how to access public Members(variable or method) of MainActivity class in fragment class

Question

i have a Xamarin-Android app in which i used fragments .i want to access public Method of MainActivity in my fragment class.

webview_download+=mWebViewDownload

but this method mWebViewDownload is defined in MainActivity.i cannot access this method from fragment.

i tried to make this method static but this method uses services which can't be accessed without instance. i tried to access through this.mWebViewDownload but the error is mWebViewDownload is not defined in this scope like that. i searched stackoverflow for it most of question suggest getActivity() but this is java related solution but i need c# related solution. i tried to access it through MainActivity.mWebViewDownload but it also gives error that cann't access non-static without object reference like that.please help.fragment class is as follows:

        internal class WebviewFragment : Fragment
        {
            public const string ARG_NUMBER = "number";

            public WebviewFragment()
            {
                // Empty constructor required for fragment subclasses
            }

            public static Fragment NewInstance(int position)
            {

                Fragment fragment = new WebviewFragment();
                Bundle args = new Bundle();
                args.PutInt(WebviewFragment.ARG_NUMBER, position);
                fragment.Arguments = args;
                return fragment;
            }

            public override View OnCreateView(LayoutInflater inflater, ViewGroup container,
                                               Bundle savedInstanceState)
            {
                View rootView = inflater.Inflate(Resource.Layout.fragment_content2, container, false);
                var i = this.Arguments.GetInt(ARG_NUMBER);
                var url = this.Resources.GetStringArray(Resource.Array.weburls_array)[i];

                var title = this.Resources.GetStringArray(Resource.Array.contents_array)[i];
                // show progress bar

                progressBar = (ProgressBar)rootView.FindViewById<ProgressBar>(Resource.Id.progressBar1);
                var web_view = rootView.FindViewById<WebView>(Resource.Id.webview);

                web_view.SetWebViewClient(new HelloWebViewClient());

                web_view.Settings.JavaScriptCanOpenWindowsAutomatically = true;
                web_view.Settings.JavaScriptEnabled = true;
                web_view.Download += Mwebview_Download;// here is error
                //set the custom web client
                web_view.SetWebViewClient(new JavaScriptWebViewClient());

                web_view.LoadUrl(url);


                this.Activity.Title = title;
                return rootView;
            }
        }

here is the mWebView_Download Method in MainActivity class

 // Download
        public void Mwebview_Download(object sender, DownloadEventArgs e)
        {
            var listPermissions = new System.Collections.Generic.List<string>();

            if (CheckSelfPermission(Android.Manifest.Permission.WriteExternalStorage) != Permission.Granted)
            {
                Log.Warn(LOG_TAG, "CheckSelfPermission(WriteExternalStorage) not yet granted - will prompt user for permission");
                listPermissions.Add(Android.Manifest.Permission.WriteExternalStorage);


                // Make the request with the permissions needed...and then check OnRequestPermissionsResult() for the results
                RequestPermissions(listPermissions.ToArray(), PERMISSION_Write_External_Storage);
            }
            else
            {

                var url = e.Url;

                DownloadManager.Request request = new DownloadManager.Request(Android.Net.Uri.Parse(url));

                request.AllowScanningByMediaScanner();
                string filename = System.IO.Path.GetFileName(url);


                request.SetNotificationVisibility(DownloadVisibility.VisibleNotifyCompleted);
                //  request.SetNotificationVisibility(DownloadManager.Request.VisibilityVisibleNotifyCompleted); //Notify client once download is completed!

                request.SetDestinationInExternalPublicDir(Android.OS.Environment.DirectoryDownloads, filename);
                DownloadManager dm = (DownloadManager)GetSystemService("download");
                dm.Enqueue(request);
                Toast.MakeText(ApplicationContext, "Downloading File", ToastLength.Long//To notify the Client that the file is being downloaded
                            ).Show();
            }
        }
       ```

Answer 1

Solutions:

1 .Define a static property in your MainActivity and use it in Fragment, for example:

public class MainActivity : AppCompatActivity
{
    public static MainActivity Instance;
    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        Xamarin.Essentials.Platform.Init(this, savedInstanceState);
        SetContentView(Resource.Layout.activity_main);

        Instance = this;
    }   
    public void test()
    {

    }
}

And then in your fragment, you can access the method by:

MainActivity.Instance.test();

2 .getActivity() method in C# is ((ActivityType)Activity).yourPublicMethod() ; :

 public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        // Use this to return your custom view for this Fragment
        // return inflater.Inflate(Resource.Layout.YourFragment, container, false);

        ((MainActivity)Activity).test();

        return base.OnCreateView(inflater, container, savedInstanceState);
    }