Xamarin shell querypropertyattribute

Starting with Xamarin. Forms 3. In this post I want to discuss the benefits of using Shell over the traditional Page push and pop navigation that you may be accustomed to, as well as the initial steps that you need to perform in order to get Shell working on a new blank app. Keep in mind that at the moment of writing this post, Shell is still in Preview, but is going to be one of the core features that will be fully available for Xamarin Forms 4.

The new Xamarin Forms Shell is a new paradigm for application navigation that greatly reduces the development complexity that you would find with the normal push-pop navigation, especially in scenarios which require flyout menus. Additionally, applications that use Shell will benefit from improvements in rendering speed and reduced memory consumption.

When you use Shell, you define the content and navigation structure of your application inside of a XAML-C class similar to how you define Pages or other views, and based on the way you set that structure you can end up with an app that contains a Flyout menu, each of the items on that menu could be a TabbedPage, each of the tabs in that page could have many ContentPages displayed with a top tab bar. Personally I think such a navigation structure would be too complex, but the beauty here is that Shell allows you to create the navigation that you want.

Take a look at these images to get a good idea about how the navigation can be structured, from the Flyout menu to the individual ContentPages:. The good news is that there is a new template in Visual Studio that can get you started with Shell very quickly, but I think the best way to understand what is happening is to start with a Blank template and setup everything from the ground up.

The first think to do is to make sure that your projects reference a Xamarin Forms package that is 3. Inside of the solution, check the packages and NuGet folders to make sure that the Xamarin Forms version of the package is 3. As I mentioned before, currently the Shell is in Preview, meaning that it is not available by default even by updating the Xamarin Forms package that is referenced in all your projects to version 3.

If you are already using Xamarin Forms 4 or greater you ca skip this step, but if like me, you are using 3. Init call:. Once you have this setup, you can start using the Shell class, so we can create our own subclass that will do exactly what we need it to do.

Immediately, you will have to change the class that your new class inherits from:. Instead of ContentPage, you will now be using a Shell:. Since now the Shell acts as the container for your whole app, you can take advantage of this and do something like using Material design requires additional setup for the entire app by simply setting the Visual property for the Shell to Material directly from this page:.

As you may have realized by the screenshots at the beginning of this post, your navigations can get as complex as you need them to be, but let me show you how you can set a normal ContentPage as the content for the Shell. In the XAML file that you have for the definition of Shell, you can define a single-page application like this:. Notice how I set a local namespace reference so that I could access MainPage. Aside from that, the definition of the content is very straight forward. This is everything required to display that item in the view.For you who still have not heard about Shell yet, it is at least in this first major version, introduces an application foundation or bootstrap consists of Flyout and Tabs components that easily to be set up and provide many properties as modern navigation components.

In addition, Navigation Routing and Deep linking capability that never been this easier to be implemented thanks to Route and its query parameters and the last, Shell Page Search control. All those come with a bunch of overridable methods if you would like to have custom ones and all controls implemented fast renderers pattern.

Flyout and Tabs are 2 top-level navigation components brought by Shell to help you accomplish navigation tickets in your project as shown in the following images below. An application can have both Flyout and Tab bar or only one of them at a time. Followings are overridable methods provided by ShellRenderer class that can be customized and exported from each platform project.

Optimized navigation using Routes enables the user experience to navigate to a specific page without having to follow a set navigation hierarchy. Given the sample visual hierarchy of app navigation:. Additional routes can be explicitly registered for any sort of pages that does not exist in the Shell visual hierarchy.

And then it leaves the rest path including the query parameters as an argument to navigate to the target page. This is also can be used as in-app navigation.

And the target ViewModel can capture the parameter by decorating the ViewModel property with QueryPropertyAttribute which specifies the name of the property that will receive the data, with the second argument specifying the query parameter id.

Note that when you pass the query parameter, the value is being URL encoded so it needs to be decoded before use. Multiple QueryPropertyAttribute objects are also supported in a class. The integrated search functionality in the pages is also provided by Shell application to save development time.

