Questions on UI for WPF Forum

2 answers

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Hello,
Sorry for the bad title. I could not guess what kind of an problem it was.
Bellow is our .xaml and .cs codes. After adding an amount of values to the grid, the grid throws an exception. I gave all of the code at the page because there was another thread about this subject and "telerik" had requested to code.
Generally it gives the error after 20-30 records added to the grid.

The computer specs where the application is used:
1. Ultra mobile pc
2. Atom processor
3. Windows 7 with .net framework 3.5

we are using 2010.1.603.35 version of telerik.

<base:PageBase x:Class="Shop.App.WPF.Pages.Secured.CycleCount.PageCycleCount"

xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

xmlns:base="clr-namespace:Shop.App.WPF.Pages.Base"

xmlns:Telerik="http://schemas.telerik.com/2008/xaml/presentation"

mc:Ignorable="d"

d:DesignHeight="600" d:DesignWidth="900"

Title="Sayım">

<Grid DataContext=

"{Binding RelativeSource={RelativeSource AncestorType={x:Type base:PageBase}, Mode=FindAncestor}, Path=CycleCountService}"

>

<Grid.RowDefinitions>

<RowDefinition Height="Auto"></RowDefinition>

<RowDefinition Height="*"></RowDefinition>

</Grid.RowDefinitions>

<StackPanel Grid.Row="0" Orientation="Horizontal" >

<TextBlock Margin="5" Style="{StaticResource StyleTextBlock}" VerticalAlignment="Center" Text="Depo"></TextBlock>

<ComboBox Name="ComboBoxWarehouse" MinWidth="150" Margin="5" ItemsSource=

"{Binding RelativeSource={RelativeSource AncestorType={x:Type base:PageBase}, Mode=FindAncestor}, Path=WarehouseContext.Values}"

SelectedIndex="0" DisplayMemberPath="Name" SelectionChanged="ComboBoxWarehouse_SelectionChanged"></ComboBox>

</StackPanel>

<StackPanel Grid.Row="1" Orientation="Horizontal">

<TextBlock Style="{StaticResource StyleTextBlock}" Text="Stok Kodu" Margin="5" VerticalAlignment="Center"></TextBlock>

<TextBox Margin="5" VerticalAlignment="Center" Name="TextBoxItemStockCode" Width="200" KeyDown="TextBoxItemStockCode_KeyDown"></TextBox>

<TextBlock Style="{StaticResource StyleTextBlock}" Text="Adet" Margin="5" VerticalAlignment="Center"></TextBlock>

<Telerik:RadNumericUpDown Margin="5" Minimum="1" IsInteger="True" x:Name="NumericPieces"></Telerik:RadNumericUpDown>

<TextBlock Text="{Binding Path=ProductDataContext.Value.ItemName}" Margin="5" VerticalAlignment="Center" Name="TextBlockItemName" Width="Auto" TextWrapping="Wrap"></TextBlock>

</StackPanel>

<Telerik:RadGridView

Margin="5"

Grid.Row="2"

x:Name="GridItems"

AutoGenerateColumns="False"

ItemsSource="{Binding Path=CycleCountItemContext.Values}"

>

<Telerik:RadGridView.Columns>

<Telerik:GridViewDataColumn Header="Stok Kodu" DataMemberBinding="{Binding Path=ItemStockCode}"></Telerik:GridViewDataColumn>

<Telerik:GridViewDataColumn Header="Stok Adı" DataMemberBinding="{Binding Path=ItemName}"></Telerik:GridViewDataColumn>

<Telerik:GridViewDataColumn Header="Stok Bakiye" DataMemberBinding="{Binding Path=StartCount}"></Telerik:GridViewDataColumn>

<Telerik:GridViewDataColumn Header="Satılan Miktar" DataMemberBinding="{Binding Path=SoldCount}"></Telerik:GridViewDataColumn>

<Telerik:GridViewDataColumn Header="Sayılan" DataMemberBinding="{Binding Path=Counted}"></Telerik:GridViewDataColumn>

