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Object reference not set to an instance of an object.

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Grid

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

dingen asked on 02 Jan 2010, 06:28 AM

Hi

I have build a grid with a formtemplate. I want to set the label text through a button click. The problem is that it cant find the reference to the label. What to do?

reg
D

    
            <%@ Page Language="VB" AutoEventWireup="false" CodeFile="Itemcommand.aspx.vb" Inherits="Itemcommand" %> 
        
            <%@ 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"> 
        
            <html xmlns="http://www.w3.org/1999/xhtml"> 
        
            <head runat="server"> 
        
                <title></title> 
        
            </head> 
        
            <body> 
        
                <form id="form1" runat="server"> 
        
                <div> 
        
                    <telerik:RadScriptManager runat="server"> 
        
                    </telerik:RadScriptManager> 
        
                    <telerik:RadGrid ID="RadGrid1" runat="server"  GridLines="None" 
        
                         AutoGenerateColumns="False" 
        
                        ShowStatusBar="True" DataSourceID="SqlDataSource1"> 
        
                        <MasterTableView CommandItemDisplay="TopAndBottom" GridLines="None" DataKeyNames="EmployeeID" 
        
                            AllowFilteringByColumn="False" AllowSorting="True" DataSourceID="SqlDataSource1"> 
        
                            <Columns> 
        
                                <telerik:GridEditCommandColumn UniqueName="EditCommandColumn"> 
        
                                </telerik:GridEditCommandColumn> 
        
                                <telerik:GridBoundColumn UniqueName="EmployeeID" HeaderText="EmployeeID" DataField="EmployeeID" 
        
                                    DataType="System.Int32" ReadOnly="True" SortExpression="EmployeeID"> 
        
                                </telerik:GridBoundColumn> 
        
                                <telerik:GridBoundColumn DataField="City" HeaderText="City" SortExpression="City" 
        
                                    UniqueName="City"> 
        
                                </telerik:GridBoundColumn> 
        
                                <telerik:GridBoundColumn DataField="Country" HeaderText="Country" SortExpression="Country" 
        
                                    UniqueName="Country"> 
        
                                </telerik:GridBoundColumn> 
        
                            </Columns> 
        
                            <EditFormSettings EditFormType="Template"> 
        
                                <EditColumn UniqueName="EditCommandColumn1"> 
        
                                </EditColumn> 
        
                                <FormTemplate> 
        
                                    <table id="Table3" cellspacing="1" cellpadding="1" width="250" border="0" class="module"> 
        
                                        <tr> 
        
                                            <td> 
        
                                            </td> 
        
                                            <td> 
        
                                            </td> 
        
                                        </tr> 
        
                                        <tr> 
        
                                            <td> 
        
                                                Country: 
        
                                            </td> 
        
                                            <td> 
        
                                                <asp:TextBox ID="TextBox7" runat="server" Text='<%# Bind( "Country"  ) %>'> 
        
                                                </asp:TextBox> 
        
                                            </td> 
        
                                        </tr> 
        
                                        <tr> 
        
                                            <td> 
        
                                                City: 
        
                                            </td> 
        
                                            <td> 
        
                                                <asp:TextBox ID="TextBox8" runat="server" Text='<%# Bind( "City") %>' TabIndex="1"> 
        
                                                </asp:TextBox> 
        
                                            </td> 
        
                                        </tr> 
        
                                        <tr> 
        
                                            <td> 
        
                                                <asp:Button ID="btnTest" CommandName="test" text="go" runat="server" /> 
        
                                                <asp:Label ID="lb1" runat="server"></asp:Label> 
        
                                            </td> 
        
                                        </tr> 
        
                                    </table> 
        
                                    </table> 
        
                                </FormTemplate> 
        
                            </EditFormSettings> 
        
                        </MasterTableView> 
        
                    </telerik:RadGrid> 
        
                </div> 
        
                <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:nwindConnectionString %>" 
        
                    ProviderName="<%$ ConnectionStrings:nwindConnectionString.ProviderName %>" SelectCommand="SELECT * FROM [Employees]"> 
        
                </asp:SqlDataSource> 
        
                </form> 
        
            </body> 
        
            </html>

    
            Imports Telerik.Web.UI 
        
            Partial Class Itemcommand 
        
                Inherits System.Web.UI.Page 
        
                Protected Sub RadGrid1_ItemCreated1(ByVal sender As Object, ByVal e As Telerik.Web.UI.GridItemEventArgs) Handles RadGrid1.ItemCreated 
        
                    If e.Item.ItemType = GridItemType.EditFormItem And e.Item.IsInEditMode Then 
        
                        Dim testbut As Button = CType(e.Item.FindControl("btnTest"), Button) 
        
                        Dim lbref As Label = CType(e.Item.FindControl("lb1"), Label) 
        
                        AddHandler testbut.Click, AddressOf testbutclicked 
        
                    End If 
        
                End Sub 
        
                Protected Sub testbutclicked(ByVal sender As Object, ByVal e As EventArgs) 
        
                    Dim lb As Label = RadGrid1.FindControl("lb1") 
        
                    lb.Text = "hi" 
        
                End Sub 
        
            End Class

1 Answer, 1 is accepted

answered on 04 Jan 2010, 06:05 AM

Hi,

You can try the following code in order to set the Label text when clicking the button in FormTemplate.

VB:

    
            Protected Sub RadGrid1_ItemCreated(ByVal sender As Object, ByVal e As GridItemEventArgs) 
        
                If e.Item.ItemType = GridItemType.EditFormItem And e.Item.IsInEditMode Then 
        
                    Dim testbut As Button = DirectCast(e.Item.FindControl("btnTest"), Button) 
        
                    AddHandler testbut.Click, AddressOf testbut_Click 
        
                End If 
        
            End Sub 
        
            Private Sub testbut_Click(ByVal sender As Object, ByVal e As EventArgs) 
        
                Dim btn As Button = DirectCast(sender, Button) 
        
                Dim editItem As GridEditFormItem = DirectCast(btn.NamingContainer, GridEditFormItem) 
        
                Dim lbref As Label = DirectCast(editItem.FindControl("lb1"), Label) 
        
                lbref.Text = "hi" 
        
            End Sub

Also you can try the following code in ItemCommand event of grid in order to perform same functionality.
VB:

    
            Protected Sub RadGrid1_ItemCommand(ByVal source As Object, ByVal e As GridCommandEventArgs)  
        
                If e.CommandName = "test" Then  
        
                    Dim edititem As GridEditFormItem = DirectCast(TryCast(e.Item, GridDataItem).EditFormItem, GridEditFormItem)  
        
                    Dim lbl As Label = DirectCast(edititem.FindControl("lb1"), Label)  
        
                    lbl.Text = "hi"  
        
                End If  
        
            End Sub

-Shinu.