Ouya via Xamarin crash at Game.cs constructor with NullPointException

andrewcarvalho · August 26, 2014, 10:37pm

I’m at my wits end with this one. I’m not an Android expert by a long shot but I’ll try and describe my setup.

My engine (more like a set of reusable tools) and game are in their own libraries so that I can easily build dlls for each platform and move them around using conditional references.

Setting up my game for Ouya deployment, something I haven’t done in a quite long time nor with the latest monogame version, I get a crash as soon as the game launches. It looks like the Java native call (or however it communicates with C#) to invoke the constructor fails when it calls the Game.cs constructor. It steps through my game and my engine classes that extend Game.cs, but when it gets to the base call to Game() is chokes.

I’ve seen that this could be due to having dlls built for the wrong target platform so I rebuilt my projects with no conditional reference and I still have this same issue. I’m thinking this is some weird project set up thing with Xamarin but I’m willing to take and guesses as this point.

Here is my logcat when the game crashes:

I/MonoDroid(10941): UNHANDLED EXCEPTION: Java.Lang.NullPointerException: Exception of type 'Java.Lang.NullPointerException' was thrown.
I/MonoDroid(10941): at Android.Runtime.JNIEnv.CallNonvirtualVoidMethod (intptr,intptr,intptr,Android.Runtime.JValue[]) <0x001ac>
I/MonoDroid(10941): at Android.Runtime.JNIEnv.InvokeConstructor (intptr,string,Android.Runtime.JValue[]) <0x000b3>
I/MonoDroid(10941): at Android.Runtime.JNIEnv.FinishCreateInstance (intptr,string,Android.Runtime.JValue[]) <0x00037>
I/MonoDroid(10941): at Android.Views.SurfaceView..ctor (Android.Content.Context) <0x0018f>
I/MonoDroid(10941): at OpenTK.GameViewBase..ctor (Android.Content.Context) <0x0001b>
I/MonoDroid(10941): at OpenTK.Platform.Android.AndroidGameView..ctor (Android.Content.Context) <0x0008f>
I/MonoDroid(10941): at Microsoft.Xna.Framework.AndroidGameWindow..ctor (Android.Content.Context,Microsoft.Xna.Framework.Game) <0x0001f>
I/MonoDroid(10941): at Microsoft.Xna.Framework.AndroidGamePlatform..ctor (Microsoft.Xna.Framework.Game) <0x00153>
I/MonoDroid(10941): at Microsoft.Xna.Framework.GamePlatform.Create (Microsoft.Xna.Framework.Game) <0x00023>
I/MonoDroid(10941): at Microsoft.Xna.Framework.Game..ctor () <0x00933>
I/MonoDroid(10941): at Platformer.PlatformerGame..ctor () <0x00033>
I/MonoDroid(10941): at KnightAndDamsel.KDGame..ctor () <0x0001b>
I/MonoDroid(10941): at KnightAndDamsel.Ouya.Activity1.OnCreate (Android.OS.Bundle) <0x0002f>
I/MonoDroid(10941): at Android.App.Activity.n_OnCreate_Landroid_os_Bundle_ (intptr,intptr,intptr) <0x0005b>
I/MonoDroid(10941): at (wrapper dynamic-method) object.98b7e707-8838-482f-88e5-6d9b5c1894c8 (intptr,intptr,intptr) <0x00043>
I/MonoDroid(10941):
I/MonoDroid(10941):   --- End of managed exception stack trace ---
I/MonoDroid(10941): java.lang.NullPointerException
I/MonoDroid(10941):     at android.view.ViewConfiguration.get(ViewConfiguration.java:332)
I/MonoDroid(10941):     at android.view.View.<init>(View.java:3236)
I/MonoDroid(10941):     at android.view.SurfaceView.<init>(SurfaceView.java:176)
I/MonoDroid(10941):     at opentk.GameViewBase.<init>(GameViewBase.java:19)
I/MonoDroid(10941):     at opentk.platform.android.AndroidGameView.<init>(AndroidGameView.java:23)
I/MonoDroid(10941):     at microsoft.xna.framework.AndroidGameWindow.<init>(AndroidGameWindow.java:29)
I/MonoDroid(10941):     at knightanddamsel.ouya.Activity1.n_onCreate(Native Method)
I/MonoDroid(10941):     at knightanddamsel.ouya.Activity1.onCreate(Activity1.java:28)
I/MonoDroid(10941):     at android.app.Activity.performCreate(Activity.java:5063)
I/MonoDroid(10941):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1079)
I/MonoDroid(10941):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2023)
I/MonoDroid(10941):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2084)
I/MonoDroid(10941):     at android.app.ActivityThread.access$600(ActivityThread.java:130)
I/MonoDroid(10941):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1195)
I/MonoDroid(10941):     at android.os.Handler.dispatchMessage(Handler.java:99)
I/MonoDroid(10941):     at android.os.Looper.loop(Looper.java:137)
I/MonoDroid(10941):     at android.app.ActivityThread.main(ActivityThread.java:4745)
I/MonoDroid(10941):     at java.lang.reflect.Method.invokeNative(Native Method)
I/MonoDroid(10941):     at java.lang.reflect.Method.invoke(Method.java:511)
I/MonoDroid(10941):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:786)
I/MonoDroid(10941):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
I/MonoDroid(10941):     at dalvik.system.NativeStart.main(Native Method)
E/mono    (10941):
E/mono    (10941): Unhandled Exception:
E/mono    (10941): Java.Lang.NullPointerException: Exception of type 'Java.Lang.NullPointerException' was thrown.
E/mono    (10941): at Android.Runtime.JNIEnv.CallNonvirtualVoidMethod (intptr,intptr,intptr,Android.Runtime.JValue[]) <0x001ac>
E/mono    (10941): at Android.Runtime.JNIEnv.InvokeConstructor (intptr,string,Android.Runtime.JValue[]) <0x000b3>
E/mono    (10941): at Android.Runtime.JNIEnv.FinishCreateInstance (intptr,string,Android.Runtime.JValue[]) <0x00037>
E/mono    (10941): at Android.Views.SurfaceView..ctor (Android.Content.Context)<0x0018f>
E/mono    (10941): at OpenTK.GameViewBase..ctor (Android.Content.Context) <0x0001b>
E/mono    (10941): at OpenTK.Platform.Android.AndroidGameView..ctor (Android.Content.Context) <0x0008f>
E/mono    (10941): at Microsoft.Xna.Framework.AndroidGameWindow..ctor (Android.Content.Context,Microsoft.Xna.Framework.Game) <0x0001f>
E/mono    (10941): at Microsoft.Xna.Framework.AndroidGamePlatform..ctor (Microsoft.Xna.Framework.Game) <0x00153>
E/mono    (10941): at Microsoft.Xna.Framework.GamePlatform.Create (Microsoft.Xna.Framework.Game) <0x00023>
E/mono    (10941): at Microsoft.Xna.Framework.Game..ctor () <0x00933>
E/mono    (10941): at Platformer.PlatformerGame..ctor
E/mono-rt (10941): [ERROR] FATAL UNHANDLED EXCEPTION: Java.Lang.NullPointerException: Exception of type 'Java.Lang.NullPointerException' was thrown.
E/mono-rt (10941): at Android.Runtime.JNIEnv.CallNonvirtualVoidMethod (intptr,intptr,intptr,Android.Runtime.JValue[]) <0x001ac>
E/mono-rt (10941): at Android.Runtime.JNIEnv.InvokeConstructor (intptr,string,Android.Runtime.JValue[]) <0x000b3>
E/mono-rt (10941): at Android.Runtime.JNIEnv.FinishCreateInstance (intptr,string,Android.Runtime.JValue[]) <0x00037>
E/mono-rt (10941): at Android.Views.SurfaceView..ctor (Android.Content.Context)<0x0018f>
E/mono-rt (10941): at OpenTK.GameViewBase..ctor (Android.Content.Context) <0x0001b>
E/mono-rt (10941): at OpenTK.Platform.Android.AndroidGameView..ctor (Android.Content.Context) <0x0008f>
E/mono-rt (10941): at Microsoft.Xna.Framework.AndroidGameWindow..ctor (Android.Content.Context,Microsoft.Xna.Framework.Game) <0x0001f>
E/mono-rt (10941): at Microsoft.Xna.Framework.AndroidGamePlatform..ctor (Microsoft.Xna.Framework.Game) <0x00153>
E/mono-rt (10941): at Microsoft.Xna.Framework.GamePlatform.Create (Microsoft.Xna.Framework.Game) <0x00023>
E/mono-rt (10941): at Microsoft.Xna.Framework.Game..ctor () <0x00933>
E/mono-rt (10941): at Platformer.PlatforD/Zygote  (  108): Process 10941 exited cleanly (1)

