スクロール中にテンプレートが適用されない

Question

私はスクロールビューアでグリッドを使用しています。そのグリッドは、UI要素の数を増やして設計しました。そのレポートを開くと、パフォーマンスの問題で最初のページのUI要素のみがレンダリングされました。スクロール中に残りのUI要素をレンダリングする必要があります。

スクロールスクロールビューアテンプレートが残りの要素の秒間印加されていませんが私の質問は、

です。 しかし、最初のページのUI要素はテンプレートで正しく更新されます。

なぜスクロールを実行するのですか？テンプレートは1秒間適用されません。

XAMLファイルのコードスニペット：背後

 <ScrollViewer Grid.Row="1" Focusable="False" ScrollChanged="DesignScrollViewer_ScrollChanged" x:Name="DesignScrollViewer" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Auto"> 
      <ScrollViewer.Template> 
       <ControlTemplate TargetType="{x:Type ScrollViewer}"> 
        <Grid x:Name="Grid" Background="#FFF9F9F9"> 
         <Grid.ColumnDefinitions> 
          <ColumnDefinition Width="*" /> 
         </Grid.ColumnDefinitions> 
         <Grid.RowDefinitions> 
          <RowDefinition Height="*" /> 
          <RowDefinition Height="0" /> 
         </Grid.RowDefinitions> 
         <Grid AllowDrop="True" Grid.Column="0" Grid.Row="1"> 
          <Grid.ColumnDefinitions> 
           <ColumnDefinition Width="*" /> 
          </Grid.ColumnDefinitions> 

          <Border Background="#ffffffff" BorderBrush="#ffbbbbbb" Visibility="Collapsed" BorderThickness="0,1,1,0" Grid.Column="1"> 
           <StackPanel Orientation="Horizontal"> 
            <ToggleButton Width="16" ToolTip="Layout" x:Name="AutoFit" Grid.Column="0" Style="{StaticResource ToggleButtonStyle}" Click="AutoFit_Click_1" VerticalAlignment="Stretch" Margin="0" Height="12"> 
             <Path x:Name="fittoscreen" Data="M8.84896,6.54523 L10.66668,6.54523 10.66668,10.666019 6.5462299,10.666019 6.5462299,8.847971 8.84896,8.847971 z M0,6.54523 L1.8183599,6.54523 1.8183599,8.8479717 4.12177,8.8479717 4.12177,10.66602 0,10.66602 z M6.5462299,0 L10.66668,0 10.66668,4.1210899 8.84896,4.1210899 8.84896,1.8183599 6.5462299,1.8183599 z M0,0 L4.12177,0 4.12177,1.8183599 1.8183601,1.8183599 1.8183601,4.1210899 0,4.1210899 z" Fill="#FF646464" Height="8" Stretch="Fill" Width="8" /> 
            </ToggleButton> 
            <ComboBox Margin="0" ItemContainerStyle="{StaticResource ZoomComboboxItem}" AllowDrop="True" SelectedIndex="-1" Style="{StaticResource ZoomComboBoxStyle}" IsEditable="True" VerticalAlignment="Stretch" Height="12" FontSize="10" Tag="AtStart" PreviewKeyDown="cmboSearchField_PreviewKeyDown" BorderThickness="0" x:Name="cmboSearchField" Width="50" KeyDown="cmboSearchField_KeyDown_1" SelectionChanged="cmboSearchField_SelectionChanged_1" IsTextSearchEnabled="false" /> 

             <ComboBoxItem FontSize="10" x:Name="Item1" Content="20 %" /> 
             <ComboBoxItem FontSize="10" x:Name="Item2" Content="50 %" /> 
             <ComboBoxItem FontSize="10" x:Name="Item3" Content="70 %" /> 
             <ComboBoxItem FontSize="10" x:Name="Item4" Content="100 %" /> 
             <ComboBoxItem FontSize="10" x:Name="Item5" Content="150 %" /> 
             <ComboBoxItem FontSize="10" x:Name="Item6" Content="200 %" /> 
             <ComboBoxItem FontSize="10" x:Name="Item7" Content="400 %" /> 
            </ComboBox> 
           </StackPanel> 
          </Border> 

