Can't access private setter using Reflection

I've upgraded our project to 2017.1 and everything seems to be working fine except that I know get this error when I try to place an object from our library.

Spoiler: The error

ArgumentException: Set Method not found for 'AutoDisembark'
System.Reflection.MonoProperty.SetValue (System.Object obj, System.Object value, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] index, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoProperty.cs:433)
XmlHelper.SetObjectValue (System.Reflection.PropertyInfo _cPropInfo, System.Object _cObject, System.Object _cValue, System.Object[] _cIndex) (at Assets/Logic/PlatformPending/Serialization/XmlHelper.cs:1875)
XmlHelper.DeserializeCreateProperty (System.Object _cObject, XmlHelper+AllPropertyInfo _cPropInfo, System.Xml.XmlElement _cElement, System.Type _tAttributeType, ConfigVersion _cStartingVersion, ConfigVersion _cStartingProductBase) (at Assets/Logic/PlatformPending/Serialization/XmlHelper.cs:687)
XmlHelper.DeserializeCreate (IHasSaveProperties _cObject, System.Xml.XmlElement _cElement, System.Type _tAttributeType, ConfigVersion _cStartingVersion, ConfigVersion _cStartingProductBase) (at Assets/Logic/PlatformPending/Serialization/XmlHelper.cs:646)
XVR.RM.Entities.Location.DeserializeCreate (System.Xml.XmlElement _cElement, System.Type _tAttributeType, ConfigVersion _cStartingVersion, ConfigVersion _cStartingProductBase) (at Assets/Logic/Product/DataEntities/Locations/Location.cs:827)
XVR.RM.Modules.TemplateModule+<DeserializeLocation>c__AnonStorey5.<>m__0 (XVR.RM.Entities.Location _cLocation) (at Assets/Logic/Product/Modules/TemplateModule/TemplateModule.cs:1018)
XVR.RM.Modules.LocationModule.AssembleLocation (XVREventInfo _cEventInfo, System.Type _cType, XVR.RM.Modules.LocationModule+PreAssembledDelegate _cDelegate, System.String _sName, System.String _sImagePath, System.String _sIconPath, XVR.Spatial.MapPoint _cMapPoint, System.Guid _cGUID, System.Boolean _bIsGenerated) (at Assets/Logic/Product/Modules/LocationModule/LocationModule.cs:377)
XVR.RM.Modules.TemplateModule.DeserializeLocation (XVREventInfo _cEventInfo, System.Xml.XmlElement _cLocationElement, System.Type _tAttributeType) (at Assets/Logic/Product/Modules/TemplateModule/TemplateModule.cs:1014)
XVR.RM.Modules.TemplateModule.CreateLocationTemplate (XVREventInfo _cEventInfo, XVR.RM.LocationTemplateXmlRoot _cTemplate, System.Boolean _bIsGenerated) (at Assets/Logic/Product/Modules/TemplateModule/TemplateModule.cs:972)
XVR.RM.Modules.TemplateModule.AssembleLocationTemplate (XVREventInfo _cEventInfo, XVR.RM.LocationTemplateXmlRoot _cTemplate, System.Boolean _bIsGenerated) (at Assets/Logic/Product/Modules/TemplateModule/TemplateModule.cs:955)
XVR.RM.Modules.PlacementModule.PlaceLocationTemplate (XVREventInfo _cEventInfo, XVR.RM.LocationTemplateXmlRoot _cTemplate, UnityEngine.Vector2 _vPositionToPlace, System.Boolean _bIsGenerated) (at Assets/Logic/Product/Modules/PlacementModule/PlacementModule.cs:310)
XVR.RM.GUI.LocationLibraryGUI+<UpdateGUI>c__AnonStorey0.<>m__1 (XVR.GUI.Controls.DragDropButton btn, UnityEngine.Vector2 pos) (at Assets/Logic/Product/Modules/LocationModule/GUI/LocationLibraryGUI.cs:198)
XVR.GUI.Controls.DragDropButton.DragDropButton_OnMouseDragEnd (XVR.GUI.GUIComponent _cComponent, UnityEngine.EventSystems.PointerEventData _cEventData) (at Assets/Logic/Platform/GUI/GUICore/Controls/DragDropButton.cs:112)
XVR.GUI.GUIComponent.OnMouseDragEndCallback (UnityEngine.EventSystems.PointerEventData _cEventData) (at Assets/Logic/Platform/GUI/GUICore/GUIComponent.cs:605)
XVR.GUI.GUIOnMouseDragEnd.OnEndDrag (UnityEngine.EventSystems.PointerEventData eventData) (at Assets/Logic/Platform/GUI/GUICore/Events/GUIOnMouseDragEnd.cs:16)
UnityEngine.EventSystems.ExecuteEvents.Execute (UnityEngine.EventSystems.IEndDragHandler handler, UnityEngine.EventSystems.BaseEventData eventData) (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/EventSystem/ExecuteEvents.cs:78)
UnityEngine.EventSystems.ExecuteEvents.Execute[T] (UnityEngine.GameObject target, UnityEngine.EventSystems.BaseEventData eventData, UnityEngine.EventSystems.ExecuteEvents+EventFunction`1[T1] functor) (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/EventSystem/ExecuteEvents.cs:261)
UnityEngine.EventSystems.EventSystem:Update()

