选定的ListviewItem在Xamarin.Forms中保持选中状态

Question

我有以下XAML代码：

  <ListView x:Name="listView"
                      Grid.Row="1"
                      HasUnevenRows="True"
                      ItemsSource="{Binding DataList}"
                      SelectedItem="{Binding SelectedData}">
                <ListView.ItemTemplate>
                    <DataTemplate>
                        <ViewCell>
                            <ViewCell.View>
                                <StackLayout HorizontalOptions="FillAndExpand"
                                             Orientation="Horizontal"
                                             Padding="20,5,20,5">
                                    <StackLayout HorizontalOptions="StartAndExpand" Orientation="Vertical">

                                        <Label FontSize="Medium"
                                               HorizontalOptions="StartAndExpand"
                                               Text="{Binding Name}"
                                               VerticalTextAlignment="Start" />

                                        <StackLayout HorizontalOptions="StartAndExpand" Orientation="Horizontal">

                                            <Label FontSize="Small"
                                                   HorizontalOptions="StartAndExpand"
                                                   Text="{Binding Info1}"
                                                   VerticalTextAlignment="Start" />
                                            <Label FontSize="Small"
                                                   HorizontalOptions="StartAndExpand"
                                                   Text="{Binding Info2}"
                                                   VerticalTextAlignment="Start" />
                                        </StackLayout>
                                    </StackLayout>

                                    <Image HorizontalOptions="End"
                                           IsVisible="{Binding IsDone}"
                                           Source="Image1.png" />
                                </StackLayout>
                            </ViewCell.View>

                            <ViewCell.ContextActions>
                                <MenuItem Command="{Binding DeleteEntryCommand, Source={x:Reference listView}"
                                          CommandParameter="{Binding .}"
                                          IsDestructive="true"
                                          Text="Delete" />
                            </ViewCell.ContextActions>
                        </ViewCell>
                    </DataTemplate>
                </ListView.ItemTemplate>
            </ListView>

当我点击某个项目时，它会导航到新的页面。

public Data SelectedData
    {
      get { return selectedData; }
      set
      {
        selectedData= value;
        if(value!=null)
           navigationService.For<InfoViewModel>().Navigate();
        selectedData=null;
      }
    }

当我向后导航时， 该项目仍处于选中状态 ，因此我无法再次选择它。

如何让它“释放”该项？