search

canton7 / Stylet

A very lightweight but powerful ViewModel-First MVVM framework for WPF for .NET Framework and .NET Core, inspired by Caliburn.Micro.
MIT License
981 stars 143 forks source link

NRE in design mode with MahApps HamburgerMenu control #302

Open canton7 opened 2 years ago

canton7 commented 2 years ago

Discussed in https://github.com/canton7/Stylet/discussions/289

Originally posted by **sm-g** October 1, 2021 ``` Object reference not set to an instance of an object. at Stylet.Xaml.View.<>c.<.cctor>b__10_0(DependencyObject d, DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.FrameworkElement.OnPropertyChanged(DependencyPropertyChangedEventArgs e) at System.Windows.DependencyObject.NotifyPropertyChange(DependencyPropertyChangedEventArgs args) at System.Windows.DependencyObject.UpdateEffectiveValue(EntryIndex entryIndex, DependencyProperty dp, PropertyMetadata metadata, EffectiveValueEntry oldEntry, EffectiveValueEntry& newEntry, Boolean coerceWithDeferredReference, Boolean coerceWithCurrentValue, OperationType operationType) at System.Windows.DependencyObject.InvalidateProperty(DependencyProperty dp, Boolean preserveCurrentValue) at System.Windows.DependencyObject.InvalidateProperty(DependencyProperty dp) at System.Windows.Data.BindingExpressionBase.Invalidate(Boolean isASubPropertyChange) at System.Windows.Data.BindingExpression.TransferValue(Object newValue, Boolean isASubPropertyChange) at System.Windows.Data.BindingExpression.Activate(Object item) at System.Windows.Data.BindingExpression.AttachToContext(AttachAttempt attempt) at System.Windows.Data.BindingExpression.MS.Internal.Data.IDataBindEngineClient.AttachToContext(Boolean lastChance) at MS.Internal.Data.DataBindEngine.Task.Run(Boolean lastChance) at MS.Internal.Data.DataBindEngine.Run(Object arg) at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs) at System.Windows.Threading.ExceptionWrapper.TryCatchWhen(Object source, Delegate callback, Object args, Int32 numArgs, Delegate catchHandler) ``` But everything work in runtime. Can I solve this issue? (Hope this condensed xaml still reproduces the issue) ``` ```