The error in VS Debugger. When I try to add an new item.

12-16 17:13:56.849 I/MonoDroid(30448): UNHANDLED EXCEPTION:12-16 17:13:56.890 I/MonoDroid(30448): System.NullReferenceException: Object reference not set to an instance of an object
An unhandled exception occured.

12-16 17:13:56.890 I/MonoDroid(30448):   at Intersoft.Crosslight.ViewModels.EditableListViewModelBase`1[CrosslightDB.DomainModels.Inventory.Item].OnDataInserted (IEnumerable`1 items) [0x00000] in <filename unknown>:0 
12-16 17:13:56.890 I/MonoDroid(30448):   at Intersoft.Crosslight.ViewModels.EditableListViewModelBase`1[CrosslightDB.DomainModels.Inventory.Item]._OnDataInserted (IEnumerable`1 items) [0x00000] in <filename unknown>:0 
12-16 17:13:56.890 I/MonoDroid(30448):   at Intersoft.Crosslight.EventSubscription`1[System.Collections.Generic.IEnumerable`1[CrosslightDB.DomainModels.Inventory.Item]].InvokeAction (System.Action`1 action, IEnumerable`1 argument) [0x00000] in <filename unknown>:0 
12-16 17:13:56.890 I/MonoDroid(30448):   at Intersoft.Crosslight.EventSubscription`1+a[System.Collections.Generic.IEnumerable`1[CrosslightDB.DomainModels.Inventory.Item]].<Intersoft.Crosslight.IEventSubscription.GetExecutionStrategy>b__0 (System.Object[] arguments) [0x00000] in <filename unknown>:0 
12-16 17:13:56.890 I/MonoDroid(30448):   at Intersoft.Crosslight.DelegateEventBase.InternalPublish (System.Object[] arguments) [0x00000] in <filename unknown>:0 
12-16 17:13:56.890 I/MonoDroid(30448):   at Intersoft.Crosslight.DelegateEvent`1[System.Collections.Generic.IEnumerable`1[CrosslightDB.DomainModels.Inventory.Item]].Publish (IEnumerable`1 payload) [0x00000] in <filename unknown>:0 
12-16 17:13:56.890 I/MonoDroid(30448):   at Intersoft.Crosslight.EventAggregator.Publish[DataInsertedEvent`1,IEnumerable`1] (IEnumerable`1 payload) [0x00000] in <filename unknown>:0 
12-16 17:13:56.890 I/MonoDroid(30448):   at Intersoft.Crosslight.ViewModels.EditorViewModelBase`1[CrosslightDB.DomainModels.Inventory.Item].OnDataInserted (CrosslightDB.DomainModels.Inventory.Item item) [0x00000] in <filename unknown>:0 
12-16 17:13:56.890 I/MonoDroid(30448):   at Intersoft.AppFramework.ViewModels.DataEditorViewModelBase`2+<ExecuteSave>d__0[CrosslightDB.DomainModels.Inventory.Item,CrosslightDB.DomainModels.Inventory.IItemRepository].MoveNext () [0x00000] in <filename unknown>:0 

To enable data synchronization, you need to perform following tasks:

• Create the entity service, entity repository and entity model that has data synchronization metadata
• Configure the data access target url.
• Register the entity repository.
• Add Crosslight SQLIte assembly in your platform-project reference.
• Set the EnableDataSynchronization property in AppSettings to True.
• Register the SynchronizationService and specify the entity types that will take part in synchronization process.

Source: Enabling Data Synchronization

Could you please provide a running sample which replicates the reported problem? I will try to start my investigation using the provided sample.

Hi Yudi,

I put the sample on github. You can download it here as a .zip file.

I removed the appSettings.WebServerUrl, because it only works in my network.

https://github.com/kiborkm/CrosslightDB

Best regards

BR

Sorry for the delay in sending this.

