在viewmodel中使用单音崩溃

Question

我有目前的用户（在我的应用程序是医生）：

sealed class CurrentDataStorage
    {

        private static CurrentDataStorage dataStorage;

        private CurrentDataStorage()
        {

        }

        public static CurrentDataStorage DataStorage
        {
            get
            {
                if(dataStorage == null)
                {
                    dataStorage = new CurrentDataStorage();
                }
                return dataStorage;
            }
        }



        public Doctor CurrentDoctor { get
            {
                return CurrentDoctor;
            }
            set
            {
                if(CurrentDoctor != value)
                    CurrentDoctor = value;
            }
        }
    }

如果我在viewmodel类中使用它，我的应用程序就会崩溃。也许医生是空的。我在授权页面中创建了一些医生（它是用户在后端创建的存根）：

public void OnAuthorization(object sender, EventArgs a)
        {
            CurrentDataStorage.DataStorage.CurrentDoctor = new Doctor("Иван", "Иванов", "Иванович", "[e-mail]", "superdoctor321",
                        "Princeton Plainsboro", Model.Enums.Position.Researcher, Model.Enums.Category.Highest, Model.Enums.AcademicDegree.Doctor);
            Application.Current.MainPage = new ProfilePage();
        }

页面代码如下所示：

public ProfilePageMaster()
        {
            InitializeComponent();

            this.BindingContext = new ProfilePageMasterViewModel();
        }

        class ProfilePageMasterViewModel : INotifyPropertyChanged
        {
            Doctor doctor;

            public ProfilePageMasterViewModel()
            {
                doctor = CurrentDataStorage.DataStorage.CurrentDoctor;
            }

            public String FullName
            {
                get
                {
                    return doctor.FullName;
                }
            }

            #region INotifyPropertyChanged Implementation
            public event PropertyChangedEventHandler PropertyChanged;
            void OnPropertyChanged([CallerMemberName] string propertyName = "")
            {
                if (PropertyChanged == null)
                    return;

                PropertyChanged.Invoke(this, new PropertyChangedEventArgs(propertyName));
            }
            #endregion
        }

我在使用单例中做错了什么？

UPD：这份坠机报告（它什么都没告诉我）

构建指纹：“小米/kenzo/kenzo:6.0.1/MMB29M/8.11.8:用户/释放密钥”修订版：“0”ABI:“arm64”pid:10207，tid:10207，名称：hecksorexamarin

回溯：#00 pc 0000000000019d54/system/lib64/libc。所以（memcpy 332）#01 pc 0000000000 1094F4/data/app/Mono。AndroidDebugRuntime-1/lib/arm64/libmonosgen-64bit-2.0。所以

Answer 1

你的错误很可能与单身无关。你的财产是杀手——它正在访问自己：

public Doctor CurrentDoctor 
 { 
    get
    {
       return CurrentDoctor;
    }
    set
    {
         if(CurrentDoctor != value)
            CurrentDoctor = value;
    }
 }

使用支持字段

 private Doctor _currentDoctor
 public Doctor CurrentDoctor 
 { 
    get
    {
       return _currentDoctor;
    }
    set
    {
         if(_currentDoctor != value)
            _currentDoctor = value;
    }
 }