With a search box that can be added to the top of each page, the search query is handled by custom Search Handler that processes the underlying data source and returns the results back to the search box and displays them in a popup list. See you in next article.

This looks great! Thanks for the write-up. Save my name, email, and website in this browser for the next time I comment. This site uses Akismet to reduce spam. Learn how your comment data is processed. Finally, Xamarin team releases a set of features in Xamarin Forms that makes easier and quicker to get started with than before. Common Navigation User Experience Flyout and Tabs are 2 top-level navigation components brought by Shell to help you accomplish navigation tickets in your project as shown in the following images below.

Integrated Search Control with Shell Page The integrated search functionality in the pages is also provided by Shell application to save development time. Next Story How to increase your mobile games performance. Main Menu.Download the sample.

Forms Shell includes a URI-based navigation experience that uses routes to navigate to any page in the application, without having to follow a set navigation hierarchy.

In addition, it also provides the ability to navigate backwards without having to visit all of the pages on the navigation stack. The BackButtonBehaviorCurrentItemand CurrentState properties are backed by BindableProperty objects, which means that these properties can be targets of data bindings. Navigation is performed by invoking the GoToAsync method, from the Shell class. When navigation is about to be performed, a Navigating event is fired, and a Navigated event is fired when navigation completes.

Navigation can still be performed in a Xamarin. Forms Shell application by using the Navigation property.

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For more information, see Hierarchical Navigation. Navigation is performed in a Shell application by specifying a URI to navigate to. Navigation URIs can have three components:. All items in the Shell hierarchy have a route associated with them.

If a route is not set by the developer, the route is generated at runtime. However, generated routes are not guaranteed to be consistent across different application sessions. This example, from the sample application, creates the following route hierarchy, which can be used in programmatic navigation:.

An ArgumentException will be thrown on application startup if a duplicate route is detected. This exception will also be thrown if two or more routes at the same level in the hierarchy share a route name.

Is there any way to pass objects between pages using the Shell Navigation?

In the Shell subclass constructor, or any other location that runs before a route is invoked, additional routes can be explicitly registered for any pages that aren't represented in the Shell visual hierarchy:. This example registers item detail pages, that aren't defined in the Shell subclass, as routes. These pages can then be navigated to using URI-based navigation, from anywhere within the application. The routes for such pages are known as global routes.

Pages whose routes have been registered with the Routing. RegisterRoute method can be deregistered with the Routing. UnRegisterRoute method, if required. This example enables contextual page navigation, where navigating to the details route from the page for the monkeys route displays the MonkeyDetailPage. Similarly, navigating to the details route from the page for the elephants route displays the ElephantDetailPage.

An ArgumentException will be thrown if the Routing. RegisterRoute method attempts to register the same route to two or more different types. To perform navigation, a reference to the Shell subclass must first be obtained. This reference can be obtained by casting the App. MainPage property to a Shell object, or through the Shell. Current property. Navigation can then be performed by calling the GoToAsync method on the Shell object.

This method navigates to a ShellNavigationState and returns a Task that will complete once the navigation animation has completed. When a route from the Shell visual hierarchy is navigated to, a navigation stack isn't created.

However, when a page that's not in the Shell visual hierarchy is navigated to, a navigation stack is created.Forms 4.

The main highlight was the new Xamarin. Forms Shellwhich seeks to reduce the complexity of building mobile apps by providing fundamental app architecture features. Such as a full visual hierarchy, common navigation experience, URI-based routing, and integrated search handling. In this blog, you will see how easy it is to setup the new Xamarin. Forms Shell with different types of navigation schemes and how to navigate to sub-pages.

Shell introduces a simple container for your mobile applications. Rather than wrestling with a combination of MasterDetailPageTabbedPageand NavigationPagejust start your application with a Shell and begin adding pages. Visual Studio provides a new template project for Shell, but you can also quickly add Shell to any application.

