Xamarin Android：ListView按钮点击获位置及Fragment按钮实现

Got it, let's break down solutions for both of your requirements clearly:

1. Get ListView Item Position When Clicking a Button Inside the Item #

Since you're using a BaseAdapter<Quotes> for your ListView, you'll handle the button click directly in the adapter's GetView method. Here's how to implement it properly:

First, complete your adapter's GetView method (I'll fill in the missing parts for you):

public class HomeScreenAdapter : BaseAdapter<Quotes> 
{ 
    List<Quotes> items; 
    Activity context; 

    public HomeScreenAdapter(Activity context, List<Quotes> items) : base() 
    { 
        this.context = context; 
        this.items = items; 
    } 

    public override long GetItemId(int position) 
    { 
        return position; 
    } 

    public override Quotes this[int position] 
    { 
        get { return items[position]; } 
    }

    public override int Count 
    { 
        get { return items.Count; } 
    }

    public override View GetView(int position, View convertView, ViewGroup parent)
    {
        // Reuse view if possible (ViewHolder pattern is better for performance, but this works for basics)
        View view = convertView ?? context.LayoutInflater.Inflate(Resource.Layout.YourListItemLayout, parent, false);
        
        // Get the current quote item
        Quotes currentQuote = items[position];

        // Locate your button in the list item layout
        Button itemButton = view.FindViewById<Button>(Resource.Id.your_button_id);

        // Option 1: Use Tag to store position (most reliable to avoid closure issues)
        itemButton.Tag = position;
        itemButton.Click += (sender, e) =>
        {
            int clickedPosition = (int)((Button)sender).Tag;
            Quotes clickedItem = items[clickedPosition];
            
            // Do whatever you need with the position/item
            Toast.MakeText(context, $"Clicked item at position: {clickedPosition}", ToastLength.Short).Show();
        };

        // Option 2: Directly capture the position variable (works here since GetView is called per item)
        // itemButton.Click += (sender, e) =>
        // {
        //     Toast.MakeText(context, $"Clicked item at position: {position}", ToastLength.Short).Show();
        // };

        // Bind other data to your list item views (example)
        TextView quoteText = view.FindViewById<TextView>(Resource.Id.quote_text);
        quoteText.Text = currentQuote.QuoteText;

        return view;
    }
}

Key Notes: #

• Using the Tag property is safer for avoiding unexpected behavior with closures, especially if you're reusing views via convertView.
• For better performance, consider implementing the ViewHolder pattern to avoid repeated FindViewById calls.

2. Implement Button Click in Fragment's OnCreateView Method #

In your Fragment, you'll inflate the layout first, then locate the button and attach a click handler. Here's the code:

public class HomeFragment : Fragment
{
    public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        // Inflate your fragment's layout
        View fragmentView = inflater.Inflate(Resource.Layout.HomeFragmentLayout, container, false);

        // Find the button in the fragment layout
        Button fragmentButton = fragmentView.FindViewById<Button>(Resource.Id.fragment_button_id);

        // Attach click event handler
        fragmentButton.Click += FragmentButton_Click;

        return fragmentView;
    }

    // Separate click handler method (cleaner than anonymous delegates for complex logic)
    private void FragmentButton_Click(object sender, EventArgs e)
    {
        // Handle the button click here
        // Use Activity property to get the context for Toast/other operations
        Toast.MakeText(Activity, "Fragment button clicked successfully!", ToastLength.Short).Show();
        
        // Example: If you need to communicate with the parent Activity, use an interface or ViewModel
    }

    // Alternatively, use an anonymous delegate for simple logic:
    // fragmentButton.Click += (sender, e) =>
    // {
    //     Toast.MakeText(Activity, "Fragment button clicked!", ToastLength.Short).Show();
    // };
}

Key Notes: #

• Always use Activity (or Context) from the Fragment instead of ApplicationContext to prevent memory leaks.
• For more complex interactions between Fragment and Activity, consider using interfaces or a shared ViewModel.

内容的提问来源于stack exchange，提问作者Fatihi Youssef