System.Windows.Data Error: 8 : Cannot save value from target back to source. BindingExpression:Path=IsActive; DataItem='DistinctValueViewModel' (HashCode=49992105); target element is 'CheckBox' (Name=''); target property is 'IsChecked' (type 'Nullable`1') NullReferenceException:'System.NullReferenceException: Object reference not set to an instance of an object.
at Telerik.Windows.Controls.GridView.GridViewVirtualizingPanel.ArrangeOverride(Size finalSize) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Controls\GridView\GridView\GridView\Virtualization\GridViewVirtualizingPanel.cs:line 1517
at System.Windows.FrameworkElement.ArrangeCore(Rect finalRect)
at System.Windows.UIElement.Arrange(Rect finalRect)
at System.Windows.ContextLayoutManager.UpdateLayout()
at System.Windows.UIElement.UpdateLayout()
at Telerik.Windows.Controls.GridView.GridViewDataControl.ItemsSourceChanged(Boolean sourceChanged) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Controls\GridView\GridView\GridView\GridViewDataControl.cs:line 3157
at Telerik.Windows.Controls.GridView.GridViewDataControl.OnItemsChanged(NotifyCollectionChangedEventArgs e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Controls\GridView\GridView\GridView\GridViewDataControl.cs:line 8052
at Telerik.Windows.Controls.GridView.BaseItemsControl.OnItemCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Controls\GridView\GridView\GridView\ItemsControl\BaseItemsControl.cs:line 691
at System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
at Telerik.Windows.Data.DataItemCollection.OnCollectionChanged(NotifyCollectionChangedEventArgs e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\DataItemCollection.cs:line 653
at Telerik.Windows.Data.DataItemCollection.OnCollectionViewCollectionChanged(NotifyCollectionChangedEventArgs e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\DataItemCollection.cs:line 641
at Telerik.Windows.Data.DataItemCollection.Telerik.Windows.Data.IWeakEventListener<System.Collections.Specialized.NotifyCollectionChangedEventArgs>.ReceiveWeakEvent(Object sender, NotifyCollectionChangedEventArgs e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\DataItemCollection.cs:line 1034
at Telerik.Windows.Data.WeakEvent.WeakListener`1.Handler(Object sender, TArgs args) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\WeakEvents\WeakEvent.cs:line 32
at Telerik.Windows.Data.QueryableCollectionView.OnCollectionChanged(NotifyCollectionChangedEventArgs args) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\QueryableCollectionView.cs:line 669
at Telerik.Windows.Data.QueryableCollectionView.RefreshOverride() in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\QueryableCollectionView.cs:line 818
at Telerik.Windows.Data.QueryableCollectionView.RefreshInternal() in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\QueryableCollectionView.cs:line 765
at Telerik.Windows.Data.QueryableCollectionView.RefreshOrDefer() in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\QueryableCollectionView.cs:line 759
at Telerik.Windows.Data.QueryableCollectionView.InvalidatePagingAndRefresh() in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\QueryableCollectionView.cs:line 384
at Telerik.Windows.Data.QueryableCollectionView.OnFilterDescriptorsCollectionChanged(Object sender, NotifyCollectionChangedEventArgs e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\QueryableCollectionView.cs:line 419
at System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
at Telerik.Windows.Data.RadObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\RadObservableCollection.cs:line 143
at Telerik.Windows.Data.ObservableItemCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\ObservableItemCollection.cs:line 91
at System.Collections.ObjectModel.ObservableCollection`1.InsertItem(Int32 index, T item)
at Telerik.Windows.Data.RadObservableCollection`1.InsertItem(Int32 index, T item) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\RadObservableCollection.cs:line 189
at System.Collections.ObjectModel.Collection`1.Insert(Int32 index, T item)
at System.Collections.ObjectModel.Collection`1.System.Collections.IList.Insert(Int32 index, Object value)
at Telerik.Windows.Data.CollectionHelper.Insert(IList target, IEnumerable newItems, Int32 startingIndex, IEqualityComparer itemComparer) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\CollectionHelper.cs:line 334
