DroidInjector

Simple injection tool for Xamarin.Android inspired by Cheeseknife and Butterknife. Check out speed comparsion

Install

Install Nuget package

Usage

[Activity(Label = "Sample", MainLauncher = true, Icon = "@mipmap/icon")]
public class MainActivity : Activity
{
    [View] private TextView _login;
    [View] private TextView _password;
    [View] private TextView _tenant;
    [View] private View _blockInput;
    [View] private Button _enterButton;
    [View] private Button _contactUs;
    [View] private TextInputLayout _tenantInputLayout;
    [View] private TextInputLayout _emailInputLayout;
    [View] private TextInputLayout _passwordInputLayout;
    [View] private Button _logsSecretButton;

    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);

        // Set our view from the "main" layout resource
        SetContentView(Resource.Layout.main);

        Injector.InjectViews(); // Will inject views

        //... do something with views
    }
}

In Fragment:

public class MainFragment : Fragment
{
    [View] private TextView _login;
    [View] private TextView _password;
    [View] private TextView _tenant;
    [View] private View _blockInput;
    [View] private Button _enterButton;
    [View] private Button _contactUs;
    [View] private TextInputLayout _tenantInputLayout;
    [View] private TextInputLayout _emailInputLayout;
    [View] private TextInputLayout _passwordInputLayout;
    [View] private Button _logsSecretButton;

    public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
    {
        var view = inflater.Inflate(Resource.Layout.main, container, false);
        
        Injector.InjectViews(view); // Will inject views

        return view;
    }
}

Fields and properties marked with View will be resolved at runtime.

Calling method InjectViews() starts resolving views.

View attribute

There are serveral ways to use [View] attribute:

// Injector will resolve view with Resource.Id.myButton id
[View] private Button _myButton; 

// If allowMissing false - will throw exception when FindViewById returns null
// If allowMissing true - will ignore when FindViewById returns null
[View(allowMissing:true)] private Button _myButton; 

// Injector will resolve view with Resource.Id.myAwesomeButton id
[View(Resource.Id.myAwesomeButton)] private Button _myAnotherButton;

// Injector will resolve view with Resource.Id.myAwesomeButton id
[View("myAwesomeButton")] private Button _myAnotherButton;

In android class library project you can use only [View] with id specified as string or empty [View] attribute due to in android class library Resource.Id values is not consts, but static int. You can't specify not const argument in attribute.

Menu items injection

Injector can find menu items from Menu. You must mark field or property with MenuItem attribute.

[MenuItem(Resource.Id.action_add)] private IMenuItem _addMenuItem 

To resolve marked field call Injector.InjectMenuItems() with menu argument:

public override bool OnCreateOptionsMenu(IMenu menu)
{
    MenuInflater.Inflate(Resource.Menu.main, menu);
    
    Injector.InjectMenuItems(menu);

    return base.OnCreateOptionsMenu(menu);
}

View events injection [Deprecated. It will be removed in next release]

You can mark methods to subscribe to view event like that:

[ViewEvent(Resource.Id.myEditText, typeof(EditText), nameof(EditText.TextChanged))]
private void CustomClick(object sender, EventArgs args)
{
    Toast.MakeText(this, "CustomClick", ToastLength.Short).Show();
}

Method signature must be same as event delegate signature, or you get InjectorException.

To invoke subscription just call Injector.BindViewActions()

If you have any questions feel free to PM me or open issue.