          <Border Background="#FFFFFFFF" VerticalAlignment="Bottom" BorderBrush="#FFBBBBBB" Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}" BorderThickness="0,1,1,0" Grid.Column="0"> 
           <ScrollBar HorizontalAlignment="Stretch" BorderThickness="0" AllowDrop="True" x:Name="PART_HorizontalScrollBar" AutomationProperties.AutomationId="HorizontalScrollBar" Cursor="Arrow" Maximum="{TemplateBinding ScrollableWidth}" Minimum="0" Orientation="Horizontal" Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}" Value="{Binding HorizontalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" ViewportSize="{TemplateBinding ViewportWidth}" Margin="0,-1" Height="16" /> 
          </Border> 
         </Grid> 
         <!--<Rectangle x:Name="Corner" Grid.Column="" Fill="Transparent" Grid.Row="1" />--> 
         <ScrollContentPresenter x:Name="PART_ScrollContentPresenter" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" CanContentScroll="{TemplateBinding CanContentScroll}" CanHorizontallyScroll="False" CanVerticallyScroll="False" ContentTemplate="{TemplateBinding ContentTemplate}" Content="{TemplateBinding Content}" Grid.Column="0" Grid.Row="0"/> 
         <Border x:Name="ContentScroll" BorderThickness="0" Background="#FFF9F9F9" HorizontalAlignment="Right" Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" BorderBrush="#FFBBBBBB" Grid.Column="1"> 
          <ScrollBar HorizontalAlignment="Right" HorizontalContentAlignment="Center" x:Name="PART_VerticalScrollBar" AutomationProperties.AutomationId="VerticalScrollBar" Cursor="Arrow" Grid.Column="1" Maximum="{TemplateBinding ScrollableHeight}" Minimum="0" Grid.Row="0" Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" Value="{Binding VerticalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" ViewportSize="{TemplateBinding ViewportHeight}" /> 
         </Border> 
        </Grid> 
       </ControlTemplate> 
      </ScrollViewer.Template> 
      <Grid Focusable="False" VerticalAlignment="Center" HorizontalAlignment="Center"> 
       <!--<Grid.RowDefinitions> 
       <RowDefinition x:Name="FilterZoneRow" Height="Auto" /> 
       <RowDefinition Height="Auto" /> 
       <RowDefinition Height="Auto" /> 
      </Grid.RowDefinitions>--> 
       <!--<Grid x:Name="FilterZone" Margin="0,0,0,5" Background="#FF1A1A1A" Visibility="Collapsed"> 
       <Grid x:Name="FilterGrid"> 
        <designLayout:GridCanvas x:Name="FZoneCanvas" KeyboardNavigation.IsTabStop="False" RowCount="0" IsInDesignMode="True" CanvasLayout="DesktopFreeForm" FreeFormSize="Small" Transform="{Binding ElementName=Canvas,Path=Transform,Mode=TwoWay}" ShowGridLines="{Binding Path=ShowGridLines,ElementName=Canvas}" Background="#FF1A1A1A"> 
        </designLayout:GridCanvas> 
        <Canvas> 
         <Border x:Name="FilterControlPlacementBorder" Visibility="Collapsed" BorderBrush="Red" BorderThickness="1"> 
         </Border> 
         <Button x:Name="FilterControlPlacementContent" KeyboardNavigation.IsTabStop="False" Visibility="Collapsed" IsHitTestVisible="False" BorderBrush="{x:Null}" VerticalAlignment="Center" HorizontalAlignment="Center" /> 
         <Rectangle StrokeDashArray="4 2" x:Name="SelectionFRect" Visibility="Collapsed" Stroke="Gray" StrokeThickness="1.5" /> 
        </Canvas> 
       </Grid> 
       <Border x:Name="FilterZoneBorder" BorderBrush="Yellow" AllowDrop="False" Visibility="Collapsed" BorderThickness="1" /> 
      </Grid>--> 
       <Grid Grid.Row="0" Focusable="True" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" FocusVisualStyle="{x:Null}" x:Name="CanvasGrid"> 
        <Border BorderBrush="Transparent" BorderThickness="0" Background="Transparent"> 
         <Border.Effect> 
          <DropShadowEffect ShadowDepth="0" BlurRadius="5" Opacity="0.3" Color="Black" /> 
         </Border.Effect> 
        </Border> 

         <designLayout:GridCanvas KeyboardNavigation.IsTabStop="True" KeyboardNavigation.TabNavigation="Once" FocusVisualStyle="{x:Null}" Background="Transparent" x:Name="Canvas" CanvasLayout="DesktopGridCanvas" VerticalAlignment="Center" HorizontalAlignment="Center" ClipToBounds="True" Focusable="True" ShowGridLines="True" IsInDesignMode="True"> 
         </designLayout:GridCanvas> 

        <Canvas> 
         <Border x:Name="ControlPlacementBorder" Visibility="Collapsed" BorderThickness="1"> 
          <!--<Button x:Name="ControlPlacementContent" IsHitTestVisible="False" BorderBrush="{x:Null}" VerticalAlignment="Center" HorizontalAlignment="Center" />--> 
         </Border> 
        </Canvas> 
       </Grid> 
      </Grid> 
     </ScrollViewer> 

コード：事前に

private void DesignScrollViewer_ScrollChanged(object sender, ScrollChangedEventArgs e) 
    { 
     if (e.VerticalOffset > OffsetValue) 
     { 
      OffsetValue = e.VerticalOffset; 
      if (TempCanvasRowCount < DesignCanvas.RowCount &&(e.VerticalOffset/48) > prevCanvasRowCount) 
      { 
       TempCanvasRowCount += 12; 
       prevCanvasRowCount += 12; 
       RenderingElements(); 
       if (TempCanvasRowCount > DesignCanvas.RowCount) 
        TempCanvasRowCount = DesignCanvas.RowCount; 
      } 
     } 
    } 

感謝。

Answer 1

最後に、

私は、テンプレートの解決策が仮想スクロール中に適用されないことを発見しました。

レンダリングウィジェットのコードをバックグラウンドワーカーとして実行すると、これが解決されます。

private void DesignScrollViewer_ScrollChanged(object sender, ScrollChangedEventArgs e) 
{ 
    if (e.VerticalOffset > OffsetValue) 
    { 
    OffsetValue = e.VerticalOffset; 
    if (TempCanvasRowCount < DesignCanvas.RowCount && (e.VerticalOffset/48) > prevCanvasRowCount) 
     { 
     TempCanvasRowCount += 12; 
     prevCanvasRowCount += 12; 
     var _backGroundWorker = new BackgroundWorker { } 
     _backGroundWorker.DoWork += (obj, args) => 
     { 
      RenderingWidgets(window.DashboardDesigner); 
      }; 
     _backGroundWorker.RunWorkerCompleted += (obj, args) => 
     { 
      if (TempCanvasRowCount > DesignCanvas.RowCount) 
       TempCanvasRowCount = DesignCanvas.RowCount; 
      }; 
       _backGroundWorker.RunWorkerAsync(this);    
     } 
    }   
}