I run the sent sample in my local end and managed to solve the problem by setting Item.ModifiedDate in InitializeNewItem.

protected override void InitializeNewItem(Item item) {
    base.InitializeNewItem(item);

    this.Item = this.Repository.Create();
    this.Item.PurchaseDate = DateTime.Today;
    this.Item.Qty = 1;
    this.Item.ModifiedDate = DateTime.Now;
    this.Item.Category = this.CategoryRepository.GetAll().OrderBy(o => o.Name).FirstOrDefault();

    this.Title = "Add New Item";
}

Hope this help.

ty, this was an failure too :P

It works now. But if I scroll down to the end in the Inventory List, the Debbuger will show me the whole time this line. 

01-02 10:12:42.677 W/View    (10523): requestLayout() improperly called by android.widget.LinearLayout{2b71ff5 V.E..... ......ID 0,0-768,38} during second layout pass: posting in next frame

Looks like infinite loop. Calls whole time the OnDataLoaded method. What does it mean? I also cant delete, edit and mark last 3 items on Android (when I scroll to the end). If I try to change the page, for example: 'I navigate to the about page' , the application will crash.

01-02 10:22:59.769 E/mono    (10523): Parameter name: jobject01-02 10:22:59.769 E/mono    (10523):   at Android.Runtime.JNIEnv.CallNonvirtualVoidMethod (IntPtr jobject, IntPtr jclass, IntPtr jmethod) [0x00010] in /Users/builder/data/lanes/monodroid-mlion-monodroid-4.18-series/5474129a/source/monodroid/src/Mono.Android/src/Runtime/JNIEnv.g.cs:867 01-02 10:22:59.769 E/mono    (10523):   at Android.Widget.BaseAdapter.NotifyDataSetChanged () [0x00058] in /Users/builder/data/lanes/monodroid-mlion-monodroid-4.18-series/5474129a/source/monodroid/src/Mono.Android/platforms/android-14/src/generated/Android.Widget.BaseAdapter.cs:311 
01-02 10:22:59.770 E/mono-rt (10523):   at Java.Lang.Thread+RunnableImplementor.Run () [0x0000b] in /Users/builder/data/lanes/monodroid-mlion-monodroid-4.18-series/54741201-02 10:22:59.769 E/mono    (10523):   at Intersoft.Crosslight.Android.ObservableListAdapter.<>n__FabricatedMethod7 () [0x00000] in <filename unknown>:0 
01-02 10:22:59.769 E/mono    (10523):   at Intersoft.Crosslight.Android.ObservableListAdapter.<NotifyDataSetChanged>b__6 () [0x00000] in <filename unknown>:0 
01-02 10:22:59.769 E/mono    (10523):   at Java.Lang.Thread+RunnableImplementor.Run () [0x0000b] in /Users/builder/data/lanes/monodroid-mlion-monodroid-4.18-series/5474129a/source/monodroid/src/Mono.Android/src/Java.Lang/Thread.cs:36 
01-02 10:22:59.769 E/mono    (10523):   at Java.Lang.IRunnableInvoker.n_Run (IntPtr jnienv, IntPtr native__this) [0x00009] in /Users/builder/data/lanes/monodroid-mlion-monodroid-4.18-series/5474129a/source/monodroid/src/Mono.Android/platforms/android-14/src/generated/Java.Lang.IRunnable.cs:71 
01-02 10:22:59.769 E/mono    (10523):   at (wrapper dynamic-method) object:7b2e84fb-f952-4980-97ed-af389323bbb0 (intptr,intptr)
01-02 10:22:59.770 E/mono-rt (10523): [ERROR] FATAL UNHANDLED EXCEPTION: System.ArgumentException: 'jobject' must not be IntPtr.Zero.

Problem with the bindings? Like here:
Stackoverflow IntPtr.Zero

Best regards

I tried to replicate the reported problem by using the modified sent sample and do the following:

• scroll down to the in the inventory list;
• delete last 3 items in Android;
• edit last 3 items in Android;
• and mark last 3 items in Android.

I have uploaded the modified sample in OneDrive. Please have the uploaded sample evaluated on your end and let me know whether it helps or not.

The incremental loading is the process of loading data in small chunks. Set IncrementalLoadingSize to 20 will load only first 20 items; and new 20 items when user scroll to the end of the list.
Data synchronization requires all data to be loaded. Since you are enabling data synchronization, you should disable the incremental loading feature.

Hope this help.