在WPF中更新GridView时如何禁用滚动条更改

Question

I have a problem regarding to Gridview update. I am using ObservableCollection to bind the data and whenever ObservableCollection is updated the grid is updated as well. However, the scrollbar goes to the top at each update. For example, I am dealing (reading the details about a selected row, updating the row, etc..) with a row and at the same time more data is added to Grid continuously. At each update UI is also updated and scrollbar goes to the top. This interrupts my work with the selected row.

I also don't want to save the current row and focus UI to this row again after each update because that also interrupts my process with the selected row and freezes it. I basically do not want an update on the current available rows of my Grid. When new data comes, it should be added to the end of my grid and this process should not interrupt my work with the previous rows. Thanks for any kind of help.

Answer 1

You can access the DataGrid's internal ScrollViewer by modifying the template. Although normally you wouldn't put an event handler to code behind in a template, if you declare the template inline you can treat the event handler the same way you are when you attach it to the DataGrid itself. This is the default template as generated from Blend including an added handler on the ScrollViewer for the RequestBringIntoView event:

<ControlTemplate TargetType="{x:Type Controls:DataGrid}">
<Border SnapsToDevicePixels="True" Background="{TemplateBinding Background}" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Padding="{TemplateBinding Padding}">
    <ScrollViewer x:Name="DG_ScrollViewer" Focusable="False" RequestBringIntoView="DG_ScrollViewer_RequestBringIntoView">
        <ScrollViewer.Template>
            <ControlTemplate TargetType="{x:Type ScrollViewer}">
                <Grid>
                    <Grid.RowDefinitions>
                        <RowDefinition Height="Auto"/>
                        <RowDefinition Height="*"/>
                        <RowDefinition Height="Auto"/>
                    </Grid.RowDefinitions>
                    <Grid.ColumnDefinitions>
                        <ColumnDefinition Width="Auto"/>
                        <ColumnDefinition Width="*"/>
                        <ColumnDefinition Width="Auto"/>
                    </Grid.ColumnDefinitions>
                    <Button Width="{Binding CellsPanelHorizontalOffset, RelativeSource={RelativeSource FindAncestor, AncestorLevel=1, AncestorType={x:Type Controls:DataGrid}}}" Focusable="False">
                        <Button.Visibility>
                            <Binding Path="HeadersVisibility" RelativeSource="{RelativeSource FindAncestor, AncestorLevel=1, AncestorType={x:Type Controls:DataGrid}}">
                                <Binding.ConverterParameter>
                                    <Controls:DataGridHeadersVisibility>All</Controls:DataGridHeadersVisibility>
                                </Binding.ConverterParameter>
                            </Binding>
                        </Button.Visibility>
                        <Button.Template>
                            <ControlTemplate TargetType="{x:Type Button}">
                                <Grid>
                                    <Rectangle x:Name="Border" Fill="{DynamicResource {x:Static SystemColors.ControlBrushKey}}" SnapsToDevicePixels="True"/>
                                    <Polygon x:Name="Arrow" Fill="Black" Stretch="Uniform" HorizontalAlignment="Right" Margin="8,8,3,3" VerticalAlignment="Bottom" Opacity="0.15" Points="0,10 10,10 10,0"/>
                                </Grid>
                                <ControlTemplate.Triggers>
                                    <Trigger Property="IsMouseOver" Value="True">
                                        <Setter Property="Stroke" TargetName="Border" Value="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}"/>
                                    </Trigger>
                                    <Trigger Property="IsPressed" Value="True">
                                        <Setter Property="Fill" TargetName="Border" Value="{DynamicResource {x:Static SystemColors.ControlDarkBrushKey}}"/>
                                    </Trigger>
                                    <Trigger Property="IsEnabled" Value="False">
                                        <Setter Property="Visibility" TargetName="Arrow" Value="Collapsed"/>
                                    </Trigger>
                                </ControlTemplate.Triggers>
                            </ControlTemplate>
                        </Button.Template>
                        <Button.Command>
                            <RoutedCommand/>
                        </Button.Command>
                    </Button>
                    <Custom:DataGridColumnHeadersPresenter x:Name="PART_ColumnHeadersPresenter" Grid.Column="1">
                        <Custom:DataGridColumnHeadersPresenter.Visibility>
                            <Binding Path="HeadersVisibility" RelativeSource="{RelativeSource FindAncestor, AncestorLevel=1, AncestorType={x:Type Controls:DataGrid}}">
                                <Binding.ConverterParameter>
                                    <Controls:DataGridHeadersVisibility>Column</Controls:DataGridHeadersVisibility>
                                </Binding.ConverterParameter>
                            </Binding>
                        </Custom:DataGridColumnHeadersPresenter.Visibility>
                    </Custom:DataGridColumnHeadersPresenter>
                    <ScrollContentPresenter x:Name="PART_ScrollContentPresenter" Grid.ColumnSpan="2" Grid.Row="1" Content="{TemplateBinding Content}" ContentStringFormat="{TemplateBinding ContentStringFormat}" ContentTemplate="{TemplateBinding ContentTemplate}" CanContentScroll="{TemplateBinding CanContentScroll}" CanHorizontallyScroll="False" CanVerticallyScroll="False"/>
                    <ScrollBar x:Name="PART_VerticalScrollBar" Visibility="{TemplateBinding ComputedVerticalScrollBarVisibility}" Grid.Column="2" Grid.Row="1" Maximum="{TemplateBinding ScrollableHeight}" Value="{Binding VerticalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" Orientation="Vertical" ViewportSize="{TemplateBinding ViewportHeight}"/>
                    <Grid Grid.Column="1" Grid.Row="2">
                        <Grid.ColumnDefinitions>
                            <ColumnDefinition Width="{Binding NonFrozenColumnsViewportHorizontalOffset, RelativeSource={RelativeSource FindAncestor, AncestorLevel=1, AncestorType={x:Type Controls:DataGrid}}}"/>
                            <ColumnDefinition Width="*"/>
                        </Grid.ColumnDefinitions>
                        <ScrollBar x:Name="PART_HorizontalScrollBar" Visibility="{TemplateBinding ComputedHorizontalScrollBarVisibility}" Grid.Column="1" Maximum="{TemplateBinding ScrollableWidth}" Value="{Binding HorizontalOffset, Mode=OneWay, RelativeSource={RelativeSource TemplatedParent}}" Orientation="Horizontal" ViewportSize="{TemplateBinding ViewportWidth}"/>
                    </Grid>
                </Grid>
            </ControlTemplate>
        </ScrollViewer.Template>
        <ItemsPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}"/>
    </ScrollViewer>
</Border>

Answer 2

try to set this to false in your TableView :

AllowScrollToFocusedRow="False"