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Property ItemContainerStyle is used to add a item container style in which horizontal alignment is changed to stretch which makes the grid inside listview item to occupy the entire width of the screen.

XAML code of list view with data template containing grid (width = screen width)
ItemContainerStyle used to style grid present in listview

 <ListView  ItemsSource="{Binding FutureEvents}" ItemTemplate="{StaticResource EventItemTemplate}"
                                          SelectionMode="Single"  IsSwipeEnabled="True" IsItemClickEnabled="False" 
                                        ItemContainerStyle="{StaticResource ListViewItemStyle}" SelectedItem="{Binding SelectedEventForOtherInspection,Mode=TwoWay}" >
                                  
                                </ListView >


 <DataTemplate x:Key="EventItemTemplate">
      
        <Grid HorizontalAlignment="Stretch" >
            <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="0.5*" />
                <ColumnDefinition Width="0.5*" />
                  
            </Grid.ColumnDefinitions>
        </Grid>
      
    </DataTemplate>

 <Style x:Key="ListViewItemStyle" TargetType="ListViewItem">
        <Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}"/>
        <Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}"/>
        <Setter Property="Background" Value="Transparent"/>
        <Setter Property="TabNavigation" Value="Local"/>
        <Setter Property="IsHoldingEnabled" Value="True"/>
        <Setter Property="Margin" Value="0,0,0,0"/>
        <Setter Property="HorizontalContentAlignment" Value="Stretch"/>
        <Setter Property="VerticalContentAlignment" Value="Top"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="ListViewItem">
                    <ListViewItemPresenter CheckHintBrush="{ThemeResource ListViewItemCheckHintThemeBrush}" CheckBrush="{ThemeResource ListViewItemCheckThemeBrush}" ContentMargin="4" ContentTransitions="{TemplateBinding ContentTransitions}" CheckSelectingBrush="{ThemeResource ListViewItemCheckSelectingThemeBrush}" DragForeground="{ThemeResource ListViewItemDragForegroundThemeBrush}" DragOpacity="{ThemeResource ListViewItemDragThemeOpacity}" DragBackground="{ThemeResource ListViewItemDragBackgroundThemeBrush}" DisabledOpacity="{ThemeResource ListViewItemDisabledThemeOpacity}" FocusBorderBrush="{ThemeResource ListViewItemFocusBorderThemeBrush}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" Padding="{TemplateBinding Padding}" PointerOverBackgroundMargin="1" PlaceholderBackground="{ThemeResource ListViewItemPlaceholderBackgroundThemeBrush}" PointerOverBackground="{ThemeResource ListViewItemPointerOverBackgroundThemeBrush}" ReorderHintOffset="{ThemeResource ListViewItemReorderHintThemeOffset}" SelectedPointerOverBorderBrush="{ThemeResource ListViewItemSelectedPointerOverBorderThemeBrush}" SelectionCheckMarkVisualEnabled="True" SelectedForeground="{ThemeResource ListViewItemSelectedForegroundThemeBrush}" SelectedPointerOverBackground="{ThemeResource ListViewItemSelectedPointerOverBackgroundThemeBrush}" SelectedBorderThickness="{ThemeResource ListViewItemCompactSelectedBorderThemeThickness}" SelectedBackground="{ThemeResource ListViewItemSelectedBackgroundThemeBrush}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>