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Populate ComboBox in RadGrid at runtime

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GridView

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

Sameers asked on 09 Mar 2009, 11:23 AM

I have a scenario where I need to populate a combobox in a cell based on the selection of another cell's combo box. That is, for example, there is a ShippingCarrier (UPS, USPS, FedEx etc) and when user select one of them, it should populate next cell's combo box with their services (for example, if UPS is selected, UPS Priority, UPS Next Day Air etc should be available in second column).

I am using UnBound grid. My code seems to work, HOWEVER, when data is populated in second column, you can not drop down 2nd combo box using mouse (the only way to drop down is to put cursor on second drop down and use ALT+Down Arrow key). Below is the code I am using.

                            col = AppendNewColumn(ColumnType.DropDown, 100, "Carrier", "Carrier")         
                    Dim cCol As GridViewComboBoxColumn = CType(col, GridViewComboBoxColumn)         
                    cCol.DataSource = GetShippingCarriers()         
                    cCol.DisplayMember = "Display"         
                    cCol.ValueMember = "Key"         

AppendNewColumn is the function which creates column and add that to columns collection of Grid. next you can see that it get shipping carriers and bind to that.

Now in CellEndEdit event, I am trying to populate second column as below.

                     Private Sub grdMain_CellEndEdit(ByVal sender As Object, ByVal e As Telerik.WinControls.UI.GridViewCellEventArgs) Handles grdMain.CellEndEdit         
                  If e.ColumnIndex = 12 Then 'Shipping Carrier Selected        
                        Dim row As GridViewRowInfo = Me.grdMain.Rows(e.RowIndex)         
                        Dim newCarrier As String = row.Cells(e.ColumnIndex).Value.ToString         
                        If newCarrier IsNot Nothing AndAlso newCarrier <> "" Then 
                            'Next column is Shipping Method (e.ColumnIndex + 1)        
                            Dim cellElem As GridComboBoxCellElement = CType(row.Cells(e.ColumnIndex + 1).CellElement, GridComboBoxCellElement)         
                            Debug.Write(cellElem.ToString)         
                     
                            Dim col As GridViewDataColumn = CType(cellElem.ColumnInfo, GridViewDataColumn)         
                     
                            Dim element As New RadComboBoxElement         
                            ServiceInfo.UPSServices.ToArray()         
                            element.DataSource = GetShippingServices(CType(CInt(newCarrier), ShippingCarriers))         
                            element.DisplayMember = "DisplayName"         
                     
                            element.StretchHorizontally = True         
                            element.StretchVertically = True         
                            element.DropDownStyle = Telerik.WinControls.RadDropDownStyle.DropDownList         
                     
                            For Each obj As Object In cellElem.Children         
                                If TypeOf obj Is ComboBoxEditorLayoutPanel Then         
                                    cellElem.Children.Remove(CType(obj, ComboBoxEditorLayoutPanel))         
                                End If         
                            Next         
                            'cellElem.Children.Clear()         
                            cellElem.Children.Add(element)         
                     
                            Debug.Write(col.FieldName)         
                        End If         
                    End If         

Is there anything wrong with the above code that drop down is NOT selected correctly using mouse?

Also, as you can see that I am binding using name/value pair, however, from the cell object, I can get only Value, is there any way to get SelectedItem (Drop down item selected) which may further give me Text and Value? For example, row.Cells(e.ColumnIndex).Value.ToString returns value (numeric), however, display thing is Text (USPS, UPS etc). Is there any way to get either DisplayName or ValueMember value?

Thanks,

Sameers

5 Answers, 1 is accepted

answered on 12 Mar 2009, 08:20 AM

Hi Sameers (theAngrycodeR),

Thank you for writing.

I have reviewed your code and in my opinion, changing the ComboBoxElement is not a good practice. Such approach could be difficult and can bring issues like described. Please, allow me to suggest a different way. You can use the ValueChanged event of the ComboBoxElement from your first column and implement custom filtering/populating code for the second ComboBox column depending on the selected value. You can subscribe to ValueChanged event by using RadGridView EditorRequired event. Also you can easily handle the chosen ValueMember and DisplayMember of the grid ActiveEditor property. Please, review the code-block below:

    
            Private Sub radGridView1_EditorRequired(ByVal sender As Object, ByVal e As Telerik.WinControls.UI.EditorRequiredEventArgs)   
        
                If e.EditorType Is GetType(RadComboBoxEditor) Then   
        
                    AddHandler DirectCast(e.Editor, RadComboBoxEditor).ValueChanged, AddressOf Editor_ValueChanged   
        
                End If   
        
            End Sub   
        
            Private Sub Editor_ValueChanged(ByVal sender As Object, ByVal e As EventArgs)   
        
                If Me.radGridView1.CurrentCell.ColumnIndex = 3 Then   
        
                    Dim selectedValue As Object = DirectCast(Me.radGridView1.ActiveEditor, RadComboBoxEditor).SelectedValue   
        
                    Dim displayText As String = DirectCast(DirectCast(Me.radGridView1.ActiveEditor, RadComboBoxEditor).SelectedItem, RadComboBoxItem).Text   
        
                    'implement your custom filtering/populating code here  
        
                End If   
        
            End Sub

I hope your trial period is going fine. Do not hesitate to contact me again if you have other questions.

Best wishes,
Martin Vasilev
the Telerik team

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answered on 04 Sep 2013, 07:37 PM

Hi,

I'm using telerik rad controls and I've encountered roadblocks.

I've application that have RadGridView with multiple RadComboBox different datasource.

Questions:

How I'll bind a specific cell in RadGridView with ComboBox? Please see my codes below.

        private void grdTruck_CellBeginEdit(object sender, GridViewCellCancelEventArgs e)
        {
            DataTable dt = PopulateTruckList();

            GridViewComboBoxColumn comboCol = e.Column as GridViewComboBoxColumn;
            comboCol.DataSource = dt;

            ((GridViewComboBoxColumn)e.Column).DataSource = dt;
        }

This code bind all the Rad Combo and I want only the specific cell..

Thanks