public class MyViewModel : INotifyPropertyChanged
    {
        private ObservableCollection<string> _testData;
        public ObservableCollection<string> TestData
        {
            get { return _testData; }
            set
            {
                _testData = value;
                OnPropertyChanged("TestData");
            }
        }
        public MyViewModel()
        {
            TestData= new ObservableCollection<string>();
            TestData.Add("name1");
            TestData.Add("name2");
            TestData.Add("name3");
            
        }
        public event PropertyChangedEventHandler PropertyChanged;
        private void OnPropertyChanged(String propertyName)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(propertyName));
            }
        }
    }