SLOW LOADING WPF FORM.

Royce Roy

Total Post:149

Points:1043
Posted by  Royce Roy
WPF 
WPF
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Hi Guys

I've been search for a solution to a slow loading wpf form. It seems that virtualization should help me out, but I must be missing something.

I'm loading 35k orders and it takes 15 seconds to load. My guess is that virtualization isn't actually working for me.

<UserControl x:Class="IntTranWin.Modules.Orders.OrderSummary.OrdersSummaryView"

         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" mc:Ignorable="d" d:DesignHeight="300" d:DesignWidth="300">

  <ListView BorderThickness="0" Width="Auto" ItemsSource="{Binding Path=Orders.Items}" AlternationCount="2"

            IsSynchronizedWithCurrentItem="True" VirtualizingStackPanel.IsVirtualizing="True"

            VirtualizingStackPanel.VirtualizationMode="Recycling" ScrollViewer.IsDeferredScrollingEnabled="True">

    <ListView.ItemsPanel>

      <ItemsPanelTemplate>

        <VirtualizingStackPanel />

      </ItemsPanelTemplate>

    </ListView.ItemsPanel>

    <ListView.View>

      <GridView AllowsColumnReorder="true" ColumnHeaderToolTip="Orders">

        <GridViewColumn Header="Number" DisplayMemberBinding="{Binding Path=OrderNumber}" Width="65" />

      </GridView>

    </ListView.View>

  </ListView>

</UserControl>

Thanks 

  1. shreesh chandra shukla

    Post:105

    Points:735
    Re: Slow loading WPF Form.

    Hi!

    There wasn't really anything wrong with wpf I provided. The problem was in a styling of ScrollViewer for the GridView which disabled virtualization. 

    <Style x:Key="{x:Static GridView.GridViewScrollViewerStyleKey}" TargetType="{x:Type ScrollViewer}">

    <Setter Property="Template">

      <Setter.Value>

        <ControlTemplate TargetType="{x:Type ScrollViewer}">

          <Grid Background="{TemplateBinding Background}">

            <Grid.ColumnDefinitions>

              <ColumnDefinition Width="*" />

              <ColumnDefinition Width="Auto" />

            </Grid.ColumnDefinitions>

            <Grid.RowDefinitions>

              <RowDefinition Height="*" />

              <RowDefinition Height="Auto" />

            </Grid.RowDefinitions> 

            <DockPanel Margin="{TemplateBinding Padding}">

              <ScrollViewer DockPanel.Dock="Top" HorizontalScrollBarVisibility="Hidden" VerticalScrollBarVisibility="Hidden"

                            Focusable="false">

                <Border CornerRadius="4" Background="{StaticResource DefaultedBorderBrush}" Padding="4" Margin="0,4,0,4">

                  <GridViewHeaderRowPresenter Margin="2,0,2,0"

                                              Columns="{Binding Path=TemplatedParent.View.Columns,RelativeSource={RelativeSource TemplatedParent}}"

                                              ColumnHeaderContainerStyle="{Binding Path=TemplatedParent.View.ColumnHeaderContainerStyle,RelativeSource={RelativeSource TemplatedParent}}"

                                              ColumnHeaderTemplate="{Binding Path=TemplatedParent.View.ColumnHeaderTemplate,RelativeSource={RelativeSource TemplatedParent}}"

                                              ColumnHeaderTemplateSelector="{Binding Path=TemplatedParent.View.ColumnHeaderTemplateSelector,RelativeSource={RelativeSource TemplatedParent}}"

                                              AllowsColumnReorder="{Binding Path=TemplatedParent.View.AllowsColumnReorder,RelativeSource={RelativeSource TemplatedParent}}"

                                              ColumnHeaderContextMenu="{Binding Path=TemplatedParent.View.ColumnHeaderContextMenu,RelativeSource={RelativeSource TemplatedParent}}"

                                              ColumnHeaderToolTip="{Binding Path=TemplatedParent.View.ColumnHeaderToolTip,RelativeSource={RelativeSource TemplatedParent}}"

                                              SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />

                </Border> 

              </ScrollViewer> 

              <ScrollContentPresenter Name="PART_ScrollContentPresenter" KeyboardNavigation.DirectionalNavigation="Local" />

            </DockPanel> 

            <ScrollBar Name="PART_HorizontalScrollBar" Orientation="Horizontal" Grid.Row="1"

                       Maximum="{TemplateBinding ScrollableWidth}" ViewportSize="{TemplateBinding ViewportWidth}"

                       Value="{TemplateBinding HorizontalOffset}" Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}" /> 

            <ScrollBar Name="PART_VerticalScrollBar" Grid.Column="1" Maximum="{TemplateBinding ScrollableHeight}"

                       ViewportSize="{TemplateBinding ViewportHeight}" Value="{TemplateBinding VerticalOffset}"

                       Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" /> 

          </Grid>

        </ControlTemplate>

      </Setter.Value>

    </Setter> 

    I hope it will work fine.

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