Java.Lang.NullPointerException exception on FFImageLoading.Cache.ReuseBitmapDrawableCache

[EmilAlipiev]

I am not able to reproduce this issue but i am seeing this exceptions in my appcenter logs. do you have any idea what could be the problem? I am always using latest version of the library and XF 3.6

Android: 8.0.0
Android Build: HUAWEIANE-LX1
Manufacturer: HUAWEI
Model: ANE-LX1
 

Xamarin Exception Stack:
Java.Lang.NullPointerException: key == null || value == null
  at Java.Interop.JniEnvironment+InstanceMethods.CallNonvirtualObjectMethod (Java.Interop.JniObjectReference instance, Java.Interop.JniObjectReference type, Java.Interop.JniMethodInfo method, Java.Interop.JniArgumentValue* args) <0xc6fd0a48 + 0x000d7> in <20c4cde61dc345d982348d283007001a>:0
  at Java.Interop.JniPeerMembers+JniInstanceMethods.InvokeNonvirtualObjectMethod (System.String encodedMember, Java.Interop.IJavaPeerable self, Java.Interop.JniArgumentValue* parameters) <0xc6fa2afc + 0x000af> in <20c4cde61dc345d982348d283007001a>:0
  at Android.Util.LruCache.Put (Java.Lang.Object key, Java.Lang.Object value) <0xc733012c + 0x0013b> in <eb0f7201496a41f28d617743f2ad75d3>:0
  at FFImageLoading.Cache.ByteBoundStrongLruCache`1[TValue].Add (System.String key, TValue value) <0xc431e098 + 0x0008f> in <e726c01889a34a5eaafa84d2b51bb1f0>:0
  at FFImageLoading.Cache.ReuseBitmapDrawableCache`1[TValue].DemoteDisplayedEntryToReusePool (TValue value) <0xc431cac0 + 0x0033f> in <e726c01889a34a5eaafa84d2b51bb1f0>:0
  at FFImageLoading.Cache.ReuseBitmapDrawableCache`1[TValue].OnEntryNoLongerDisplayed (System.Object sender, System.EventArgs args) <0xc431c294 + 0x0009b> in <e726c01889a34a5eaafa84d2b51bb1f0>:0
  at FFImageLoading.Drawables.SelfDisposingBitmapDrawable.SetIsDisplayed (System.Boolean isDisplayed) <0xc4314ad4 + 0x001b7> in <e726c01889a34a5eaafa84d2b51bb1f0>:0
  at FFImageLoading.Drawables.FFBitmapDrawable.SetIsDisplayed (System.Boolean isDisplayed) <0xc4315390 + 0x0001f> in <e726c01889a34a5eaafa84d2b51bb1f0>:0
  at FFImageLoading.Drawables.SelfDisposingBitmapDrawable.SetNoLongerDisplayed () <0xc43149d8 + 0x0007b> in <e726c01889a34a5eaafa84d2b51bb1f0>:0
  at FFImageLoading.Drawables.SelfDisposingBitmapDrawable.Dispose (System.Boolean disposing) <0xc431514c + 0x00007> in <e726c01889a34a5eaafa84d2b51bb1f0>:0
  at Java.Lang.Object.Finalize () <0xc742cd24 + 0x000df> in <eb0f7201496a41f28d617743f2ad75d3>:0
  at java.lang.NullPointerException: key == null || value == null
  at android.util.LruCache.put(LruCache.java:166)

[daniel-luberda]

Hi @EmilAlipiev :)

Somehow image with null key is added to memory cache.

• Do you use any custom keys for image loading?
• Do you use Stream image sources?

[EmilAlipiev]

Hi Daniel,

sorry for late answer. I had ignored this error but recently it occurred again. actually I dont use any custom key or no image streaming. I am mostly using images directly on xaml in listview with remote urls. so they are getting downloaded as user scrolls in the list. it can be that user scrolls very fast and it causes this crash.

[EmilAlipiev]

there is a related report from the same phone I guess. maybe this might give more information

JniEnvironment+InstanceMethods.CallNonvirtualObjectMethod (Java.Interop.JniObjectReference instance, Java.Interop.JniObjectReference type, Java.Interop.JniMethodInfo method, Java.Interop.JniArgumentValue* args)
JniPeerMembers+JniInstanceMethods.InvokeNonvirtualObjectMethod (System.String encodedMember, Java.Interop.IJavaPeerable self, Java.Interop.JniArgumentValue* parameters)
LruCache.Put (Java.Lang.Object key, Java.Lang.Object value)
ByteBoundStrongLruCache`1[TValue].Add (System.String key, TValue value)
ReuseBitmapDrawableCache`1[TValue].DemoteDisplayedEntryToReusePool (TValue value)
ReuseBitmapDrawableCache`1[TValue].OnEntryNoLongerDisplayed (System.Object sender, System.EventArgs args)
SelfDisposingBitmapDrawable.SetIsDisplayed (System.Boolean isDisplayed)
FFBitmapDrawable.SetIsDisplayed (System.Boolean isDisplayed)
SelfDisposingBitmapDrawable.SetNoLongerDisplayed ()
SelfDisposingBitmapDrawable.Dispose (System.Boolean disposing)
Object.Finalize ()

[EmilAlipiev]

I could reproduce this issue but i dont know the exact reason.
This is happening with SVG images. my svg images are all local, not remote. when i load svg images on listview which is on modalpage and while images are loading if i pop the modal page, this crash is happening. it doesnt happen always. So probably there is a state cannot be disposable and when you try to dispose the page.