at Telerik.Windows.Data.ObservableCollectionManager.HandleCollectionChanged(IList sender, NotifyCollectionChangedEventArgs args) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\Synchronization\ObservableCollectionManager.cs:line 105
at Telerik.Windows.Data.ObservableCollectionManager.Telerik.Windows.Data.IWeakEventListener<System.Collections.Specialized.NotifyCollectionChangedEventArgs>.ReceiveWeakEvent(Object sender, NotifyCollectionChangedEventArgs args) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\Synchronization\ObservableCollectionManager.cs:line 86
at Telerik.Windows.Data.WeakEvent.WeakListener`1.Handler(Object sender, TArgs args) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\WeakEvents\WeakEvent.cs:line 32
at System.Collections.Specialized.NotifyCollectionChangedEventHandler.Invoke(Object sender, NotifyCollectionChangedEventArgs e)
at System.Collections.ObjectModel.ObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e)
at Telerik.Windows.Data.RadObservableCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\RadObservableCollection.cs:line 143
at Telerik.Windows.Data.ObservableItemCollection`1.OnCollectionChanged(NotifyCollectionChangedEventArgs e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\ObservableItemCollection.cs:line 91
at System.Collections.ObjectModel.ObservableCollection`1.InsertItem(Int32 index, T item)
at Telerik.Windows.Data.RadObservableCollection`1.InsertItem(Int32 index, T item) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\RadObservableCollection.cs:line 189
at System.Collections.ObjectModel.Collection`1.Add(T item)
at Telerik.Windows.Controls.GridView.FilteringViewModel.OnPropertyChanged(Object sender, PropertyChangedEventArgs e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Controls\GridView\GridView\GridView\Filtering\FilteringViewModel.cs:line 541
at System.ComponentModel.PropertyChangedEventHandler.Invoke(Object sender, PropertyChangedEventArgs e)
at Telerik.Windows.Controls.ViewModelBase.OnPropertyChanged(String propertyName) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Controls\Common\ViewModelBase.cs:line 56
at Telerik.Windows.Controls.GridView.FilteringViewModel.Activate(IFilterDescriptor filter) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Controls\GridView\GridView\GridView\Filtering\FilteringViewModel.cs:line 589
at Telerik.Windows.Controls.GridView.FilteringViewModel.OnDistinctValuesItemChanged(Object sender, ItemChangedEventArgs`1 e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Controls\GridView\GridView\GridView\Filtering\FilteringViewModel.cs:line 558
at Telerik.Windows.Data.ObservableItemCollection`1.RaiseGenericItemChanged(ItemChangedEventArgs`1 e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\ObservableItemCollection.cs:line 69
at Telerik.Windows.Data.ObservableItemCollection`1.OnItemChanged(ItemChangedEventArgs`1 e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\ObservableItemCollection.cs:line 51
at Telerik.Windows.Data.ObservableItemCollection`1.OnItemPropertyChanged(Object sender, PropertyChangedEventArgs e) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Data\Collections\ObservableItemCollection.cs:line 110
at System.ComponentModel.PropertyChangedEventHandler.Invoke(Object sender, PropertyChangedEventArgs e)
at Telerik.Windows.Controls.ViewModelBase.OnPropertyChanged(String propertyName) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Core\Controls\Common\ViewModelBase.cs:line 56
at Telerik.Windows.Controls.GridView.DistinctValueViewModel.set_IsActive(Boolean value) in c:\Builds\WPF_Scrum\Release_WPF\Sources\Development\Controls\GridView\GridView\GridView\Filtering\DistinctValueViewModel.cs:line 27'
Private
Sub GetControlNames(ByVal oControl As Object)
Try
If IsNothing(oControl) Then GoTo lable1
Dim child As Object
If sSelectedControl = child.GetType.Name Then
cmbControlsName.Items.Add(child.Name)
End If
GetControlNames(child)
Catch ex As Exception
ShowMessage(ex.Message)
End Try
End Sub
Note: I have the above said two ComboBoxes and a Frame in one Page and the Frame will load another page namely Page1 in it. The content of the Frame will be passed as the argument for the above function.
