- Passing parameters
- Understanding Prism – Part 2 – Regions
- Introduction to Prism
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- Navigation Overview
Passing parametersNavigating in a Prism application is conceptually different than standard navigation in Xamarin. While Xamarin. Forms navigation relies on a Page class instance to navigate, Prism removes all dependencies on Page types to achieve loosely coupled navigation from within a ViewModel. In Prism, the concept of navigating to a View or navigating to a ViewModel does not exist. Instead, you simply navigate to an experience, or a unique identifier, which represents the target view you wish to navigate to in your application. This means when you request to navigate to the MainPage, you will provide the string "MainPage" as the navigation target. This process uses reflection which introduces a small performance hit. If you would like to avoid this performance hit, you can provide the ViewModel type when registering your Page for navigation. So when we want to navigate to the MainPage, we would provide the "CustomKey" as the navigation target. When writing a Xamarin. Forms apllication, it is common to use a different view for a specific platform. Prism enables you to register different views for different platforms while using the same ViewModel. To do this, simply register your views using the IContainerRegistry. RegisterForNavigationOnPlatform method. Depending on which platform your app is running on, the appropriate view will be provided for the respective platform. Another common scenario when creating a Xamarin. Forms aplication is the need to provide a different view based on the device the app is running on, such as Desktop, Phone, Tablet, etc. Depending on which device your app is running on, the appropriate view will be provided for the respective device. Once your views are registered for navigation, you must use the INavigationService to perform navigation. There is a caveat while injecting the Navigation Service into your ViewModels. The current version of the Prism. Forms library requires that you name the injection parameter precisely as navigationService Otherwise the Navigation Service is unaware of the current View it is used on. This is a limitation of the dependency injection container. Relative navigation will always push pages onto the current navigation stack relative to where you are calling the INavigationService. NavigateAsync method. Absolute navigation will reset the entire navigation stack no matter where you call it, or where you are in the current navigation stack. It is equivalent to Application. Going back to the previous View is as simple calling the INavigationService. GoBackAsync method. However, sometimes you require full contol over whether or not you perform a modal or non-modal navigation. To tell the Prism navigation service how to handle the navigation request, set the useModalNavigation parameter in the INavigationService. NavigateAsync method signature. If you do not want this behavior, and instead wish to force ViewC to be navigated to modally, you must set the useModalNavigation parameter to true. The same approach applies to GoBackAsync. For example, let's assume your navigation stack is rooted with a ContentPage which then has a NavigationPage pushed modally onto the navigation stack. In this case, if you were to call GoBackAsync from ViewA, nothing would happen because you are within the context of a NavigationPage and Prism does not know if you want a non-modal or a modal GoBack operation. Navigation Basics Navigating in a Prism application is conceptually different than standard navigation in Xamarin. Page navigation in Prism is accomplished by using the INavigationService. Important If you do not register your Pages with Prism, navigation will not work.
Understanding Prism – Part 2 – Regions
GitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together. Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community. Already on GitHub? Sign in to your account. Note that the support for the Windows. Frame control is not present, but may be added later on by creating a control that works using a view-first pattern. If required, UI Tests and unit tests may be added to this PR in the same way it is done for the Uno Platform, using simulators on hosted agents for speed of builds. Thanks dansiegel and brianlagunas for the amazing work on PrismLib! Thanks jeromelaban for this amazing PR. There are some extremely different concepts between Prism. Forms and Prism. WPF navigation, but I might suggest taking a peek at the e2e app for Prism. It's a better example of providing some testable surface area with Dialogs, Modules and various Navigation paradigms. I'm also working on migrating the Container specific tests for WPF to be largely shared as part of the removal of the CommonServiceLocator, hopefully that will help give you a baseline for some unit testing. Skip to content. Dismiss Join GitHub today GitHub is home to over 40 million developers working together to host and review code, manage projects, and build software together. Sign up. New issue. Copy link Quote reply. This comment has been minimized. Sign in to view. This was referenced Apr 8, Does Uno support Prism? Uno platform fails in Xamarin.
Introduction to Prism
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