Xamarin.Android SearchView can not see the CustomListView

Question

I can't connect search view and Custom List, When I searching the screen is blind. How Can I to do fix this?(C#)

1

2

My activity page;

Cont;

Answer 1

Hello,

Welcome to our Microsoft Q&A platform!

You should implement interface IFilterable for your CursorAdapter . I created a simple demo according to your code, it works properly on my side.

You can refer to the following code:

public class CursorAdapter:ArrayAdapter, IFilterable  
{  
    public Context c;  
    public List<Player> players;  
    public List<Player> _originalData;  

    public int resource;  
    public LayoutInflater inflater;  
    public Filter filter { get; private set; }  

    public CursorAdapter(Context context,int resource,List<Player> objects):base(context, resource, objects) {  

        this.c = context;  
        this.resource = resource;  
        this.players = objects;  
        filter = new SuggestionsFilter(this);  
        this._originalData = objects;  
    }  

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

    public void UpDateData(List<Player> temp)  
    {  
        players.Clear();  
        players.AddRange(temp);  
        NotifyDataSetChanged();  
    }  


    public override View GetView(int position, View convertView, ViewGroup parent)  
    {  
        View view = convertView; // re-use an existing view, if one is available  
        MyHolder holder;  

        if (view != null)  
        {  
            holder = view.Tag as MyHolder;  
            holder.NameTXT.Tag = position;  
        }  
        else  
        {  
            holder = new MyHolder();  

            LayoutInflater inflater = (LayoutInflater)c.GetSystemService(Context.LayoutInflaterService);  
            view = inflater.Inflate(resource, null);  

            holder.Img = view.FindViewById<ImageView>(Resource.Id.imageView1);  

            holder.NameTXT = view.FindViewById<TextView>(Resource.Id.mNameTxt);  
            holder.NameTXT.Tag = position;  

            view.Tag = holder;  
        }  

        Player player = players[position];  
        holder.NameTXT.Text = player.Name;  
        holder.Img.SetImageResource(player.Image);  

        return view;  
    }  

    class SuggestionsFilter : Filter  
    {  
        readonly CursorAdapter _adapter;  
        public SuggestionsFilter(CursorAdapter adapter) : base()  
        {  
            _adapter = adapter;  
        }  

        protected override FilterResults PerformFiltering(ICharSequence constraint)  
        {  
            var returnObj = new FilterResults();  
            var results = new List<Player>();  
            if (_adapter._originalData == null)  
                _adapter._originalData = _adapter.players;  

            if (constraint == null) return returnObj;  

            if (_adapter._originalData != null && _adapter._originalData.Any())  
            {  
                // Compare constraint to all names lowercased.   
                // It they are contained they are added to results.  
                results.AddRange(  
                    _adapter._originalData.Where(  
                        chemical => chemical.Name.ToLower().Contains(constraint.ToString())));  
            }  

            // Nasty piece of .NET to Java wrapping, be careful with this!  
            returnObj.Values = FromArray(results.Select(r => r.ToJavaObject()).ToArray());  
            returnObj.Count = results.Count;  

            constraint.Dispose();  

            return returnObj;  
        }  

        protected override void PublishResults(ICharSequence constraint, FilterResults results)  
        {  
            using (var values = results.Values)  
                _adapter.players = values.ToArray<Java.Lang.Object>()  
                    .Select(r => r.ToNetObject<Player>()).ToList();  

            _adapter.NotifyDataSetChanged();  

            // Don't do this and see GREF counts rising  
            constraint.Dispose();  
            results.Dispose();  
        }  
    }  

    public class MyHolder : Java.Lang.Object  
    {  
        public TextView NameTXT { get; set; }  
        public ImageView Img { get; set; }  
    }  
}  

class ObjectExtensions:

public class JavaHolder : Java.Lang.Object  
{  
    public readonly object Instance;  

    public JavaHolder(object instance)  
    {  
        Instance = instance;  
    }  
}  

public static  class ObjectExtensions  
{  

    public static TObject ToNetObject<TObject>(this Java.Lang.Object value)  
    {  
        if (value == null)  
            return default(TObject);  

        if (!(value is JavaHolder))  
            throw new InvalidOperationException("Unable to convert to .NET object. Only Java.Lang.Object created with .ToJavaObject() can be converted.");  

        TObject returnVal;  
        try { returnVal = (TObject)((JavaHolder)value).Instance; }  
        finally { value.Dispose(); }  
        return returnVal;  
    }  

    public static Java.Lang.Object ToJavaObject<TObject>(this TObject value)  
    {  
        if (Equals(value, default(TObject)) && !typeof(TObject).IsValueType)  
            return null;  

        var holder = new JavaHolder(value);  

        return holder;  
    }  
}  

Usage in activity:

     sv1.QueryTextChange += Sv1_QueryTextChange;  
    private void Sv1_QueryTextChange(object sender, SearchView.QueryTextChangeEventArgs e)  
    {  
        string word = e.NewText;  
        adapter.filter.InvokeFilter(word);  
    }  

Best Regards,

Jessie Zhang

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Answer 2

Hello,

Welcome to our Microsoft Q&A platform!

Try the following code,it works on my side.

1.method QueryTextChange

    private void MSearchViewBranch_QueryTextChange(object sender,SearchView.QueryTextChangeEventArgs e)  
    {  
        string word = e.NewText;  
        FindInsideList(word);  
    }  

2.Method FindInsideList:

    private void FindInsideList(string text)  
    {  
        if (text != null && text.Length > 0)  
        {  
            List<Photo> filteredList = new List<Photo>();  
            foreach (var itm in loadBranch)  
            {  
                if (itm != null)  
                {  
                    text = text.ToLower();  

                    if (itm.mCaption != null ? itm.mCaption.ToLower().Contains(text) : false)  
                    {  
                        filteredList.Add(itm);  
                    }  
                }  
            }  
            mAdapter.UpDateData(filteredList);  
        }  
        else  
        {  
            mAdapter.UpDateData(loadBranch);  
        }  
    }  

3.UpDateData is a method in my Adapter

    public void UpDateData(List<Photo> temp)  
    {  
        mPhotoAlbum = temp;  
        NotifyDataSetChanged();  
    }  

Note:

1. mAdapter is my adapter and Photo is my item model
   2.loadBranch is the data list filled into my RecyclerView .

    List<Photo> loadBranch = new List<Photo>();  
   
   mAdapter = new PhotoAlbumAdapter(loadBranch);  
   

Best Regards,

Jessie Zhang

---

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Answer 3

Hello,

try to refresh the adapter -> adapter.NotifyDataSetChanged();