Error on quitting Android application

[AGB]

When calling Application.Quit(), always getting:

INFO/Unity(14020): NullReferenceException
        at UnityEngine.Component.get_gameObject () [0x00000] in <filename unknown>:0
        at UIDrawCall.Destroy (.UIDrawCall dc) [0x00000] in <filename unknown>:0
        at UIPanel.OnDisable () [0x00000] in <filename unknown>:0
        (Filename:  Line: -1)
INFO/Unity(14020): NullReferenceException
        at UnityEngine.Component.get_gameObject () [0x00000] in <filename unknown>:0
        at UIDrawCall.Destroy (.UIDrawCall dc) [0x00000] in <filename unknown>:0
        at UIPanel.OnDisable () [0x00000] in <filename unknown>:0
        (Filename:  Line: -1)


Is there any workaround? Never got this in Editor.

[ArenMook]

Can't say I've seen that one. It looks like your draw calls get destroyed before the panel for some curious reason.

Change UIPanel.OnDisable to this:

1. protected override void OnDisable ()
2.         {
3.                 for (int i = 0; i < drawCalls.size; ++i)
4.                 {
5.                         UIDrawCall dc = drawCalls.buffer[i];
6.                         if (dc != null) UIDrawCall.Destroy(dc);
7.                 }
8.                 drawCalls.Clear();
9.                 list.Remove(this);
10.                
11.                 if (list.size == 0)
12.                 {
13.                         UIDrawCall.ReleaseAll();
14.                         mUpdateFrame = -1;
15.                 }
16.                 base.OnDisable();
17.         }

[AGB]

Does not help. It seems, that drawCall instance exists, but its gameobject is already terminated..

[adb]

I'm having what I guess is the same issue, but on Windows Phone 8. It happens when the application Quits, every single time. Here is the exception thrown. It appears to be internal to Unity when resolving dc.gameObject in Destroy().

First-chance exception at 0x77C81ECF in TaskHost.exe: Microsoft C++ exception: Platform::NullReferenceException ^ at memory location 0x0416F4F8.

Exception: External component has thrown an exception.
Type: System.Runtime.InteropServices.SEHException
Module: UnityEngineProxy
InnerException: <No Data>
AdditionalInfo:Invoking UIPanel::OnDisable method with argument count: 0
   at UnityEngineProxy.InternalCalls.Component_CUSTOM_InternalGetGameObject(Object self)
   at UnityEngine.Component.get_gameObject()
   at UIDrawCall.Destroy(UIDrawCall dc)
   at UIPanel.OnDisable()
   at lambda_method(Closure , Object , Object[] , Int32 )
   at WinRTBridge.MethodTools.InvokeMethod(Object instance, Int32 methodIndex, Object[] args)

[ArenMook]

Sounds like some bug in Unity I need to make a work-around for. Try changing UIDrawCall.Destroy to this:

1.         static public void Destroy (UIDrawCall dc)
2.         {
3.                 if (dc)
4.                 {
5.                         if (Application.isPlaying)
6.                         {
7.                                 if (mActiveList.Remove(dc))
8.                                 {
9.                                         NGUITools.SetActive(dc.gameObject, false);
10.                                         mInactiveList.Add(dc);
11.                                 }
12.                         }
13.                         else
14.                         {
15.                                 mActiveList.Remove(dc);
16.                                 NGUITools.DestroyImmediate(dc.gameObject);
17.                         }
18.                 }
19.         }

If that doesn't work, try adding a try/catch block around the whole thing.

[breakmachine]

Shouldn't it be if (dc!=null) or does if (dc) work in C# aswell?

[ArenMook]

if (unity object) checks not only the null, but also if the object is in the queue to be destroyed.

[breakmachine]

Your learn something new every day