简体   繁体   中英

How to get clicked item from LongListSelector? (WP8)

I have a LongListSelector that is binded with ObservableCollection of some kind of Items. Items have many different properties.

 <LongListSelector Name="DraftControl"  MouseLeftButtonDown="GoToEditDraft"> 
     <LongListSelector.ItemTemplate>
         <DataTemplate>
             ...
         </DataTemplate>
     <LongListSelector.ItemTemplate>
  </LongListSelector>

It has an event handler. But it gets as sender the whole LongListSelector, not a particular item. How to add event handler for all items?

Here is a handler's code:

 private void GoToEditDraft(object sender, MouseButtonEventArgs mouseButtonEventArgs)
    {
        var clickerdItem = (LongListSelector)sender;
        MessageBox.Show(clickedItem.SelectedItem.ToString());
    }

So, trying to get SelectedItem this way throws NullReferenceException.

Data template:

 <DataTemplate>
 <Grid Margin="10" toolkit:TiltEffect.IsTiltEnabled="True">
     <Grid.Background>
         <SolidColorBrush Color="LightGray" Opacity="0.8"/>
     </Grid.Background>
     <Grid.ColumnDefinitions>
         <ColumnDefinition Width="120"/>
         <ColumnDefinition Width="*"/>
     </Grid.ColumnDefinitions>
     <Grid.RowDefinitions>
         <RowDefinition Height="Auto"/>
         <RowDefinition MaxHeight="100"/>
         <RowDefinition MaxHeight="30"/>
     </Grid.RowDefinitions>
     <TextBlock TextWrapping="Wrap" FontSize="28" Foreground="{StaticResource CustomApplicationTextBrush}" Text="{Binding Title, Converter={StaticResource SanitizeString}}" Margin="10,10,10,0" Grid.Column="0" Grid.Row="0" Grid.ColumnSpan="2"/>
     <Image Source="/Images/no-image.png" Stretch="UniformToFill" MaxHeight="100" Margin="10,10,0,10" Grid.RowSpan="1" Grid.Column="0" Grid.Row="1" VerticalAlignment="Top"/>
     <TextBlock TextWrapping="Wrap" FontSize="18" Foreground="{StaticResource CustomApplicationTextBrush}" TextTrimming="WordEllipsis" Text="{Binding Address, Converter={StaticResource SanitizeString}}" Margin="10,0,10,10" Grid.Column="1" Grid.Row="1" VerticalAlignment="Top"/>
 </Grid>
 </DataTemplate>

Binding:

        ObservableCollection<Item> draftItems = new ObservableCollection<Item>();
        var draftStorage = IsolatedStorageFile.GetUserStoreForApplication();
        IReadOnlyList<StorageFile> allDrafts = await draftFolder.GetFilesAsync();
        foreach (StorageFile file in allDrafts)
        {                
            using (var stream = new IsolatedStorageFileStream("Drafts\\" + file.Name, FileMode.Open, draftStorage))
            {
                var fileReader = new StreamReader(stream);
                string jsonContents = fileReader.ReadLine();
                Item readedItem = JsonConvert.DeserializeObject<Item>(jsonContents);

                draftItems.Add(readedItem);
                fileReader.Close();
            }
        }
        DraftControl.ItemsSource = draftItems;

Try this.

private void DraftControl_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    var myItem = ((Item)(sender as LongListSelector).SelectedItem);
}

Subscribe to LongListSelectors SelectionChangedEvent rather

<LongListSelector Name="DraftControl" SelectionChanged="lls_SelectionChanged"> 
     <LongListSelector.ItemTemplate>
         <DataTemplate>
             ...
         </DataTemplate>
     <LongListSelector.ItemTemplate>
  </LongListSelector>

and get the item in the code behind

private void lls_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
  var myItem = ((LongListSelector) sender).SelectedItem as Type;
}

The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.

 
粤ICP备18138465号  © 2020-2024 STACKOOM.COM