Xamarin forms app throws a null exception when creating StandardKernel

Question

I created with VS2017 a cross-platform App(Xamarin Forms) with the template set to Blank App, Platform Android, UI Tech Xamarin.Forms, Code Sharing .NET Standard. All builds and runs and displays "Welcome to Xamarin Froms".

I added the Portable.Ninject package to both the .NET standard PCL project and the Android project. Created the following Test class and interface

public class Test : ITest
    {
        public string name { get; set; }
    }



public interface ITest
    {
        string name { get; set; }
    }

A NinjectModule class

   public class modules : NinjectModule
{
    public override void Load()
    {
        Bind<ITest>().To<Test>();
    }
}

and in the class App:Application and added kernel creation in the constructor

public App ()
        {

            InitializeComponent();

            var settings = new NinjectSettings();
            settings.LoadExtensions = false;

            var mods = new modules();
            var kernel = new StandardKernel(mods);

            var test = kernel.Get<ITest>();

            MainPage = new App12.MainPage();
        }

When ran an ArgumentNULLException. Parameter name:path1 occurs at the new StanardKernel( new modules() ).

Any help will be appreciated. I have tried the Ninject Nuget package, creating the StandardKernel in the android project MainActivity:Oncreate, deleting packages, bin and obj folders ... all with the same result

Addition :- Separated the instantiate of modules class the following is watch window. Shouldn't the Binding list have a count of 1 ?

-       mods    {App12.modules} App12.modules
-       base    {Ninject.Modules.NinjectModule} Ninject.Modules.NinjectModule
+       base    {Ninject.Syntax.BindingRoot}    Ninject.Syntax.BindingRoot
+       Bindings    Count = 0   System.Collections.Generic.List<Ninject.Planning.Bindings.IBinding>
        Kernel  (null)  Ninject.IKernel
        Name    "App12.modules" string
+       Non-public members

Added the Settings.LoadExtensions = false as suggested by hichame.jessou, but the ArgumentNullExtension still happens — Big Kevin

Hichame Yessou Hichame Yessou · Accepted Answer · 2018-01-23T20:19:37

You should add a NinjaSettings object with LoadExtensions set to false to the StandardKernel constructor.

public App()
    {
        InitializeComponent();

        var settings = new NinjectSettings(); 
        settings.LoadExtensions = false;
        var kernel = new StandardKernel(settings, new modules());
        var test = kernel.Get<ITest>();

        MainPage = new App12.MainPage();
    }

Xamarin forms app throws a null exception when creating StandardKernel

1 Answers