title	description	ms.date
Platform helpers	The Platform class, in the Microsoft.Maui.ApplicationModel, contains helpers for each platform.	03/27/2023

Platform helpers

The static Platform class, in the xref:Microsoft.Maui.ApplicationModel namespace, contains helpers for each platform.

Android

The Platform class contains the following helpers on Android:

Member	Purpose
`ActivityStateChanged`	An event that's raised when any Activity's state changes.
`AppContext`	A property that gets the xref:Android.Content.Context object that represents the current app context.
`CurrentActivity`	A property that gets the current xref:Android.App.Activity object that represents the current activity.
`Intent`	A static class that contains the `ActionAppAction` string, which is the identifier for the xref:Android.Content.Intent used by app actions.
`OnNewIntent`	Pass an xref:Android.Content.Intent from an activity's overridden method, when invoking an app action.
`OnResume`	Pass an xref:Android.App.Activity from an activity's overridden method, when an xref:Android.App.Activity is resumed as part of invoking an app action.
`OnRequestPermissionsResult`	Pass permission request results from an activity's overridden method, for handling internal permission requests.
`WaitForActivityAsync`	Wait for an xref:Android.App.Activity to be created or become active.

The following example shows how to access the current Context or Activity for the running app:

var context = Platform.AppContext;

// Current Activity or null if not initialized or not started.
var activity = Platform.CurrentActivity;

If there's a situation where the xref:Android.App.Activity is needed, but the app hasn't fully started, call the WaitForActivityAsync method:

var activity = await Platform.WaitForActivityAsync();

The Platform class contains the following helper methods on iOS and Mac Catalyst:

Method	Purpose
`ContinueUserActivity`	Informs the app that there's data associated with continuing a task specified as a xref:Foundation.NSUserActivity object, and then returns whether the app continued the activity.
`GetCurrentUIViewController`	Gets the current view controller. This method will return `null` if unable to detect a xref:UIKit.UIViewController.
`OpenUrl`	Opens the specified URI to start an authentication flow.
`PerformActionForShortcutItem`	Invokes the action that corresponds to the chosen `AppAction` by the user.

The following example shows how to retrieve the currently visible xref:UIKit.UIViewController:

var viewController = Platform.GetCurrentUIViewController();

The Platform class contains the following helpers on Windows:

Method	Purpose
`MapServiceToken`	A property that gets or sets the map service API key.
`OnLaunched`	The lifecycle method that's called when the app is launched.
`OnActivated`	Sets the app's new active window.