的ObservableCollection＆LT;＆GT;删除项目后列表不会更新

Question

我想删除TreeView中绑定了ObservableCollection<TreeNode> TreeViewNode,类型TreeNode的{​​{1}}项。但是，当我删除项TreeViewNodes.Remove(_item);时，列表不会更新。

我用：

public class TreeNode: TreeViewItem
{
    public string Type { get; set; }
    public string Name { get; set; }       
}

public event PropertyChangedEventHandler PropertyChanged;

[NotifyPropertyChangedInvocator]
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
    PropertyChangedEventHandler handler = PropertyChanged;
    if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}