如何处理LongListMultiSelector的选定项目？

Question

I want to be able:

• to open a mail when the user taps on one item.
• and delete multiple emails when the user selects multiple emails

So I choosed LongListMultiSelector .

In built in LongListSelector , I handle the SelectionChanged event like this:

private void mails_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    var selectedItem = mailsLongListSelector.SelectedItem as Mail;

    if (selectedItem == null)
        return;
    ...
    mailsLongListSelector.SelectedItem = null;
}

I want exactly like that functionality in wptoolkit's LongListMultiSelector . like when you select an email to open and read it.

LongListMultiSelector 's SelectionChanged occurs when you tap left side of an item and checkboxes appear. this is not what I want.

The Question is: How can I perform something when the user taps on one item of LongListMultiSelector ? thanks.

Answer 1

You could try this. If this is your LongListSelector

<tkit:LongListMultiSelector Name="longlist" SelectionChanged="longlist_SelectionChanged">
    <tkit:LongListMultiSelector.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Title}" FontSize="32" Tap="TextBlock_Tap"/>
        </DataTemplate>
    </tkit:LongListMultiSelector.ItemTemplate>
</tkit:LongListMultiSelector>

and it has an itemtemplate, you can detect a tap on item.

private void TextBlock_Tap(object sender, System.Windows.Input.GestureEventArgs e)
{
    var itemTapped = (sender as FrameworkElement).DataContext as Book;
}

and still have a selection changed

private void longlist_SelectionChanged(object sender, SelectionChangedEventArgs e)
{

}

Answer 2

Once you are using LongListMultiSelector, the SelectionChanged event is fired when item is added or removed. If you want to perform the action regardless item is added/removed, I've managed to do it like this (for a simple string):

private void longlist_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
    string selectedItem = String.Empty;
    if (e.AddedItems.Count > 0) selectedItem = e.AddedItems[0] as string;
    else selectedItem = e.RemovedItems[0] as string;
    MessageBox.Show(selectedItem); // do your work
}

It should run while items are selected separately by tapping, but this method will have problems when more items are added/removed at the same time - if you need it, then you should handle this also.