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Inconsistent results

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ListBox

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Joshua asked on 03 May 2010, 09:56 PM

001.png

002.png

003.png

Hello,

I have two list boxes (radFullList and radList) which are linked together for AllowTransfer. Not that it matters but the first listbox is a list of employee names, the value is their employee number. The second listbox is for holding the employee's supervisors so when you move an items from radFullList to radList it maintains the same format, employee name and employee number in the value.

EmployeeEditView.ascx

                    <telerik:RadListBox ID="radFullList" runat="server" AllowTransfer="True"          
                AllowTransferOnDoubleClick="true" EnableDragAndDrop="true" TransferToID="radList"          
                DataKeyField="GUID" DataSortField="EmployeeName" DataSourceID="LinqDS4"          
                DataTextField="EmployeeName" DataValueField="EmployeeNumber" Height="200px"          
                Width="200px">         
                <ButtonSettings ReorderButtons="Common"></ButtonSettings>         
            </telerik:RadListBox>         
            <telerik:radlistbox ID="radList" runat="server" Height="200px" Width="200px"          
                AllowReorder="true" AllowDelete="true" />         
            <asp:LinqDataSource ID="LinqDS4" runat="server"          
                ContextTypeName="Modules.EmployeeManagement.EmployeeManagementDataContext"          
                TableName="tblEmployees" OrderBy="EmployeeName" >         
            </asp:LinqDataSource>         

I have this wired up to a Save button in my Sitefinity Module.

EmployeeEditView.ascx.vb

                    Dim sb As New StringBuilder()         
            Dim db = New Modules.EmployeeManagement.EmployeeManagementDataContext         
            Dim employee = (From t In db.tblEmployees Where t.GUID = Me.DataItemId Select t).Single         
            employee.EmployeeName= txtName.Text         
            ...         
            employee.UserGroup = radUserGroup.SelectedValue         
            For Each item As RadListBoxItem In radList.Items         
                sb.Append(item.Value.ToString & "|")         
            Next         
            employee.SupervisorNumber = Left(sb.ToString, 59)         
            db.SubmitChanges()         
            Response.Redirect(CreateHostViewCommand("EmployeeEditView", DataItemId.ToString, Nothing))         

So as you can see all I am doing is a simple write from the form.

Scenario: This code works perfectly if the second listbox (radList) is empty. You add 1 or 2 employees to the second list box, hit save and the results written to the database are accurate.

If you go back in to this employee's account, you will see everything is correct. Instead of exiting, if you simply hit Save again all the entries in the second listbox, radList, are duplicated. Both times the same code is used since I am "Updating" the employee both times.

As a test to get screens for this post I edited an employee who has no supervisors. Which you can see in screenshot "001.png". Screenshot "002.png" is after adding two accounts as supervisors. The screenshot is taken after Save is clicked which means not only did it save to the database correctly, but it was loaded into the listbox correctly as well. Now in screenshot "003.png" is after clicking the Save button once more without performing any work with the listboxes. As you can see the two entries are repeated.

As far as I can tell from looking up documentation associated with RadListBox I am using the correct code to cycle through items. "For Each item As RadListBoxItem In radList.Items" Any help you can offer would be greatly appreciated.

6 Answers, 1 is accepted

answered on 14 May 2010, 02:46 PM

beforehittingsave.png

afterhittingsave.png

Hi Joshua,

This is interesting, can you try the following, after hitting save for the first time check the client state of the destination RadListBoxItem. This can be achieved with a tool like firebug. Select on the RadListBox body with the select pointer and check the client state. Please refer to the sceenshots attached for details.

Further, do you have any codebehind lines that rebind the destination RadListBox? Or any lines at all connected with DataBinding the RadListBoxes?

Best wishes,
Genady Sergeev
the Telerik team

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answered on 20 May 2010, 06:47 PM

firebug-after-save-loaded-items.png

firebug-before-save-empty.png

firebug-before-save-after-transfer.png

I believe I have what you are asking for with Firebug and it appears I am doing something wrong as the you will see in the screenshots.

I do have code that rebind the listbox. The data is stored in a text field like so "12345|23456|34567|67890" so I have a process which splits these into an array and then loop through the array to bind to the listbox. Shown below:

                                Try         
                            Dim strSupervisors As String = employee.SupervisorNumber         
                            Dim arrSupervisors As Array = Split(strSupervisors, "|")         
                            PopulateItems(radList, arrSupervisors)         
                        Catch ex As Exception         
                            DebugInfo("radList: " & ex.Message)         
                        End Try         

                        Private Shared Sub PopulateItems(ByVal listBox As RadListBox, ByVal array As Array)         
                    For x As Integer = 0 To UBound(array) - 1         
                        If Len(array(x)) > 5 Then         
                            Dim item As New RadListBoxItem(GetUsernameFromEmployeeNumber(array(x)), array(x))         
                            listBox.Items.Add(item)         
                        End If         
                    Next         
                End Sub         

                        Private Shared Function GetUsernameFromEmployeeNumber(ByVal strEmployeeNumber As String) As String         
                    Dim strReturn As String = ""         
                    Try         
                        Dim db = New Modules.EmployeeManagement.EmployeeManagementDataContext         
                        Dim employee = (From t In db.tblAuthors Where t.EmployeeNumber = strEmployeeNumber Select t).Single         
                        strReturn = employee.Username         
                    Catch ex As Exception         
                        strReturn = ex.Message         
                    End Try         
                    Return strReturn         
                End Function         

answered on 25 May 2010, 08:03 AM

Hi Joshua,

The screenshots looks correct. This is the way the client state should look before and after hitting save. I.e. it should have values in the log entry before save and empty log after that. It seems that the problem comes from the way the listboxes are rebound. There is no need to add the items manually after they were first added. RadListBox will "remember" that there are items transferred. I suggest that you revise your server-side code and more specifically the PopulateItems method. You shouldn't invoke it on Save click. Where do you call that method and when?

Kind regards,
Genady Sergeev
the Telerik team

answered on 25 May 2010, 08:04 AM

Hi Joshua,

The screenshots looks correct. This is the way the client state should look before and after hitting save. I.e. it should have values in the log entry before save and empty log after that. It seems that the problem comes from the way the listboxes are rebound. There is no need to add the items manually after they were first added. RadListBox will "remember" that there are items transferred. I suggest that you revise your server-side code and more specifically the PopulateItems method. You shouldn't invoke it on Save click. Where and when do you call that method?

Kind regards,
Genady Sergeev
the Telerik team