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Syncfusion.ListView.XForms.Android.ListViewItemRenderer.OnDown exception on 17.3.0.17version

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148451 Oct 20,2019 10:43 PM UTC Jan 3,2020 04:25 AM UTC Xamarin.Forms 14
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Tags: SfListView
Emil
Asked On October 20, 2019 10:43 PM UTC


I am getting below exception on sflistview. I am not sure in which case OnDown is used but i see crashes in my app center logs. can you please check this stack trace below? i am using XF version 4.2.0.848062

Xamarin Exception Stack: System.NullReferenceException: Object reference not set to an instance of an object. at Syncfusion.ListView.XForms.Android.ListViewItemRenderer.OnDown (Android.Views.MotionEvent e) [0x00019] in <da0db635488a4ceb995c19681358c784>:0 at Android.Views.GestureDetector+IOnGestureListenerInvoker.n_OnDown_Landroid_view_MotionEvent_ (System.IntPtr jnienv, System.IntPtr native__this, System.IntPtr native_e) [0x00011] in <266395aeef1642bab2007ca31686faf9>:0 at (wrapper dynamic-method) Android.Runtime.DynamicMethodNameCounter.99(intptr,intptr,intptr) Thread 2: 0 dalvik.system.VMStack.getThreadStackTrace(VMStack.java:-2) 1 java.lang.Thread.getStackTrace(Thread.java:1538) 2 java.lang.Thread.getAllStackTraces(Thread.java:1588) 3 com.microsoft.appcenter.crashes.Crashes.saveUncaughtException(Crashes.java:970) 4 com.microsoft.appcenter.crashes.WrapperSdkExceptionManager.saveWrapperException(WrapperSdkExceptionManager.java:55) 5 md5048335796d6a848447231107a6de4b57.ListViewItemRenderer.n_onDown(ListViewItemRenderer.java:-2) 6 md5048335796d6a848447231107a6de4b57.ListViewItemRenderer.onDown(ListViewItemRenderer.java:87) 7 android.view.GestureDetector.onTouchEvent(GestureDetector.java:619) 8 md5048335796d6a848447231107a6de4b57.ListViewItemRenderer.n_onTouchEvent(ListViewItemRenderer.java:-2) 9 md5048335796d6a848447231107a6de4b57.ListViewItemRenderer.onTouchEvent(ListViewItemRenderer.java:79) 10 android.view.View.dispatchTouchEvent(View.java:13484) 11 android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3216) 12 android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2888) 13 md51558244f76c53b6aeda52c8a337f2c37.VisualElementRenderer_1.n_dispatchTouchEvent(VisualElementRenderer_1.java:-2) 14 md51558244f76c53b6aeda52c8a337f2c37.VisualElementRenderer_1.dispatchTouchEvent(VisualElementRenderer_1.java:65) 15 android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3222) 16 android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2845) 17 md51558244f76c53b6aeda52c8a337f2c37.Platform_DefaultRenderer.n_dispatchTouchEvent(Platform_DefaultRenderer.java:-2) 18 md51558244f76c53b6aeda52c8a337f2c37.Platform_DefaultRenderer.dispatchTouchEvent(Platform_DefaultRenderer.java:55) 19 android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3222) 20 android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2845) 21 android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3222) 22 android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2845) 23 android.widget.HorizontalScrollView.dispatchTouchEvent(HorizontalScrollView.java:539) 24 android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3222) 25 android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2845) 26 android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3222) 27 android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2845) 28 md51558244f76c53b6aeda52c8a337f2c37.VisualElementRenderer_1.n_dispatchTouchEvent(VisualElementRenderer_1.java:-2) 29 md51558244f76c53b6aeda52c8a337f2c37.VisualElementRenderer_1.dispatchTouchEvent(VisualElementRenderer_1.java:65) 30 android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3222) 31 android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2845) 32 md51558244f76c53b6aeda52c8a337f2c37.Platform_DefaultRenderer.n_dispatchTouchEvent(Platform_DefaultRenderer.java:-2) 33 md51558244f76c53b6aeda52c8a337f2c37.Platform_DefaultRenderer.dispatchTouchEvent(Platform_DefaultRenderer.java:55) 34 android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3222) 35 android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2845) 36 md51558244f76c53b6aeda52c8a337f2c37.Platform_DefaultRenderer.n_dispatchTouchEvent(Platform_DefaultRenderer.java:-2) 37 md51558244f76c53b6aeda52c8a337f2c37.Platform_DefaultRenderer.dispatchTouchEvent(Platform_DefaultRenderer.java:55) 38 android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3222) 39 android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2845) 40 md51558244f76c53b6aeda52c8a337f2c37.Platform_DefaultRenderer.n_dispatchTouchEvent(Platform_DefaultRenderer.java:-2) 41 md51558244f76c53b6aeda52c8a337f2c37.Platform_DefaultRenderer.dispatchTouchEvent(Platform_DefaultRenderer.java:55) 42 android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3222) 43 android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2845) 44 android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:3222)

Sangeetha Raju [Syncfusion]
Replied On October 21, 2019 12:24 PM UTC

Hi Emil, 
 
We have checked the reported query from our side with Xamarin Forms version as 4.2.0.848062 and SfListView version as 17.3.0.17. While checking with the reported query we did not face any issues in Android as reported. We have attached the tested sample for your reference. Please find the sample from the follwoing link. 
 