<Telerik:GridViewDataColumn Header="Son Bakiye" DataMemberBinding="{Binding Path=EndCount}"></Telerik:GridViewDataColumn>

<Telerik:GridViewDataColumn Header="Kategori" DataMemberBinding="{Binding Path=Product.Category.Name}"></Telerik:GridViewDataColumn>

</Telerik:RadGridView.Columns>

</Telerik:RadGridView>

</Grid>

</base:PageBase>

namespace Shop.App.WPF.Pages.Secured.CycleCount

{

/// <summary>

/// Interaction logic for PageCycleCount.xaml

/// </summary>

public partial class PageCycleCount : PageBase, INotifyPropertyChanged

{

private WarehouseContext _WarehouseContext;

public WarehouseContext WarehouseContext

{

get { return _WarehouseContext; }

set

{

_WarehouseContext = value;

PropertyChanged(this, new PropertyChangedEventArgs("WarehouseContext"));

}

private CycleCountService _CycleCountService = null;

public CycleCountService CycleCountService

{

get

{

return _CycleCountService;

}

set

{

_CycleCountService = new CycleCountService();

PropertyChanged(this, new PropertyChangedEventArgs("CycleCountService"));

}

public PageCycleCount()

{

PropertyChanged += new PropertyChangedEventHandler(PageCreateNew_PropertyChanged);

CycleCountService = new Business.Services.CycleCountService();

WarehouseContext = new Business.Contexts.WarehouseContext();

InitializeComponent();

WarehouseContext.LoadAll();

CycleCountService.LoadActiveCountItems(WarehouseContext.Values.FirstOrDefault().ID);

}

void PageCreateNew_PropertyChanged(object sender, PropertyChangedEventArgs e)

{

}

#region INotifyPropertyChanged Members

public event PropertyChangedEventHandler PropertyChanged;

#endregion

private void TextBoxItemStockCode_KeyDown(object sender, KeyEventArgs e)

{

CycleCountItem item = null;

try

{

if (e.Key == Key.Enter)

{

item = CycleCountService.AddCount(

(ComboBoxWarehouse.SelectedItem as Warehouse).ID,

TextBoxItemStockCode.Text,

Convert.ToInt32(NumericPieces.Value));

NumericPieces.Value = 1;

GridItems.ScrollIntoView(item);

GridItems.SelectedItem = item;

TextBoxItemStockCode.Text = "";

CycleCountService.LoadActiveCountItems((ComboBoxWarehouse.SelectedItem as Warehouse).ID);

}

catch (UserException exc)

{

SendErrorMessage(exc.Message);

}

catch (Exception exc)

{

CommonExceptionAction(exc);

}

private void ComboBoxWarehouse_SelectionChanged(object sender, SelectionChangedEventArgs e)

{

try

{

CycleCountService.LoadActiveCountItems((ComboBoxWarehouse.SelectedItem as Warehouse).ID);

}

catch (UserException exc)

{

SendErrorMessage(exc.Message);

}

catch (Exception exc)

{

CommonExceptionAction(exc);

}

The Error :

PresentationHost.exe Error: 0 : System.NullReferenceException:

target: Telerik.Windows.Controls.GridView.GridViewItemContainerGenerator.Remove(GeneratorPosition position, Int32 count, Boolean isRecycling)

target: Telerik.Windows.Controls.GridView.GridViewItemContainerGenerator.System.Windows.Controls.Primitives.IRecyclingItemContainerGenerator.Recycle(GeneratorPosition position, Int32 count)

target: Telerik.Windows.Controls.GridView.GridViewVirtualizingPanel.CleanupRange(IList children, IItemContainerGenerator generator, Int32 startIndex, Int32 count)

target: Telerik.Windows.Controls.GridView.GridViewVirtualizingPanel.CleanupContainers(Int32 firstViewport, BaseItemsControl itemsControl)

target: Telerik.Windows.Controls.GridView.GridViewVirtualizingPanel.MeasureOverride(Size constraint)

target: System.Windows.FrameworkElement.MeasureCore(Size availableSize)