NGUI创建UIRoot后报NullReferenceException的解决办法

本文参考自 http://forum.china.unity3d.com/thread-1099-1-1.html

使用NGUI版本3.7.5。

在创建了一个UIRoot后，有时会报NullReferenceException的错误,如下图。虽然报错但是不影响运行。

截取部分报错输出是

NullReferenceException: Object reference not set to an instance of an object
UIPanel.get_worldCorners () (at Assets/NGUI/Scripts/UI/UIPanel.cs:623)
UIPanelInspector.OnSceneGUI () (at Assets/NGUI/Scripts/Editor/UIPanelInspector.cs:87)
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at /Users/builduser/buildslave/mono-runtime-and-classlibs/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at

双击错误进入NGUI的UIPanel脚本，会定位到这段代码

if (anchorOffset && mCam == null || mCam.transform.parent != cachedTransform)

将这段代码修改为下面的代码即可修复此错误

if (anchorOffset && (mCam == null || mCam.transform.parent != cachedTransform))