It appears that SetValue can no longer find the private setter. I've tried different BindingFlags and different ways of getting the method (see below), but none of them seem to work.

The property I'm trying to access:

Code (CSharp):

1.  
2. public bool AutoDisembark
3. {
4.     get { return m_bAutoDisembark; }
5.     private set
6.     {
7.          AutoDisembarkSet(value);
8.     }
9. }
10.  

Attempts to access it:

Code (CSharp):

1.  
2. var setterMethod = _cPropInfo.GetSetMethod(true);
3. if (setterMethod != null)
4.      setterMethod.Invoke(_cObject, new[] { value });
5.  
6. _cPropInfo.SetValue(_cObject, value, BindingFlags.NonPublic | BindingFlags.Instance| BindingFlags.InvokeMethod | BindingFlags.SetProperty, null, _cIndex, null);
7.  

Am I missing something or have I found a bug?

 

Ah yes, sorry forgot to add this only happens when I switch to .NET 4.6.

 

Okay, I'll make a new test project and submit a bug report.

 

Turns out to be due to the private setter being in an inherited class. I've submitted a bug report, but perhaps this is an intentional change in the behaviour of .NET? I've had a hard time finding documentation on the changes in the .NET framework from the version we were on to 4.6.

 

Could you show an example? I was curious to reproduce the bug but failed to reproduce the "private setter being in an inherited class".

 

Something like this?

Code (CSharp):

1. public class Derived : Base { }
2.  
3. public class Base
4. {
5.        public bool AutoDisembark { get; private set; }
6. }

Code (CSharp):

1. var instance = new Derived();
2. var property = typeof(Derived).GetProperty("AutoDisembark", BindingFlags.Public | BindingFlags.Instance);
3.  
4. // method 1
5. property.SetValue(instance, true);
6.  
7. // method 2
8. var setter = property.GetSetMethod(true);
9. setter.Invoke(instance, new object[] { true });

 

I suspect that perhaps BindingFlags.FlattenHierarchy is necessary.

 

This code fails for me, but ONLY when I'm using the .NET 4.6 framework. Which is why I thought it might be a bug, but apparently .NET has just changed the rules for accessing inherited properties since 2.0

Code (CSharp):

1.  
2.  
3. public class Reflection : MonoBehaviour
4. {
5.     private ClassWithProperties m_cClassWithProperties;
6.  
7.     // Use this for initialization
8.     void Start()
9.     {
10.         m_cClassWithProperties = new ClassWithProperties();
11.     }
12.  
13.     // Update is called once per frame
14.     void Update()
15.     {
16.         Debug.Log("Before " + m_cClassWithProperties.APropertyWithPrivateSetter);
17.         PropertyInfo info = typeof(ClassWithProperties).GetProperty(nameof(ClassWithProperties.APropertyWithPrivateSetter));
18.         info.SetValue(m_cClassWithProperties, true);
19.  
20.         Debug.Log("After " + m_cClassWithProperties.APropertyWithPrivateSetter);
21.     }
22. }
23.  
24.  
25. public class BaseClassWithProperties
26. {
27.     private bool m_bAProperty;
28.  
29.     public bool APropertyWithPrivateSetter
30.     {
31.         get { return m_bAProperty; }
32.         private set
33.         {
34.             m_bAProperty = value;
35.         }
36.     }
37. }
38.  
39. public class ClassWithProperties : BaseClassWithProperties
40. {
41.  
42. }
43.  

 

From MSDN:

I don't think this is the BindingFlag I'm looking for.

 

This one works in Net 4.6:

Code (CSharp):

1. var property = typeof(Derived).GetProperty("AutoDisembark", BindingFlags.Public | BindingFlags.Instance);
2. property = property.DeclaringType().GetProperty(property.Name);

 

Thanks that does indeed work for this particular property.