Xamarin Forms ListView：访问ViewCell的对象数据

Question

I'm new to Xamarin and I'm facing a problem using a ListView to list posts, like Facebook.

I've made a class Post and it works as it should, but now I want to interact with posts (example: like, comment) and for that I have to access each ListView Item values to process it in the database.

How can I acess the item's data?

Feed.xaml.cs

ObservableCollections<Post> posts;

//Binding data to ListView
postsList.ItemSource = posts;

posts.Add(new Post{ Key = "key_example", Title = "title_example", Img = "http://example.example"});

///////if i do the following, it gives me a null pointer exception\\\\\\\\

this.LoadFromXaml(typeof(Feed));
Image image = this.FindByName<Image>("key_image")

Feed.xaml

<ListView x:Name="postsList">
   <ListView.ItemTemplate>
       <DataTemplate>
          <ViewCell>
             <ViewCell.View>
                <Label Text = { Binding Title } />
                <Image x:Name = "key_image"/>
                <Button /> //CALLS FUNCTION IN .cs WITH key VALUE FROM CURRENT POST
             </ViewCell.View>
          </ViewCell>
       </DataTemplate>
   </ListView.ItemTemplate>
</ListView>

Answer 1

this will bind the Button's CommandParameter property to the relevant Post object

<Button CommandParameter="{Binding .}" Text="Blah" />

then in your click handler or command you can reference the CommandParameter and cast it to Post.