我在弹出窗口的DataGrid中显示搜索结果，一旦选择了一个项目，关闭弹出窗口并在页面上显示所选项目。这一切都适用于第一次打开和关闭，但是当我尝试重新打开弹出窗口时，我得到一个未处理的异常“在OnPropertyChanged（”IsOpen“）上的”PresentationFramework.dll“中出现类型'System.InvalidOperationException'的未处理异常调用
查看：
<Button x:Name="btSearch" Command="{Binding SearchNoteCommand}">
<Image Source="images/search.jpg"/>
</Button>
<GroupBox x:Name="grpSearchPopup" VerticalAlignment="Top" HorizontalAlignment="Left" Height="51" Width="170" BorderBrush="{x:Null}" BorderThickness="0">
<Popup Name="popSearch" IsOpen="{Binding IsOpen}" Margin="122,89,0,0">
<Grid>
<DataGrid Name="dgSearchResults" AutoGenerateColumns="False" ItemsSource="{Binding Path=CurrentNote.SearchResults}" SelectedItem="{Binding SelectedItem}" AlternatingRowBackground="#FFED676E" AlternationCount="2" Background="{x:Null}" >
<DataGrid.Columns>
<DataGridTextColumn Binding="{Binding NoteID}" Width="25" Header="ID"/>
<DataGridTextColumn Binding="{Binding Note}" Width="100" Header="Note"/>
<DataGridTextColumn Binding="{Binding Date}" Width="70" Header="Date"/>
<DataGridTextColumn Binding="{Binding Time}" Width="60" Header="Time"/>
</DataGrid.Columns>
</DataGrid>
</Grid>
</Popup>
</GroupBox>
视图模型：
private bool _isOpen;
public bool IsOpen
{
get { return _isOpen; }
set
{
if (_isOpen == value) return;
_isOpen = value;
OnPropertyChanged("IsOpen");
}
}
private NoteModel.SearchResult _selectedItem;
public NoteModel.SearchResult SelectedItem
{
get { return _selectedItem; }
set
{
if (value != _selectedItem)
{
_selectedItem = value;
OnPropertyChanged("SelectedItem");
if (_selectedItem != null)
{
noteData.FetchNote(CurrentNote, _selectedItem.NoteID);
OnPropertyChanged("CurrentNote");
//close the popup for search results
IsOpen = false;
}
}
}
}
private ICommand _searchNote;
public ICommand SearchNoteCommand
{
get
{
if (_searchNote == null)
{
_searchNote = new RelayCommand(
p => this.CanSearchNote(),
p => this.SearchNote());
}
return _searchNote;
}
}
private bool CanSearchNote()
{
if (Search != null)
return true;
return false;
}
private void SearchNote()
{
noteData.SearchNotes(CurrentNote, Search);
//open the popup for search
IsOpen = true;
}
此处发生错误：
protected virtual void OnPropertyChanged(string propertyName)
{
this.VerifyPropertyName(propertyName);
if (this.PropertyChanged != null)
{
var e = new PropertyChangedEventArgs(propertyName);
this.PropertyChanged(this, e); <----- error
}
}
NoteData.cs
public bool SearchNotes(NoteModel CurrentNote, string sSearch)
{
//check the open connection
if (ConnectData.OpenConnection() == true)
{
try
{
string SQLSearch = "select note_id, date, time, note from note where date like '%" + sSearch + "%' or time like '%" + sSearch + "%' or note like '%" + sSearch + "%' group by note_id, date, time, note";
//get the phone types for lookups
SqlCommand cmdSearchNotes = new SqlCommand(SQLSearch, ConnectData.connection);
SqlDataReader drSearchResults = cmdSearchNotes.ExecuteReader();
CurrentNote.SearchResults = new List<NoteModel.SearchResult>();
while (drSearchResults.Read())
{
CurrentNote.SearchResults.Add(new NoteModel.SearchResult()
{
NoteID = (int)drSearchResults["note_id"],
Date = drSearchResults["date"].ToString(),
Time = drSearchResults["time"].ToString(),
Note = (string)drSearchResults["note"]
});
}
drSearchResults.Dispose();
cmdSearchNotes.Dispose();
//close Connection
ConnectData.CloseConnection();
return true;
}
catch (SqlException ex)
{
return false;
throw new ApplicationException("Something went wrong with fetching the note search results: ", ex);
}
}
//connection failed
else
{
return false;
}
}
public bool FetchNote(NoteModel CurrentNote, int NoteID)
{
//check the open connection
if (ConnectData.OpenConnection() == true)
{
try
{
string SQLSearch = "select note_id, date, time, note from note where note_id = " + NoteID;
//get the phone types for lookups
SqlCommand cmdFetchNote = new SqlCommand(SQLSearch, ConnectData.connection);
SqlDataReader drFetchNote = cmdFetchNote.ExecuteReader();
while (drFetchNote.Read())
{
CurrentNote.NoteID = (int)drFetchNote["note_id"];
CurrentNote.Date = drFetchNote["date"].ToString();
CurrentNote.Time = drFetchNote["time"].ToString();
CurrentNote.Note = (string)drFetchNote["note"];
CurrentNote.SearchResults = null;
}
drFetchNote.Dispose();
cmdFetchNote.Dispose();
//close Connection
ConnectData.CloseConnection();
return true;
}
catch (SqlException ex)
{
return false;
