xamarin.iosmvvmcrossxamarin-linker

Xamarin Linker : Default constructor not found for type Cirrious.CrossCore.IoC.MvxPropertyInjector


With a skeleton project with FirstView from HotTuna package, and with Build linker behavior set to "Link all assemblies", I get the following error:

System.MissingMethodException: Default constructor not found for type Cirrious.CrossCore.IoC.MvxPropertyInjector

Using NuGet package v3.1.1 for all MvvmCross (4 packages)

LinkerPleaseInclude file does have the line [MonoTouch.Foundation.Preserve(AllMembers = true)]

Using the latest stable build:

On PC: Xamarin for VS 1.12.278 Xamarin.iOS 1.12.278

Mac: Xamarin.iOS 7.2.2.2

Of course with Linker behavior of SDK only, it runs fine. Any suggestions anyone?


Solution

  • Solved; So, with the basic project, there were three consecutive errors in the following order:

    System.MissingMethodException: Default constructor not found for type Cirrious.CrossCore.IoC.MvxPropertyInjector
    

    Next error is:

        Cirrious.CrossCore.Exceptions.MvxException: Failed to construct and initialize ViewModel for type {0} from locator MvxDefaultViewModelLocator - check MvxTrace for more information
    

    This one is difficult; Simple fix is to ofcourse to do a --linkskip=portableLibrary, or to crate an instance of the ViewModel somewhere (perhaps in LinkerPleaseInclude.cs); problem with the second approach at-least in my case is, most of my VM doesn't have a parameter less constructor, and obviously using IOC in this case wouldn't help.

    Final Error:

    System.ArgumentNullException: missing source event info in MvxWeakEventSubscription
    Parameter name: sourceEventInfo
    

    Either use --linkskip=System (ugly), or add the following to LinkerPleaseInclude.cs

        public void Include(INotifyPropertyChanged changed)
        {
            changed.PropertyChanged += (sender, e) =>  {
                var test = e.PropertyName;
            };
        }
    

    This was enough for my basic project to run with LinkAllAssemblies, Using LLVM optimizer, and Use SGen collector.

    Hope this will help anyone looking for a solution.