Here, I have used the Recursive function(well you know). When the RadGridView is passed as the argument of the function, it jumps to the label "lable1" from "For Each" statement. So, it means the RadGridView doesn't have children. Then, how can I get the MenuItem I've used under RadGridView. Please let me know the solution.
Thanks and Regards,
Azharshah H
Software Developer
public
class
AppointmentTaskVm : Appointment
{
private
int
_appointmentTaskId;
private
bool
_isBasketItem;
private
int
_position;
private
int
? _taskId;
public
int
AppointmentTaskId
{
get
{
return
_appointmentTaskId; }
set
{
_appointmentTaskId = value;
OnPropertyChanged(
"AppointmentTaskId"
);
}
}
public
bool
IsBasketItem
{
get
{
return
_isBasketItem; }
set
{
_isBasketItem = value;
OnPropertyChanged(
"IsBasketItem"
);
}
}
public
int
Position
{
get
{
return
_position; }
set
{
_position = value;
OnPropertyChanged(
"Position"
);
}
}
public
int
? TaskId
{
get
{
return
_taskId; }
set
{
_taskId = value;
OnPropertyChanged(
"TaskId"
);
}
}
public
override
IAppointment Copy()
{
var newAppointment =
new
AppointmentTaskVm();
newAppointment.CopyFrom(
this
);
return
newAppointment;
}
public
override
void
CopyFrom(IAppointment other)
{
var task = other
as
AppointmentTaskVm;
if
(task !=
null
)
{
AppointmentTaskId = task.AppointmentTaskId;
IsBasketItem = task.IsBasketItem;
Position = task.Position;
TaskId = task.TaskId;
}
base
.CopyFrom(other);
}
}
Hi,
I am trying to select values from a bounded combobox inside a GridView.
But after a select it and try to select other the previous selected value is not visible.
below is code in xaml :-
<telerik:RadGridView Margin="5,0,0,0" Grid.Row="4" Grid.ColumnSpan="2" Name="gvGISMapFields" Width="610" ShowColumnHeaders="True" ShowGroupPanel="False" Height="250">
<telerik:RadGridView.Columns>
<telerik:GridViewComboBoxColumn Name="MatchingField" DisplayMemberPath="MatchingField" UniqueName="MatchingField" HeaderText="Target Field" IsFilterable="False" IsGroupable="False" IsReorderable="False" IsSortable="False" TextAlignment="Center" Width="250"/>
</telerik:RadGridView.Columns>
</telerik:RadGridView>
below is code in xaml.cs :-
GridViewComboBoxColumn matchingField = (GridViewComboBoxColumn)gvMapFields.Columns[1];
matchingField.ItemsSource = matchingGISFields;
<
telerik:RadComboBox
ItemsSource
=
"{Binding}"
DisplayMemberPath
=
"Name"
x:Name
=
"cboCurrencyList"
/>
Source="{Binding ElementName=cboCurrencyList, Path=SelectedValue}"/>
public
class
CalendarButtonTemplateSelector : DataTemplateSelector
{
public
override
DataTemplate SelectTemplate(
object
item, DependencyObject container)
{
CalendarButtonContent content = item
as
CalendarButtonContent;
if
(content !=
null
&& content.ButtonType == CalendarButtonType.Date)
{
if
(CentralCalendarWindow.CalendarViewItems !=
null
&& CentralCalendarWindow.CalendarViewItems.Exists(c => c.Date == content.Date))
{
CalendarViewItem calendarViewItem = CentralCalendarWindow.CalendarViewItems.Find(c => c.Date == content.Date);
if
(calendarViewItem.IsHoliday)
{
return
HolidayTemplate;
}
}
}
}
}
<
DataTemplate
>
<
StackPanel
>
<
TextBlock
Text
=
"{Binding Text}"
/>
<
TextBlock
Text
=
"{Binding CustomText}"
/>
</
StackPanel
>
</
DataTemplate
>