Performance Issue with ListControl and Observable Dictionary WPF - wpf

Question

I have an itemsControl bound to an observable dictionary, showing both the Key and Value in two textboxes,
It takes about 15 seconds for the usercontrol to load.
I tried virtualizing stackpanels and switching it to either a listbox or using a regular dictionary, and the lag still occurs
Any ideas what might be causing this, and how I can get it to load faster?
public partial class WordsView : UserControl, INotifyPropertyChanged
{
public WordsView()
{
InitializeComponent();
Dictionarylist.ItemsSource = curDic;
}
private ObservableDictionary<string,int> cur_dic = new ObservableDictionary<string, int>(App.PredDic);
public ObservableDictionary<string, int> curDic
{
get { return cur_dic; }
set
{
SetField(ref cur_dic, value, "curDic");
}
}
}
}
and my xaml
<UserControl x:Class="Ez.Management.WordsView"
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:local="clr-namespace:Ez.Management"
DataContext="{Binding RelativeSource={RelativeSource Self}}"
xmlns:properties="clr-namespace:Ez.Properties"
xmlns:main ="clr-namespace:Ez"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<StackPanel>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<GroupBox Grid.Row="1" Header="Words">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="Auto"/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<ItemsControl x:Name="Dictionarylist" ItemsSource="{Binding curDic}" VirtualizingStackPanel.IsVirtualizing="True"
ScrollViewer.CanContentScroll="True">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<VirtualizingStackPanel></VirtualizingStackPanel>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemTemplate>
<DataTemplate>
<Grid Margin="3">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="3*"></ColumnDefinition>
<ColumnDefinition Width="1*"></ColumnDefinition>
</Grid.ColumnDefinitions>
<TextBlock Text="{Binding Key}" Grid.Column="0" />
<TextBlock Text="{Binding Value}" Grid.Column="1"/>
</Grid>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
</Grid>
</GroupBox>
</Grid>
</StackPanel>
</UserControl>

Answer 1

ScrollViewer.CanContentScroll is taking time... Try setting it to False. Like,
ScrollViewer.CanContentScroll="False"