我正在开发 WPF MVVM 应用程序。我有一个显示在主区域内的视图（员工），这个视图（员工）在其中包含我显示/显示员工详细信息视图的范围区域。它工作正常，直到这个地方新，显示更新和删除
但是我遇到了新操作的奇怪问题如果我第一次创建视图并单击 new ，对象会初始化我的数据对象 CurrentEmployee。但是如果我加载一些以前的数据，它会正确显示，然后我点击新建，我的数据对象 CurrentEmployee 花费了太多时间，最终崩溃了。到目前为止追踪的问题在于 OnPropertyChange
感谢任何形式的帮助/建议都非常受欢迎
视图模型的完整代码
[Export(typeof(ITB_EMPLOYEEViewModel))]
public class TB_EMPLOYEEViewModel : ViewModelBase, ITB_EMPLOYEEViewModel
{
private TB_EMPLOYEE _currentTB_EMPLOYEE;
IRegionManager RefRegionManager;
IEventAggregator _eventAggregator;
[ImportingConstructor]
public TB_EMPLOYEEViewModel(IRegionManager regionManager, IEventAggregator eventAggregator)
: base(regionManager, eventAggregator)
{
RefRegionManager = regionManager;
HeaderInfo = "TB_EMPLOYEE";
_eventAggregator = eventAggregator;
OpenImageDialog = new DelegateCommand(OpenDialog, CanOpenDialog);
//CurrentTB_EMPLOYEE = new TB_EMPLOYEE();
//empHistoryVM = new TB_EMPLOYEE_HISTORYViewModel();
//UnLoadChild();
//LoadChild();
New();
}
private void LoadChild()
{
IRegionManager regionManager = ServiceLocator.Current.GetInstance<IRegionManager>();
if (regionManager.Regions.ContainsRegionWithName(RegionNames.EmployeeDetail))
{
IRegion region = regionManager.Regions[RegionNames.EmployeeDetail];
var empHistory = ServiceLocator.Current.GetInstance<uTB_EMPLOYEE_HISTORYView>();
if (region.GetView("EmployeeHistory") == null)// .Views.OfType<uTB_EMPLOYEE_HISTORYView>().SingleOrDefault() == null)
{
region.Add(empHistory, "EmployeeHistory");
}
if (CurrentTB_EMPLOYEE != null && CurrentTB_EMPLOYEE.ID!=0)
{
empHistoryVM = new TB_EMPLOYEE_HISTORYViewModel(CurrentTB_EMPLOYEE.ID);
}
else
{
empHistoryVM = new TB_EMPLOYEE_HISTORYViewModel();
}
empHistory.ViewModel = empHistoryVM;
region.Activate(region.GetView("EmployeeHistory"));
}
}
private void UnLoadChild()
{
IRegionManager regionManager = ServiceLocator.Current.GetInstance<IRegionManager>();
if (regionManager.Regions.ContainsRegionWithName(RegionNames.EmployeeDetail))
{
IRegion region = regionManager.Regions[RegionNames.EmployeeDetail];
if (region.GetView("EmployeeHistory") != null)// .Views.OfType<uTB_EMPLOYEE_HISTORYView>().SingleOrDefault() == null)
{
region.Remove(region.GetView("EmployeeHistory"));
}
}
}
#region DetailUserControls ViewModels
private TB_EMPLOYEE_HISTORYViewModel empHistoryVM;
#endregion DetailUserControls ViewModels
#region Commands
public DelegateCommand OpenImageDialog { get; set; }
private bool CanOpenDialog() { return true; }
public void OpenDialog()
{
using (OpenFileDialog objOpenFile = new OpenFileDialog())
{
if (objOpenFile.ShowDialog() == DialogResult.OK)
{
_currentTB_EMPLOYEE.PHOTO = Utility.ConvertImageToByte(objOpenFile.FileName);
CurrentEmployeeImage = Utility.ConvertByteToImage(_currentTB_EMPLOYEE.PHOTO);
}
}
}
public override void ShowSelectedRow()
{
if (RefRegionManager.Regions[RegionNames.MainRegion].Views.OfType<uTB_EMPLOYEEView>().SingleOrDefault() == null)
{
RefRegionManager.RegisterViewWithRegion(RegionNames.MainRegion, typeof(uTB_EMPLOYEEView));
}
RefRegionManager.RequestNavigate(RegionNames.MainRegion, "uTB_EMPLOYEEView");
UnLoadChild();
LoadChild();
}
public override void RegisterCommands()
{
if (RefRegionManager.Regions[RegionNames.MainRegion].ActiveViews.OfType<uTB_EMPLOYEEView>().FirstOrDefault() != null)
{
if (RefRegionManager.Regions[RegionNames.MainRegion].ActiveViews.OfType<uTB_EMPLOYEEView>().FirstOrDefault().ToString() == "WPFApp.View.uTB_EMPLOYEEView")
{
GlobalCommands.ShowAllCommand.RegisterCommand(ShowAllCommand);
