列出要绑定的组合框的字符串

Question

why the combobox items is null,

 <ComboBox ItemsSource="{Binding Path=list}" ......>

so

public List<string> _list = new List<string>();

        public List<string> list
        {
            get
            {
                return _list;
            }
            set 
            {
                _list = value;
            }
        }

and add new item

while (combodata.Read())
 {
   list.Add(combodata.GetString(0));
 }

I think the need to use INotifyPropertyChanged or DependencyProperty but I do not know how this, please help me people!

Answer 1

A List does not provide notification when items are added / removed. You need to use a collection class that implements INotifyCollectionChanged . Try using an ObservableCollection instead:

public ObservableCollection <string> _list = new ObservableCollection <string>();

Answer 2

使用ObservableCollection <>或在“ while（combodata.Read（））”之后引发OnPropertyChanged（“ List”）。