throw new ApplicationException("Something went wrong with fetching the note: ", ex);
}
}
//connection failed
else
{
return false;
}
}
堆栈追踪：
σε System.Windows.Controls.ItemContainerGenerator.Verify()
σε System.Windows.Controls.VirtualizingStackPanel.MeasureChild(IItemContainerGenerator& generator, IContainItemStorage& itemStorageProvider, IContainItemStorage& parentItemStorageProvider, Object& parentItem, Boolean& hasUniformOrAverageContainerSizeBeenSet, Double& computedUniformOrAverageContainerSize, Double& computedUniformOrAverageContainerPixelSize, Boolean& computedAreContainersUniformlySized, IList& items, Object& item, IList& children, Int32& childIndex, Boolean& visualOrderChanged, Boolean& isHorizontal, Size& childConstraint, Rect& viewport, VirtualizationCacheLength& cacheSize, VirtualizationCacheLengthUnit& cacheUnit, Boolean& foundFirstItemInViewport, Double& firstItemInViewportOffset, Size& stackPixelSize, Size& stackPixelSizeInViewport, Size& stackPixelSizeInCacheBeforeViewport, Size& stackPixelSizeInCacheAfterViewport, Size& stackLogicalSize, Size& stackLogicalSizeInViewport, Size& stackLogicalSizeInCacheBeforeViewport, Size& stackLogicalSizeInCacheAfterViewport, Boolean& mustDisableVirtualization, Boolean isBeforeFirstItem, Boolean isAfterFirstItem, Boolean isAfterLastItem, Boolean skipActualMeasure, Boolean skipGeneration, Boolean& hasBringIntoViewContainerBeenMeasured, Boolean& hasVirtualizingChildren)
σε System.Windows.Controls.VirtualizingStackPanel.MeasureOverrideImpl(Size constraint, Nullable`1& lastPageSafeOffset, List`1& previouslyMeasuredOffsets, Nullable`1& lastPagePixelSize, Boolean remeasure)
σε System.Windows.Controls.VirtualizingStackPanel.MeasureOverride(Size constraint)
σε System.Windows.Controls.Primitives.DataGridRowsPresenter.MeasureOverride(Size constraint)
σε System.Windows.FrameworkElement.MeasureCore(Size availableSize)
σε System.Windows.UIElement.Measure(Size availableSize)
σε System.Windows.ContextLayoutManager.UpdateLayout()
σε System.Windows.UIElement.UpdateLayout()
σε System.Windows.Interop.HwndSource.SetLayoutSize()
σε System.Windows.Interop.HwndSource.set_RootVisualInternal(Visual value)
σε System.Windows.Interop.HwndSource.set_RootVisual(Visual value)
σε System.Windows.Controls.Primitives.Popup.SetRootVisualToPopupRoot()
σε System.Windows.Controls.Primitives.Popup.CreateWindow(Boolean asyncCall)
σε System.Windows.Controls.Primitives.Popup.OnIsOpenChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
σε System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
σε System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e)
σε System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args)
σε System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType)
σε System.Windows.DependencyObject.InvalidateProperty(DependencyProperty dp, Boolean preserveCurrentValue)
σε System.Windows.Data.BindingExpressionBase.Invalidate(Boolean isASubPropertyChange)
σε System.Windows.Data.BindingExpression.TransferValue(Object newValue, Boolean isASubPropertyChange)
σε System.Windows.Data.BindingExpression.ScheduleTransfer(Boolean isASubPropertyChange)
σε MS.Internal.Data.ClrBindingWorker.NewValueAvailable(Boolean dependencySourcesChanged, Boolean initialValue, Boolean isASubPropertyChange)
σε MS.Internal.Data.PropertyPathWorker.UpdateSourceValueState(Int32 k, ICollectionView collectionView, Object newValue, Boolean isASubPropertyChange)
σε MS.Internal.Data.ClrBindingWorker.OnSourcePropertyChanged(Object o, String propName)
σε MS.Internal.Data.PropertyPathWorker.OnPropertyChanged(Object sender, PropertyChangedEventArgs e)
σε System.Windows.WeakEventManager.ListenerList`1.DeliverEvent(Object sender, EventArgs e, Type managerType)
σε System.ComponentModel.PropertyChangedEventManager.OnPropertyChanged(Object sender, PropertyChangedEventArgs args)
σε ObservableObject.OnPropertyChanged(String propertyName) στο C:\Users\treej\Source\Repos\FiloFix\FiloFix\Helper Classes\ObservableObject.cs:γραμμή 24
σε FiloFix.ViewModel.NoteViewModel.set_IsOpen(Boolean value) στο C:\Users\treej\Source\Repos\FiloFix\FiloFix\ViewModel\NoteViewModel.cs:γραμμή 113
σε FiloFix.ViewModel.NoteViewModel.SearchNote() στο C:\Users\treej\Source\Repos\FiloFix\FiloFix\ViewModel\NoteViewModel.cs:γραμμή 50