GlobalCommands.SaveCommand.RegisterCommand(SaveCommand);
GlobalCommands.NewCommand.RegisterCommand(NewCommand);
GlobalCommands.DeleteCommand.RegisterCommand(DeleteCommand);
GlobalCommands.CloseCommand.RegisterCommand(CloseCommand);
}
}
if (RefRegionManager.Regions[RegionNames.MainRegion].ActiveViews.OfType<uListTB_EMPLOYEE>().FirstOrDefault() != null)
{
if (RefRegionManager.Regions[RegionNames.MainRegion].ActiveViews.OfType<uListTB_EMPLOYEE>().FirstOrDefault().ToString() == "WPFApp.ListView.uListTB_EMPLOYEE")
{
GlobalCommands.CloseCommand.RegisterCommand(CloseCommand);
GlobalCommands.SearchCommand.RegisterCommand(SearchCommand);
GlobalCommands.PrintCommand.RegisterCommand(PrintCommand);
GlobalCommands.ExportToExcelCommand.RegisterCommand(ExportToExcelCommand);
GlobalCommands.ExportToWordCommand.RegisterCommand(ExportToWordCommand);
GlobalCommands.ExportToPDFCommand.RegisterCommand(ExportToPDFCommand);
}
}
}
public override bool CanShowAll()
{
return IsActive;
}
public override void ShowAll()
{
HeaderInfo = "TB_EMPLOYEE List";
if (RefRegionManager.Regions[RegionNames.MainRegion].Views.OfType<uListTB_EMPLOYEE>().SingleOrDefault() == null)
{
RefRegionManager.RegisterViewWithRegion(RegionNames.MainRegion, typeof(uListTB_EMPLOYEE));
}
RefRegionManager.RequestNavigate(RegionNames.MainRegion, "uListTB_EMPLOYEE");
UpdateListFromDB();
}
public override void UpdateListFromDB()
{
using (DBMain objDBMain = new DBMain())
{
TB_EMPLOYEEList = objDBMain.EntTB_EMPLOYEE.ToList<TB_EMPLOYEE>();
}
}
public override void New()
{
this.CurrentTB_EMPLOYEE = new TB_EMPLOYEE();
UnLoadChild();
LoadChild();
}
public override void Close()
{
if (RefRegionManager.Regions[RegionNames.MainRegion].ActiveViews.OfType<uTB_EMPLOYEEView>().FirstOrDefault() != null)
{
if (RefRegionManager.Regions[RegionNames.MainRegion].ActiveViews.OfType<uTB_EMPLOYEEView>().FirstOrDefault().ToString() == "WPFApp.View.uTB_EMPLOYEEView")
{
RefRegionManager.Regions[RegionNames.MainRegion].Remove(RefRegionManager.Regions[RegionNames.MainRegion].ActiveViews.OfType<uTB_EMPLOYEEView>().FirstOrDefault());
UnLoadChild();
}
}
if (RefRegionManager.Regions[RegionNames.MainRegion].ActiveViews.OfType<uListTB_EMPLOYEE>().FirstOrDefault() != null)
{
if (RefRegionManager.Regions[RegionNames.MainRegion].ActiveViews.OfType<uListTB_EMPLOYEE>().FirstOrDefault().ToString() == "WPFApp.ListView.uListTB_EMPLOYEE")
{
RefRegionManager.Regions[RegionNames.MainRegion].Remove(RefRegionManager.Regions[RegionNames.MainRegion].ActiveViews.OfType<uListTB_EMPLOYEE>().FirstOrDefault());
}
}
}
public override void Delete()
{
if (RefRegionManager.Regions[RegionNames.MainRegion].ActiveViews.OfType<uTB_EMPLOYEEView>().FirstOrDefault() != null ||
RefRegionManager.Regions[RegionNames.MainRegion].ActiveViews.OfType<uListTB_EMPLOYEE>().FirstOrDefault() != null)
{
if (CurrentTB_EMPLOYEE != null)
{
ConfirmationDialog confirmationMessage = new ConfirmationDialog("Do You want to Delete this Record of [TB_EMPLOYEE]", "Confirmation Dialog Box");
confirmationMessage.AllowsTransparency = true;
DoubleAnimation animFadeIn = new DoubleAnimation();
animFadeIn.From = 0;
animFadeIn.To = 1;
animFadeIn.Duration = new Duration(TimeSpan.FromSeconds(1));
confirmationMessage.BeginAnimation(Window.OpacityProperty, animFadeIn);
confirmationMessage.ShowDialog();
if (confirmationMessage.DialogValue)
{
if (CurrentTB_EMPLOYEE.ID != 0)
{
using (DBMain objDBMain = new DBMain())
{
objDBMain.Entry<TB_EMPLOYEE>(CurrentTB_EMPLOYEE).State = EntityState.Deleted;
objDBMain.SaveChanges();