 
Could you please check with the above sample?. We suspect that the issue may occur at particular scenario as existing in yours. So, we recommend you to revert us the issue with reproducible sample or replication procedure to reproduce it which will help us to analyze your query better and provide appropriate solution at our end. 
 
Regards, 
Sangeetha Raju. 


Taras Teslya
Replied On October 25, 2019 09:35 AM UTC

Hi,

I also see same issue

Xamarin Exception Stack: System.NullReferenceException: Object reference not set to an instance of an object at Syncfusion.ListView.XForms.Android.ListViewItemRenderer.OnDown (Android.Views.MotionEvent e) [0x00019] in <47babd519fd9454a85e0bfae52f037f0>:0 at Android.Views.GestureDetector+IOnGestureListenerInvoker.n_OnDown_Landroid_view_MotionEvent_ (System.IntPtr jnienv, System.IntPtr native__this, System.IntPtr native_e) [0x00011] in <7f15356de6644318af3142390ce1e7ae>:0 at (wrapper dynamic-method) Android.Runtime.DynamicMethodNameCounter.102(intptr,intptr,intptr)

I can't reproduce it on my phone, but I see that some users have crashes.
I see such errors with XF 4.2.0.848062 and in  XF 4.3.0.908675.
Previously I had XF 3.6.0.709228, and no issues.

Mageshyadav M [Syncfusion]
Replied On October 28, 2019 03:24 PM UTC

Hi Taras, 
 
We have mentioned earlier in our previous update we unable to reproduce the reported issue in Android as reported at our end.  
 
Could you please check with the above sample in our perivious update?. We suspect that the issue may occur at particular scenario as existing in yours such as machine version. So, we recommend you to revert us the issue with reproducible sample or revert back us with following details. 
  • Device configuration details.
  • Syncfusion control and Xamarin.Forms versions used.
It will be helpful for us to check on it and provide you the solution at the earliest. 
 
Regards 
Gokul Saravanan 


Taras Teslya
Replied On October 30, 2019 09:47 AM UTC

Hi,
I don't have reproducible sample. I see it in AppCenter list of errors.
From AppCenter logs I see that it happens on many pages with different SfListViews.

I started receiving this error after switching to XF 4.2, with 3.6 I didn't have it. After migrating to XF 4.3 I still see error. 
SFListView 17.3.0.17, 17.3.0.19

I could give you information about devices from AppCenter.
Information about devices:





Emil
Replied On October 30, 2019 11:21 AM UTC

yes same for me. i cannot reproduce myself but in appcenter logs many crashes from other users. It apparently crashing with null reference exception for the mentioned function.

Gokul Saravanan [Syncfusion]
Replied On October 30, 2019 01:37 PM UTC

Hi Emil/Taras  
  
Thank you for the update.

We could not able to replicate the reported issue with the shared details from our end.
 To proceed further, please share the following details,  
·        Did you handled any touch gestures for views inside ListView ItemTemplate - If so, please share the code snippets. 
·        Any touch-related codes handled in custom renderers, for SfListView or its child views used in DataTemplate. 
·        Handled any SfListView selection / tap events.

 
Kindly share the details mentioned above, it will be helpful for us to analyze better at our end and find the cause where OnDown() method throws the exception and provide you the solution at the earliest. 
  
Regards 
Gokul Saravanan 


Gnana Priya Namasivayam [Syncfusion]
Replied On October 31, 2019 12:37 PM UTC

Hi Emil/Taras, 
  
  
We have added possible null check based on the provided call stack. We would like to inform that fix will be included in the upcoming 2019 Vol 3 SP1 release which is scheduled to be rolled out on first week of November, 2019. We will appreciate your patience until then.

In the meantime, please share the requested details in the previous update to ensure from our end. 
  
Regards, 
Gnana Priya N 


Taras Teslya
Replied On November 5, 2019 09:58 PM UTC

Hello,
I see we use this gesture control on pages which crash: https://github.com/ScienceSoft-Inc/ViewGestures
We published  today version with controls from 17.3.0.26 update. I will check app center logs after few days, and let you know about your fix.
Anyway we will remove that gesture control from code later.

Taras Teslya
Replied On November 5, 2019 09:59 PM UTC

And thank you for your fix.

Sangeetha Raju [Syncfusion]
Replied On November 6, 2019 06:32 AM UTC

Hi Taras, 
 
Thank you for the update. Please let us know if you require any further assistance. 
 
Regards, 
Sangeetha Raju. 


Emil
Replied On January 1, 2020 03:13 AM UTC

@Taras: are you not seeing this crash any longer? which version did you update last? I am seeing still crashes on 17.3.0.21



Gnana Priya Namasivayam [Syncfusion]
Replied On January 2, 2020 06:53 AM UTC

Hi Emil, 
 
We would like to inform you that we have fixed the reported issue based on call stack and included in sfListView v17.3.0.26. Kindly update SfListView to fixed version to resolve the reported issue. We have also mentioned in our release notes, please find them from below for your reference. 
 
 
Please let  us know if you have any further queries.           
 
Regards, 
Gnana Priya N 


Taras Teslya
Replied On January 2, 2020 12:53 PM UTC

Yes, I could approve that issue is fixed in new version.

Gnana Priya Namasivayam [Syncfusion]
Replied On January 3, 2020 04:25 AM UTC

Hi Emil, 
 
Can you please update SfListview version and confirm us whether the reported issue have been resolved at your end.  
 
Regards, 
Gnana Priya N 


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