Xamarin Droid App啟動時出現NullReferenceException

Question

通過Visual Studio 2015啟動Xamarin Android應用程序時，我面臨NullReferenceException。

在我的主要活動中離開OnCreate（）之后拋出它，但我不知道在哪里以及為什么。 如何找到有關此錯誤的更多信息？

Debug輸出如下：

05-21 20:18:51.643 D/OpenGLRenderer(25574): Use EGL_SWAP_BEHAVIOR_PRESERVED: true
05-21 20:18:51.651 D/Atlas   (25574): Validating map...
Unhandled Exception:

System.NullReferenceException: Object reference not set to an instance of an object

Exception:

System.NullReferenceException: Object reference not set to an instance of an object

05-21 20:19:37.436 D/Mono    (25574): DllImport attempting to load: '/system/lib/liblog.so'.
05-21 20:19:37.436 D/Mono    (25574): DllImport loaded library '/system/lib/liblog.so'.
05-21 20:19:37.436 D/Mono    (25574): DllImport searching in: '/system/lib/liblog.so' ('/system/lib/liblog.so').
05-21 20:19:37.436 D/Mono    (25574): Searching for '__android_log_print'.
05-21 20:19:37.436 D/Mono    (25574): Probing '__android_log_print'.
05-21 20:19:37.437 D/Mono    (25574): Found as '__android_log_print'.
05-21 20:19:37.450 I/MonoDroid(25574): UNHANDLED EXCEPTION:
05-21 20:19:37.454 I/MonoDroid(25574): System.NullReferenceException: Object reference not set to an instance of an object
05-21 20:19:37.454 I/MonoDroid(25574):   at Xamarin.Forms.Platform.Android.KeyboardManager.HideKeyboard (Android.Views.View inputView, Boolean overrideValidation) [0x00000] in C:\BuildAgent3\work\aad494dc9bc9783\Xamarin.Forms.Platform.Android\KeyboardManager.cs:14 
05-21 20:19:37.454 I/MonoDroid(25574):   at Xamarin.Forms.Platform.Android.FormsApplicationActivity.OnPause () [0x00000] in C:\BuildAgent3\work\aad494dc9bc9783\Xamarin.Forms.Platform.Android\FormsApplicationActivity.cs:153 
05-21 20:19:37.455 I/MonoDroid(25574):   at Android.App.Activity.n_OnPause (IntPtr jnienv, IntPtr native__this) [0x00009] in /Users/builder/data/lanes/3236/ee215fc9/source/monodroid/src/Mono.Android/platforms/android-23/src/generated/Android.App.Activity.cs:4046 
05-21 20:19:37.455 I/MonoDroid(25574):   at (wrapper dynamic-method) System.Object:5c198319-5b9a-4152-9518-5aa3ce7cab6e (intptr,intptr)
05-21 20:19:37.476 W/art     (25574): JNI RegisterNativeMethods: attempt to register 0 native methods for md52ce486a14f4bcd95899665e9d932190b.JavaProxyThrowable
An unhandled exception occured.

05-21 20:19:38.791 E/mono    (25574): 
05-21 20:19:38.791 E/mono    (25574): Unhandled Exception:
05-21 20:19:38.791 E/mono    (25574): System.NullReferenceException: Object reference not set to an instance of an object
05-21 20:19:38.791 E/mono    (25574):   at (wrapper dynamic-method) System.Object:5c198319-5b9a-4152-9518-5aa3ce7cab6e (intptr,intptr)
05-21 20:19:38.791 E/mono    (25574):   at (wrapper native-to-managed) System.Object:5c198319-5b9a-4152-9518-5aa3ce7cab6e (intptr,intptr)
05-21 20:19:38.792 E/mono-rt (25574): [ERROR] FATAL UNHANDLED EXCEPTION: System.NullReferenceException: Object reference not set to an instance of an object
05-21 20:19:38.792 E/mono-rt (25574):   at (wrapper dynamic-method) System.Object:5c198319-5b9a-4152-9518-5aa3ce7cab6e (intptr,intptr)
05-21 20:19:38.792 E/mono-rt (25574):   at (wrapper native-to-managed) System.Object:5c198319-5b9a-4152-9518-5aa3ce7cab6e (intptr,intptr)
referenceTable GDEF length=670 1
referenceTable GSUB length=7202 1
referenceTable GPOS length=24560 1

Answer 1

我知道這已經有一段時間了，但也許我可以在將來幫助某人。 當我在應用程序啟動時意外刪除了我的App.Current.Mainpage的啟動時，發生了類似的事情。 愚蠢的錯誤導致無益的錯誤信息。

從我這里了解我的問題所在： https ： //bugzilla.xamarin.com/show_bug.cgi？id = 36287