OnPropertyChanged("CurrentTB_EMPLOYEE");
CurrentTB_EMPLOYEE = null;
}
}
else
{
CurrentTB_EMPLOYEE = null;
}
UpdateListFromDB();
}
}
}
}
public override bool CanSave()
{
return IsActive;
}
public override void Save()
{
if (RefRegionManager.Regions[RegionNames.MainRegion].ActiveViews.OfType<uTB_EMPLOYEEView>().FirstOrDefault() != null ||
RefRegionManager.Regions[RegionNames.MainRegion].ActiveViews.OfType<uListTB_EMPLOYEE>().FirstOrDefault() != null)
{
if (CurrentTB_EMPLOYEE != null)
{
using (DBMain objDBMain = new DBMain())
{
objDBMain.Entry<TB_EMPLOYEE>(CurrentTB_EMPLOYEE).State = CurrentTB_EMPLOYEE.ID == 0 ? EntityState.Added : EntityState.Modified;
foreach (TB_EMPLOYEE_HISTORY obj in empHistoryVM.TB_EMPLOYEE_HISTORYList)
{
objDBMain.Entry<TB_EMPLOYEE_HISTORY>(obj).State = EntityState.Added;
CurrentTB_EMPLOYEE.TB_EMPLOYEE_HISTORYList.Add(obj);
objDBMain.SaveChanges();
}
}
UpdateListFromDB();
}
}
}
#endregion Commands
#region Properties
private ImageSource _CurrentEmployeeImage;
public ImageSource CurrentEmployeeImage { get { return _CurrentEmployeeImage; } private set { _CurrentEmployeeImage = value; OnPropertyChanged("CurrentEmployeeImage"); } }//OnPropertyChanged("CurrentTB_EMPLOYEE");
public string CurrentEmployeeImagePath { get; set; }
private List<TB_EMPLOYEE> _TB_EMPLOYEEList;
public List<TB_EMPLOYEE> TB_EMPLOYEEList
{
get { return _TB_EMPLOYEEList; }
set
{
_TB_EMPLOYEEList = value;
RaisePropertyChanged();
}
}
public TB_EMPLOYEE CurrentTB_EMPLOYEE
{
get { return _currentTB_EMPLOYEE; }
set
{
_currentTB_EMPLOYEE = value;
if (_currentTB_EMPLOYEE != null && _currentTB_EMPLOYEE.PHOTO != null)
{ CurrentEmployeeImage = Utility.ConvertByteToImage(_currentTB_EMPLOYEE.PHOTO); }
//OnPropertyChanged("CurrentTB_EMPLOYEE");
RaisePropertyChanged();
}
}
private IList<TB_SETUP_RELIGION> _listRELIGION;
public IList<TB_SETUP_RELIGION> listRELIGION
{
get
{
using (DBMain objDBMain = new DBMain())
{
_listRELIGION = objDBMain.EntTB_SETUP_RELIGION.ToList();
}
return _listRELIGION;
}
}
private IList<string> _listTitles;
public IList<string> listTitles
{
get
{
if (_listTitles == null)
{
_listTitles = new List<string>();
_listTitles.Add("Mr");
_listTitles.Add("Miss");
_listTitles.Add("Mrs");
//_listTitles.Add("Mr");
}
return _listTitles;
}
}
private IList<TB_SETUP_GENDER> _listGENDER;
public IList<TB_SETUP_GENDER> listGENDER
{
get
{
using (DBMain objDBMain = new DBMain())
{
_listGENDER = objDBMain.EntTB_SETUP_GENDER.ToList();
}
return _listGENDER;
}
}
#endregion Properties
#region FormNavigation
private bool isActive;
public override bool IsActive
{
get
{
return this.isActive;
}
set
{
isActive = value;
OnIsActiveChanged();
}
}
protected virtual void OnIsActiveChanged()
{
if (IsActive)
{
_eventAggregator.GetEvent<SubscribeToEvents>().Publish(new Dictionary<string, string>() { { "View", "TB_EMPLOYEE" }, { "FileName", @"Subscribtion to Events" } });
}
else
{
_eventAggregator.GetEvent<UnSubscribeToEvents>().Publish(new Dictionary<string, string>() { { "View", "TB_EMPLOYEE" }, { "FileName", @"UnSubscribtion to Events" } });
}
UnRegisterCommands();
RegisterCommands();
}
public override bool IsNavigationTarget(NavigationContext navigationContext)
{
this.isActive = true;
return this.isActive;
}
public override void OnNavigatedFrom(NavigationContext navigationContext)
{
UnRegisterCommands();
this.isActive = false;
}
public override void OnNavigatedTo(NavigationContext navigationContext)
{
HeaderInfo = "TB_EMPLOYEE";
this.isActive = true;
RegisterCommands();
}
#endregion FormNavigation
}