Custom Arrayadapter with Custom Filter

问题

I will give you a short review about what i'm trying to do: I want to fill the DropDown of a AutoCompleteTextView with my own Objects. those objects contain 3 Strings. In the list_item_view should be 2 of the strings. This List should be filterable.

Now a bit of code, what i've done till now:

My CustomAdapter looks like this:

public class CustomerAdapter : ArrayAdapter<CustomerSingle>, IFilterable
{
    private ws_test.Test ws=null;
    public static List<CustomerSingle> _contactList;
    private Activity _activity;
    private CustomerAdapterFilter filter = null;

    public CustomerAdapter(Activity activity, Context context,int resourceId)//List<CustomerSingle> assets)
    :base(context,resourceId)//,assets)
    {
        _activity = activity;
        ws=new ws_test.Test();
        _contactList = new List<CustomerSingle>();
    }

    public static List<CustomerSingle> getCustomerList()
    {
        return _contactList;
    }

    public void Add(CustomerSingle item)
    {
         _contactList.Add(item);
    }

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

    public override long GetItemId(int position)
    {
        return _contactList[position].id;
    }

    public override View GetView(int position, View convertView, ViewGroup parent)
    {
        var view = convertView ?? _activity.LayoutInflater.Inflate(Resource.Layout.details, parent, false);
        var contactName = view.FindViewById<TextView>(Resource.Id.Name);
        var contactAddress = view.FindViewById<TextView>(Resource.Id.Address);
        contactName.Text = _contactList[position].name;// +"\n" + _contactList[position].address;
        contactAddress.Text = _contactList[position].address;

        return view;
    }

    public override Filter Filter
    {
        get
        {
            return new CustomerAdapterFilter();
        }
    }

    public override void NotifyDataSetChanged()
    {
        base.NotifyDataSetChanged();
    }

    public override void NotifyDataSetInvalidated()
    {
        base.NotifyDataSetInvalidated();
    }
}

The CustomerSingle looks like this:

public class CustomerSingle
{
    public string no { get; set; }
    public string name { get; set; }
    public string address { get; set; }
    public int id { get; set; }

    public CustomerSingle(string no, string name, string address, int id)
    {
        this.address = address;
        this.name = name;
        this.no = no;
        this.id = id;
    }
}

Ok, now I need an own Filter what i'm trying to do here:

public class CustomerAdapterFilter:Filter
{
    protected object mLock = new object();
    protected List<CustomerSingle> mOriginalValues = null;

    protected override FilterResults PerformFiltering(Java.Lang.ICharSequence prefix)
    {

        FilterResults results = new FilterResults();
        if (mOriginalValues == null) {
            lock(mLock) {
                mOriginalValues = new List<CustomerSingle>(CustomerAdapter._contactList);

            }
        }

        if (prefix == null || prefix.Length() == 0) {
            lock (mLock) {
                List<CustomerSingle> list = new List<CustomerSingle>(mOriginalValues);
                IntPtr listptr = list.
                results.Values = list;
                results.Count = list.Count;
            }
        } else {
            String prefixString = prefix.ToString().ToLowerInvariant();

            List<CustomerSingle> values = mOriginalValues;
            int count = values.Count;

            List<CustomerSingle> newValues = new List<CustomerSingle>(count);

            for (int i = 0; i < count; i++) {
                CustomerSingle value = values.ElementAt(i);
                String valueText = value.ToString().ToLowerInvariant();

                // First match against the whole, non-splitted value
                if (valueText.StartsWith(prefixString)) {
                    newValues.Add(value);
                } else {
                    String[] words = valueText.Split(' ');
                    int wordCount = words.Length;

                    for (int k = 0; k < wordCount; k++) {
                        if (words[k].StartsWith(prefixString)) {
                            newValues.Add(value);
                            break;
                        }
                    }
                }
            }

            results.Values = (Object) newValues;
            results.Count = newValues.Count;
        }

        return results;
    }

    protected override void PublishResults(Java.Lang.ICharSequence constraint, Filter.FilterResults results)
    {
        //noinspection unchecked
        var mObjects = results.Values;
        if (results.Count > 0)
        {
            NotifyDataSetChanged();
        }
        else
        {
            notifyDataSetInvalidated();
        }
    }
}

My problem is, I can't Convert from Java.Lang.Object to my CustomerSingle... Does someone have an Idea?

Thank you!

Update: I changed to JavaList in the filter and did the extension to Java.Lang.Object at the CustomerSingle

回答1:

Make your CustomerSingle class subclass Java.Lang.Object:

public class CustomerSingle : Java.Lang.Object

UPDATE:

My guess is that this line:

results.Values = (Object) newValues;

is trying to convert to System.Object instead of Java.Lang.Object, try (Java.Lang.Object) instead.

来源：https://stackoverflow.com/questions/10121581/custom-arrayadapter-with-custom-filter