Managing activities in Android

Activities are an integral element of the Android platform. By default your Uno Platform application runs in a single activity, but you might for example spawn a new activity when a user shares content, or picks an image from their device. This article covers Activity management in Uno.

Android documentation links

• Introduction to Activities

• Understand the Activity Lifecycle

Creating/Using Android Activities

At the root of every Android Uno app, lies a BaseActivity class that extends from Android.Support.V7.App.AppCompatActivity which is part of the Android v7 AppCompat Support Library. If you ever need to create a new Activity within your app or within Uno, you must be sure to extend BaseActivity and, if you need to apply a Theme to the activity, ensure that the Theme you set is a Theme.AppCompat theme (or descendant).

Accessing Android main activity events

Uno Platform provides an API to get access to the events/overrides invoked in the main activity (commonly inheriting from UI.Xaml.ApplicationActivity) outside of the activity class.

In order to get access to these events, you can write the following:

using Uno.UI.ViewManagement;

App()
{
    // ...
    ApplicationViewHelper.GetBaseActivityEvents().Create += OnCreateEvent;
    // ...
}

private void OnCreateEvent(Android.OS.Bundle savedInstanceState)
{

}

Note that some events are raised early during the application lifecycle and may need to be registered from the App constructor.