samples.Add(sample);         
                     
                        BindGridData();         
                        radGrid.Rebind();         
                    }         
                }         
            }         

answered on 01 Jun 2010, 05:28 PM

radcomboboxboundtostringarray.zip

Hello kevin floyd,

To be able to solve your problem you need to subscribe to the DataBound event on the RadComboBox:

<telerik:RadComboBox ID="rcb_SampleValues" runat="server" AllowCustomText="false" OnDataBound="rcb_SampleValues_DataBound"

DataSource='<%# GetSampleValues() %>' MaxLength="255" Text='<%# Bind("SampleValueString") %>'

Width="100" ToolTip="Please select an Sample Values." ValidationGroup="newField">

</telerik:RadComboBox>

and use this code in the handler:

protected void rcb_SampleValues_DataBound(object sender, EventArgs e)

{

((RadComboBox)sender).FindItemByText(((Samples)GetDataItem()).SampleValueString).Selected = true;

}

Find the edited code in the attached .zip file.

Hope this helps.

Regards,
Veronica Milcheva
the Telerik team

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RadComboBox Bound to string[] Not Selecting Specified Value

6 Answers, 1 is accepted