Caliburn Micro中的墓碑

Question

我有MainPageViewModel与Items(ObservableCollection).在这个页面上,我还有一个按钮,可以向项目中添加新项目.

public class MainPageViewModel : Screen {
  private DateTime StartActivity = DateTime.MinValue;

  public ObservableCollection<ActivityViewModel> Items { get; set; }

  public MainPageViewModel(INavigationService navigationService) {
    this.Items = new ObservableCollection<ActivityViewModel>();
  }

  public void AddActivity(string activityName) {
    if (this.Items.Count == 0) {
      this.Items.Add(new ActivityViewModel() { 
        Activity = activityName, 
        Duration = 0 
      });

      StartActivity = DateTime.Now;
      }
    else {
      this.Items[this.Items.Count - 1].Duration = 10;
      this.Items.Add(new ActivityViewModel() { 
        Activity = activityName,
        Duration = 0 
      });

      StartActivity = DateTime.Now;
    }
  }
}

添加新项目非常有效.

但是,在逻辑删除后应用程序激活时,来自项目的数据无法恢复.尝试为我的ViewModel创建StorageHandler.没有帮助.我做错了什么？

public class MainPageViewModelStorage : StorageHandler<MainPageViewModel> {
  public override void Configure() {
    Property(x => x.Items)
        .InAppSettings()
        .RestoreAfterActivation();
  }
}

另外,尝试为类和属性添加[SurviveTombstone],但Visual Studio不知道该属性.

public class ActivityViewModel : PropertyChangedBase {
  private string _activity;
  public string Activity {
    get {
      return _activity;
    }
    set {
      if (value != _activity) {
        _activity = value;
        NotifyOfPropertyChange(() => Activity);
      }
    }
  }

  private double _duration;
  public double Duration {
    get {
      return _duration;
    }
    set {
      if (value != _duration) {
        _duration = value;
        NotifyOfPropertyChange(() => Duration);
      }
    }
  }
}

Answer 1

1. 你不应该存储InAppSettings但是InPhoneState。
2. 检查断点是否Configure调用了方法。如果没有 - 你的引导程序有问题。可能PhoneContainer.RegisterPhoneServices()失踪了
3. 在 Visual Studio 中打开捕获第一次机会异常（Ctrl+Alt+E，并勾选 CLR 异常）。您的视图模型可能无法正确反序列化。