[Solved] Setting Cell content programmatically

[Nicolas Porto]

Hi,

I'm trying to set the content of a specific cell programmatically, can you help me please?

[Milan]

Hi Nicolas Porto,

For example, if you want to update the value of the first cell of the current row you can use the following code:

private void Button_Click(object sender, System.Windows.RoutedEventArgs e)

{

GridViewRow row = (GridViewRow)this.playersGrid.ItemsControl.ItemsGenerator.ContainerFromItem(this.playersGrid.CurrentItem);

GridViewCell firstCell = row.Cells[0] as GridViewCell;

firstCell.Value = "NewValue";

}

You should also use TwoWay binding for your column if you would like to update the underlying data item as well:

<telerik:RadGridView.Columns>

<telerik:GridViewDataColumn Header="Name" DataMemberBinding="{Binding Name, Mode=TwoWay}">

</telerik:GridViewDataColumn>

</telerik:RadGridView.Columns>

All the best,
Milan
the Telerik team

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[omar lara]

A lot of thanks for the quick response.

Regards

[Josh]

I'm following this example and although this lets me change the gridview cell's value without error, the underlying property that the column is bound to is not getting updated.  I do have two way binding set.

From the example, after clicking the button, checking firstCell.Value gives me back "NewValue", however, "PlayersGrid.Item(0).Name" returns me the old value.

I will gladly provide sample code if necessary however my test case is exactly the same as the example.  The only difference is that instead of "ItemsControl.ItemsGenerator", I'm using "ItemContainerGenerator".  I'm guessing the method changed.   Modifying the underlying object directly may be difficult since in my actual application the underlying object class is dynamically generated at run time.

Any help would be greatly appreciated.

Thanks,

-Josh

[Milan]

Hi Josh,

The better approach is to set properties on your data items instead of setting values on our UI elements. Could you please provide a sample project to find out if we can figure out a solution that does not involve the UI.

Regards,
Milan
the Telerik team

[Josh]

In this sample, if you right click on a cell in a grid a menu appears with the option to "Fill Right".  This copies the value of a cell to the cells on the right of it.  This sort of works but does not update the underlying ItemsSource and if you click on a cell where the value was changed, you will see it revert back to the old value which is not the intended behavior.

You may notice that I am filling the grid using a DataTable class I got from the link below.
DataTable blog

The reason I am using this DataTable is that the column names and number of columns will be unknown until runtime.  Unlike the sample project's static sample data, they are pulled from a database in which the number of "zones" and the name of each zone will change often.

I'm also open to a new approach if you could suggest one that might work.

-Josh

MainPage.xaml

<Grid x:Name="LayoutRoot" Background="White">
    <telerikGridView:RadGridView x:Name="gvZone" ItemsSource="{Binding TestSource}">
        <telerikNav:RadContextMenu.ContextMenu>
            <telerikNav:RadContextMenu Name="cMenu" Opened="cMenu_Opened"/>
        </telerikNav:RadContextMenu.ContextMenu>
    </telerikGridView:RadGridView>
</Grid>

MainPage.xaml.vb

Imports System.ComponentModel
Imports Telerik.Windows
Imports Telerik.Windows.Controls
Imports Telerik.Windows.Controls.GridView

Partial Public Class MainPage
    Inherits UserControl
    Implements INotifyPropertyChanged

    Public Event PropertyChanged(ByVal sender As Object, ByVal e As PropertyChangedEventArgs) Implements INotifyPropertyChanged.PropertyChanged

    Public Sub NotifyPropertyChanged(ByVal propertyName As String)
        RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(propertyName))
    End Sub

    Public Sub New()
        InitializeComponent()

        Me.DataContext = Me

        'Begin creating sample data
        Dim Zones As New List(Of Dictionary(Of String, Object))

        Dim Row1 As New Dictionary(Of String, Object)
        Row1.Add("Field Zone", 0.0024)
        Row1.Add("Zone 1A", 0.0079)
        Row1.Add("Zone 1B", 0.013)
        Row1.Add("Zone 2", 0.0141)
        Zones.Add(Row1)

        Dim Row2 As New Dictionary(Of String, Object)
        Row2.Add("Field Zone", 0.0079)
        Row2.Add("Zone 1A", 0.0055)
        Row2.Add("Zone 1B", 0.0106)
        Row2.Add("Zone 2", 0.0117)
        Zones.Add(Row2)

        Dim Row3 As New Dictionary(Of String, Object)
        Row3.Add("Field Zone", 0.013)
        Row3.Add("Zone 1A", 0.0106)
        Row3.Add("Zone 1B", 0.0051)
        Row3.Add("Zone 2", 0.0062)
        Zones.Add(Row3)

        Dim Row4 As New Dictionary(Of String, Object)
        Row4.Add("Field Zone", 0.0141)
        Row4.Add("Zone 1A", 0.0117)
        Row4.Add("Zone 1B", 0.0062)
        Row4.Add("Zone 2", 0.0011)
        Zones.Add(Row4)

        Dim dt As New SQLWiz.Data.DataTable(Zones)
        'End creation of sample data

        TestSource = dt
    End Sub

    Private _TestSource As SQLWiz.Data.DataTable
    Public Property TestSource() As SQLWiz.Data.DataTable
        Get
            Return _TestSource
        End Get
        Set(ByVal value As SQLWiz.Data.DataTable)
            _TestSource = value
            NotifyPropertyChanged("TestSource")
        End Set
    End Property

    Private Sub cMenu_Opened(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs)
        Dim ClickedGridCell As GridViewCell = cMenu.GetClickedElement(Of GridViewCell)()
        cMenu.Items.Clear()
        CreateMenu(ClickedGridCell)
    End Sub

    Private Sub CreateMenu(ByVal ClickedGridCell As GridViewCell)
        Dim mItem As RadMenuItem

        mItem = New RadMenuItem
        mItem.Header = "Fill Value Right"
        mItem.Tag = ClickedGridCell
        cMenu.Items.Add(mItem)
        AddHandler mItem.Click, AddressOf FillRight
    End Sub

    Sub FillRight(ByVal sender As Object, ByVal e As RadRoutedEventArgs)
        Dim mItem As RadMenuItem = sender
        Dim ClickedGridCell As GridViewCell = mItem.Tag
        Dim NewValue As String = ClickedGridCell.Value

        For Each cell As GridViewCell In ClickedGridCell.ParentRow.Cells
            If cell.Column.DisplayIndex > ClickedGridCell.Column.DisplayIndex Then
                cell.Value = NewValue
                cell.Content = NewValue

                'At this point cell.Value and cell.Content will be NewValue, however, the underlying datatable "TestSource" remains unchanged.
            End If
        Next
    End Sub
End Class

[Milan]

Hello Josh,

If you download the latest update of our DataTable which is available here you can programatically set value to the data rows (working with the data itself). For example:

Sub FillRight(ByVal sender As Object, ByVal e As RadRoutedEventArgs)
 {

    Dim mItem As RadMenuItem = sender
    Dim ClickedGridCell As GridViewCell = mItem.Tag
    Dim row As GridViewRow = ClickedGridCell.ParentRow

    Dim data as DynamicObject = row.DataContext

    '' Set new value for property Name
    data.SetValue("Name", "NewName");
 }

Kind regards,
Milan
the Telerik team

[Milan]

Hello Josh,

Forgot to paste the link. Here it is.

Greetings,
Milan
the Telerik team

[Josh]

That looks like it will work.  Thanks.

-Josh