andrewcarvalho · August 27, 2014, 4:50pm

I’ve just tested with an empty project and I’m getting the same error, so it’s definitely something weird with how MonoGame is interfacing with the latest Xamarin. Again, my knowledge in this area is pretty limited so maybe I’m missing something.

If anyone could confirm that creating a blank MonoGame Ouya project does or doesn’t successfully launch, that would be a big help.

EDIT:

When all else fails build absolutely everything from source. Pulling the latest ouya-csharp and having monogame point at it gets the empty project to successfully launch. Going to attempt getting the original project up and running now.

mrhelmut · August 28, 2014, 9:06pm

Depending on the version of Monogame you are using and the Xamarin Studio mpack add-in, there may be a mismatch between android project templates and recent changes regarding how Monogame interfaces with android Activities.

Here is what our AndroidGameActivity class looks like (working with post-3.2 Monogame source code):

[Activity (Label = "Game1", 

        MainLauncher = true,

        Icon = "@drawable/icon",

        Theme = "@style/Theme.Splash",

        AlwaysRetainTaskState = true,

        LaunchMode = Android.Content.PM.LaunchMode.SingleInstance,

        ScreenOrientation = ScreenOrientation.SensorLandscape,

        ConfigurationChanges = Android.Content.PM.ConfigChanges.Orientation |

        Android.Content.PM.ConfigChanges.KeyboardHidden |

        Android.Content.PM.ConfigChanges.Keyboard |

        ConfigChanges.ScreenSize)]

    #if OUYA

    [IntentFilter (new[] { Intent.ActionMain },

        Categories = new[] {Intent.CategoryLauncher, OuyaIntent.CategoryGame})]

    #endif

    public class Game1Activity : AndroidGameActivity

    {

        protected override void OnCreate (Bundle bundle)

        {

            base.OnCreate (bundle);



            #if !OUYA

            // Disable screen timeout

            this.Window.SetFlags(WindowManagerFlags.KeepScreenOn, WindowManagerFlags.KeepScreenOn);

            #endif



            // Create our OpenGL view, and display it

            Game1 game = new Game1 ();

            SetContentView ((View)game.Services.GetService(typeof(View)));

            game.Run ();

        }

        

    }