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Persist Datagrid bindable usercontrol properties

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Grid

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

Basel Nimer asked on 17 May 2010, 04:28 PM

Hello All,

i honestly tried to find if this have been asked before but to no avail.

i have a user control that is bind-able to inside a GridTemplateColumn of a datagrid, it works fine and it displays the data, the problem is when the grid is sorted for example, all the data is lost.

i think i can solve this using a hidden control inside the usercontrol, but i am not sure yet, and i would like to know if there is something i am missing

to reproduce:
create user control:

    
            <%@ Control Language="VB" AutoEventWireup="false" CodeFile="X3.ascx.vb" Inherits="X3" %> 
        
            <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>

User control code behind:

    
            Partial Class X3 
        
                Inherits System.Web.UI.UserControl 
        
                Private _X3 As String 
        
                Public Property X3() As String 
        
                    Get 
        
                        Return _X3 
        
                    End Get 
        
                    Set(ByVal value As String) 
        
                        _X3 = value 
        
                    End Set 
        
                End Property 
        
                Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load 
        
                    Label1.Text = _X3 
        
                End Sub 
        
            End Class

Page:

    
            <%@ Page Language="VB" AutoEventWireup="false" CodeFile="ControlState.aspx.vb" Inherits="ControlState" %> 
        
            <%@ Register Assembly="Telerik.Web.UI" Namespace="Telerik.Web.UI" TagPrefix="telerik" %> 
        
            <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 
        
            <%@ Register Src="X3.ascx" TagName="X3" TagPrefix="uc1" %> 
        
            <html xmlns="http://www.w3.org/1999/xhtml" > 
        
            <head runat="server"> 
        
                <title>Untitled Page</title> 
        
            </head> 
        
            <body> 
        
                <form id="form1" runat="server"> 
        
                    <telerik:RadScriptManager ID="RadScriptManager1" runat="server"> 
        
                    </telerik:RadScriptManager> 
        
                <div> 
        
                    <telerik:RadGrid ID="RadGrid1" runat="server" GridLines="None" AllowSorting="True" AutoGenerateColumns="False" EnableViewState ="true" > 
        
                        <MasterTableView> 
        
                            <RowIndicatorColumn> 
        
                                <HeaderStyle Width="20px" /> 
        
                            </RowIndicatorColumn> 
        
                            <ExpandCollapseColumn> 
        
                                <HeaderStyle Width="20px" /> 
        
                            </ExpandCollapseColumn> 
        
                            <Columns> 
        
                                <telerik:GridBoundColumn UniqueName="X1" DataField="X1" HeaderText="X1"> 
        
                                </telerik:GridBoundColumn> 
        
                                <telerik:GridBoundColumn UniqueName="X2" DataField="X2" HeaderText="X2"> 
        
                                </telerik:GridBoundColumn> 
        
                                <telerik:GridTemplateColumn UniqueName="X3" DataField="X3" HeaderText="X3" SortExpression="X3"> 
        
                                    <ItemTemplate> 
        
                                        <uc1:X3 ID="X3_1" runat="server" X3='<%# Eval("X3") %>' /> 
        
                                    </ItemTemplate> 
        
                                </telerik:GridTemplateColumn> 
        
                                <telerik:GridBoundColumn UniqueName="X4" DataField="X4" HeaderText="X4"> 
        
                                </telerik:GridBoundColumn> 
        
                            </Columns> 
        
                        </MasterTableView> 
        
                    </telerik:RadGrid> 
        
                </div> 
        
                </form> 
        
            </body> 
        
            </html>

Page code behind:

    
            Imports Telerik.Web.UI 
        
            Partial Class ControlState 
        
                Inherits System.Web.UI.Page 
        
                Private Sub RadGrid1_NeedDataSource(ByVal [source] As Object, _ 
        
                         ByVal e As GridNeedDataSourceEventArgs) _ 
        
                         Handles RadGrid1.NeedDataSource 
        
                    Dim list As New ArrayList 
        
                    For i As Integer = 0 To 4 
        
                        Dim v As New D 
        
                        v.X1 = "V" & i.ToString & "_X1" 
        
                        v.X2 = "V" & i.ToString & "_X2" 
        
                        v.X3 = "V" & i.ToString & "_X3" 
        
                        v.X4 = "V" & i.ToString & "_X4" 
        
                        list.Add(v) 
        
                    Next 
        
                    RadGrid1.DataSource = list 
        
                End Sub 
        
                Private Class D 
        
                    Private _X1 As String 
        
                    Public Property X1() As String 
        
                        Get 
        
                            Return _X1 
        
                        End Get 
        
                        Set(ByVal value As String) 
        
                            _X1 = value 
        
                        End Set 
        
                    End Property 
        
                    Private _X2 As String 
        
                    Public Property X2() As String 
        
                        Get 
        
                            Return _X2 
        
                        End Get 
        
                        Set(ByVal value As String) 
        
                            _X2 = value 
        
                        End Set 
        
                    End Property 
        
                    Private _X3 As String 
        
                    Public Property X3() As String 
        
                        Get 
        
                            Return _X3 
        
                        End Get 
        
                        Set(ByVal value As String) 
        
                            _X3 = value 
        
                        End Set 
        
                    End Property 
        
                    Private _X4 As String 
        
                    Public Property X4() As String 
        
                        Get 
        
                            Return _X4 
        
                        End Get 
        
                        Set(ByVal value As String) 
        
                            _X4 = value 
        
                        End Set 
        
                    End Property 
        
                End Class 
        
            End Class

4 Answers, 1 is accepted

answered on 20 May 2010, 08:29 AM

Hello Basel,

One possible solution could be to change the property of the user control to look as follow:

01.Partial Class X3

02. Inherits System.Web.UI.UserControl

03.

04. Public Property X3() As String

05. Get

06. Return Label1.Text

07. End Get

08. Set(ByVal value As String)

09. Label1.Text = value

10. End Set

11. End Property

12.

13. Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

14. 'Label1.Text = X3

15. End Sub

16.

17.End Class

Regards,
Nikolay
the Telerik team

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answered on 21 May 2010, 03:17 PM

Hello Basel,

The behavior is due to lifecycle of the controls. The property in the user control is set only on Databinding. However on postback RadGrid won't bind before Page.Load and the value will remain empty.

Event more elegant solution could be if you handle DataBinding event and then set the value for the Label control.

01.Partial Class X3

02. Inherits System.Web.UI.UserControl

03.

04. Private _X3 As String

05. Public Property X3() As String

06. Get

07. Return _X3

08. End Get

09. Set(ByVal value As String)

10. _X3 = value

11. End Set

12. End Property

13.

14. Protected Sub LabelBinding(ByVal sender As Object, ByVal e As System.EventArgs) Handles Label1.DataBinding

15. Label1.Text = X3

16. End Sub

17.End Class

Greetings,
Nikolay
the Telerik team