如何在xamarin中的MultiAutoCompleteTextView中获取最后一个搜索字母

Question

在multiselect中选择第一个值后，它不会在AutoCompleteTextView中显示搜索值，因为它取的是MultiAutoCompleteTextView Text的整个值。请帮我解决这个问题。

private MultiAutoCompleteTextView text;    
protected override void OnCreate(Bundle bundle)
    {
        base.OnCreate(bundle);
        SetContentView(Resource.Layout.Main);
       text = FindViewById<MultiAutoCompleteTextView>(Resource.Id.mulAuto);
       text.DropDownHeight = 500;
       text.Threshold = 1;
        text.TextChanged += text_TextChanged;

    }

  async void text_TextChanged(object sender, Android.Text.TextChangedEventArgs e)
    {
        List<string> str = new List<string>();
        HttpClient client = new HttpClient();
        string API = "http://" + IPAddress + "/api/Test/getdata?searchstr=" + e.Text;
        var data = await client.GetStringAsync(API);
        JSONArray array = new JSONArray(data);

        for (int i = 0; i < array.Length(); i++)
        {
            str.Add(array.GetJSONObject(i).GetString("Name"));
        }

        ArrayAdapter adapter = new ArrayAdapter<String>(this, Android.Resource.Layout.SimpleDropDownItem1Line, str);
        text.Adapter = adapter;
        text.SetTokenizer(new MultiAutoCompleteTextView.CommaTokenizer());
    }

取以前选择的值。另外，这是我的代码。