Start activity whitin android library

Question

I need to start activity within my library. For example, I have a button in main activity and I want to attach to this button a method from library. In this method, I want to start new activity. My problem is I can't pass any info about my app to library, so I can't use context in Intent to start activity. Now I'm trying to do this like that:

public void MethodToInvokeWithinApp()
    {   
        //Because this activity is never started, it haven't
        //built context so I try to achieve this in that way
        OnCreate(new Android.OS.Bundle());//but this throw:
        //Java.Lang.NullPointerException: Attempt to read from field 
        //'java.lang.String 
        //android.content.pm.ActivityInfo.parentActivityName' on a null 
        //object reference
        var intent = new Intent(this, typeof(ActivityInLibrary));
        StartActivity(intent);
        Finish();
    }

Have you any idea how I can achieve this? Is there any way to get context from process?

More info:

This is my class in library and method I want to invoke

[Activity]
public class DroidAuthenticator : MvxActivity, IAuthenticator
{
    private ICallbackManager callbackManager;

    public void FacebookLogin()
    {
        OnCreate(new Android.OS.Bundle());
        var intent = new Intent(this, typeof(FacebookLoginActivity));
        StartActivity(intent);
        Finish();
    }
}

Invoke looks like that:

public class MainViewModel : MvxViewModel
{
    IAuthenticator authenticator;

    private ICommand facebookLoginCommand;
    public ICommand FacebookLoginCommand => 
        facebookLoginCommand = facebookLoginCommand ?? new MvxCommand(FacebookLogin);

    public MainViewModel(IAuthenticator authenticator)
    {
        this.authenticator = authenticator;
    }

    private void FacebookLogin()
    {
        authenticator.FacebookLogin();
    }
}

So as you can see I'm using Xamarin with MvvmCross. In ViewModel I inject IAutheticator with is register on platform side.

Library written by whom? If you. then you can pass the context to lib. — Divakar Murugesh, Feb 27 '18 at 10:07
I'm writing this in cross-platform way so this method must have ability to run without knowledge about app — Golden Panda, Feb 27 '18 at 10:10
actually you need to pass the context for start activity. without that we can't make the screen navigations from the library. so, if you understand what i am trying to say, just pass the context to library when you init the library class and use that context for start activity. that is the easiest way to achieve your goal — Divakar Murugesh, Feb 27 '18 at 10:14
sorry i can't understand...? how can we make necessary info inside??? — Divakar Murugesh, Feb 27 '18 at 10:21
OK. can you please show your library class for better solution??? without that i can't say what is the solution... happy to help you — Divakar Murugesh, Feb 27 '18 at 10:25
why don't you pass the context like this - `authenticator.FacebookLogin(Context);` Otherwise just use the static context. But static context is not the good solution. :) — Divakar Murugesh, Feb 27 '18 at 11:13

Start activity whitin android library

0 Answers0