有代码有J8：

UI

VM:

DelegateCommand
    
      _SelectionChangedCmd = null;public DelegateCommand
     
       SelectionChangedCmd{    get    {        if (this._SelectionChangedCmd == null)        {            this._SelectionChangedCmd = new DelegateCommand
      
       (SelectionChanged);        }        return this._SelectionChangedCmd;    }}void SelectionChanged(ListBox lst){    SelectedUser = lst.SelectedItem as User;}//这个就是选中项啦。User是自定义类public User SelectedUser { get; set; }