σε FiloFix.ViewModel.NoteViewModel.<get_SearchNoteCommand>b__8_1(Object p) στο C:\Users\treej\Source\Repos\FiloFix\FiloFix\ViewModel\NoteViewModel.cs:γραμμή 35
σε RelayCommand.Execute(Object parameter) στο C:\Users\treej\Source\Repos\FiloFix\FiloFix\Helper Classes\RelayCommand.cs:γραμμή 28
σε MS.Internal.Commands.CommandHelpers.CriticalExecuteCommandSource(ICommandSource commandSource, Boolean userInitiated)
σε System.Windows.Controls.Primitives.ButtonBase.OnClick()
σε System.Windows.Controls.Button.OnClick()
σε System.Windows.Controls.Primitives.ButtonBase.OnMouseLeftButtonUp(MouseButtonEventArgs e)
σε System.Windows.UIElement.OnMouseLeftButtonUpThunk(Object sender, MouseButtonEventArgs e)
σε System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
σε System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
σε System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
σε System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
σε System.Windows.UIElement.ReRaiseEventAs(DependencyObject sender, RoutedEventArgs args, RoutedEvent newEvent)
σε System.Windows.UIElement.OnMouseUpThunk(Object sender, MouseButtonEventArgs e)
σε System.Windows.Input.MouseButtonEventArgs.InvokeEventHandler(Delegate genericHandler, Object genericTarget)
σε System.Windows.RoutedEventArgs.InvokeHandler(Delegate handler, Object target)
σε System.Windows.RoutedEventHandlerInfo.InvokeHandler(Object target, RoutedEventArgs routedEventArgs)
σε System.Windows.EventRoute.InvokeHandlersImpl(Object source, RoutedEventArgs args, Boolean reRaised)
σε System.Windows.UIElement.RaiseEventImpl(DependencyObject sender, RoutedEventArgs args)
σε System.Windows.UIElement.RaiseTrustedEvent(RoutedEventArgs args)
σε System.Windows.UIElement.RaiseEvent(RoutedEventArgs args, Boolean trusted)
σε System.Windows.Input.InputManager.ProcessStagingArea()
σε System.Windows.Input.InputManager.ProcessInput(InputEventArgs input)
σε System.Windows.Input.InputProviderSite.ReportInput(InputReport inputReport)
σε System.Windows.Interop.HwndMouseInputProvider.ReportInput(IntPtr hwnd, InputMode mode, Int32 timestamp, RawMouseActions actions, Int32 x, Int32 y, Int32 wheel)
σε System.Windows.Interop.HwndMouseInputProvider.FilterMessage(IntPtr hwnd, WindowMessage msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
σε System.Windows.Interop.HwndSource.InputFilterMessage(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
σε MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
σε MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
σε System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
σε System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler)
σε System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
σε MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
σε MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
σε System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
σε System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
σε System.Windows.Application.RunDispa...
有什么想法吗？提前致谢
答案 0 :(得分：1)
尝试以下
public bool SearchNotes(NoteModel CurrentNote, string sSearch)
{
//check the open connection
if (ConnectData.OpenConnection() == true)
{
try
{
string SQLSearch = "select note_id, date, time, note from note where date like '%" + sSearch + "%' or time like '%" + sSearch + "%' or note like '%" + sSearch + "%' group by note_id, date, time, note";
//get the phone types for lookups
SqlCommand cmdSearchNotes = new SqlCommand(SQLSearch, ConnectData.connection);
SqlDataReader drSearchResults = cmdSearchNotes.ExecuteReader();
// CHANGE IS HERE !!!!!!!!!!!!!!!!
var list = new List<NoteModel.SearchResult>();
while (drSearchResults.Read())
{
CurrentNote.SearchResults.Add(new NoteModel.SearchResult()
{
NoteID = (int)drSearchResults["note_id"],
Date = drSearchResults["date"].ToString(),
Time = drSearchResults["time"].ToString(),
Note = (string)drSearchResults["note"]
});
}
// CHANGE IS HERE !!!!!!!!!!!!!!!!
CurrentNote.SearchResults = list;
drSearchResults.Dispose();
cmdSearchNotes.Dispose();
//close Connection
ConnectData.CloseConnection();
return true;
}
catch (SqlException ex)
{
return false;
throw new ApplicationException("Something went wrong with fetching the note search results: ", ex);
}
}
//connection failed
else
{
return false;
}
}
注意我只在列表填满后指定 CurrentNote.SearchResults 。弹出窗口第一次打开时会绑定到列表。下次单击弹出窗口时已经绑定，并且当您调用
时CurrentNote.SearchResults = ...
某些操作发生在WPF中。然后你去改变那个列表的内容，这就是导致错误的原因。