To better grasp the simplicity, start with a blank project Blank Forms App. It should look like this:. Shell provides 3 types of common mobile navigation UI: flyout menu, bottom tabs, and top tabs. In the above example, your application will display three menu items including an icon and a label. For more information on how to customize the flyout such as adding a header, creating other menu items, and customizing the look of the menu items with data templates, check out our flyout documentation.

Specify Tab s like this:. Now the application will render three bottom tabs with icons. Because the code above declared a TabBarthe flyout will be hidden by default. When you have content within a Tab that you wish to show via a top tab bar, you can describe additional ShellContent at the same level like this:. Navigation should be simple, easy, natural, fast, and powerful.

By building upon a new paradigm of page management, Shell establishes a foundation for all of that by default use of data templates, routes, and a powerful new syntax for navigation.

All your existing navigation will still work. When adding your ContentPage s to the Shell instance, you should by default use the ContentTemplate property as demonstrated above. This makes sure that Shell can instantiate your pages on demand instead of loading them all up front and slowing your application startup.

Read more about data templates on docs. Shell assigns a route to every element in your Shell, but you should name them as best fits your needs. Each page now has a declared route with which you can target those pages from anywhere in your application, including view models. In the above example, the navigation service will climb the application from your current position until it finds a matching route to execute and then navigate to it using the expected screen transition.

When going from a tab to another tab, the navigation will be an instant cross-fade. What about navigating to pages not included in your Shell? Navigating to relative routes?Since the release of Xamarin Forms 4. Since one of my highest ranking blog posts is how to create a login page with Xamarin Forms. I thought it was time to revisit the topic and look at how to implement a login page using the Shell.

So what is so special about a login page? Well, to state the obvious, the user should only be able to exit it after entering a correct login. Further, the user should not be able to leave the login page, i. And finally once successfully authenticated, the user should not find the login page when navigating back. So let's see how we can capture the user on a page and then ensure that this page is no longer on the navigation stack while using Shell.

So let's get going with the UI flow of a possible login experience. Our app has the following screen flow: All of our pages have to be registered with the Shell. Note that the first ContentPage in the Shell. If the app was not a total fake on the business logic side. It might be using a Token-based flow; this is where one would check if the app still has a valid token and can go directly to the main screen or the user has to log in.

Beautiful load animation, right? When using Shell, you define the kind of navigation on the target page. Well because otherwise all your Android users could just simply press the Android back button and weasel their way out of your carefully crafted login process.

Now let's add a registration page. Here we define the standard push navigation:? We can do this in the code behind of the AppShell. RegisterRoute "registration", typeof RegistrationPage ; Now we can navigate from the login page to the registration page by as follows: Shell. So as soon as the user has logged in, we display the main page of the app. Which is again defined in the AppShell.

So now that we are in the app. Sometimes you will want to present the user with the option to logout. Shell gives us an easy way to define a flyout menu. So a nice place to add our logout is as a new entry in the flyout right? Instead of defining a flyout item, it will be better to use a menu item.

In general think of flyout items as areas of your app and menu items as actions in the menu. The logout is less an area and more an action.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service. The dark mode beta is finally here. Change your preferences any time.

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Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. It is discussed here. For pages to receive data when navigating, the page class must be decorated with a QueryPropertyAttribute.

The first argument - "Name" refers to the name of the property that will be receiving the data. The second argument - "name" refers to the parameter id that will be passed in the query. You can read more in the official documentation. Learn more. Ask Question. Asked 10 months ago. Active 10 months ago. Viewed times. Looking at the Xamarin shell samples I see this: namespace Xaminals. Alan2 Alan2 Is this SearchHandler. I don't think so, I have a feeling this is custom attribute! Active Oldest Votes.

It allows you to pass parameters to a page when using url navigation It is discussed here. Jason Jason When you set [QueryProperty "Name", "name" ] The first argument - "Name" refers to the name of the property that will be receiving the data.

The second argument - "name" refers to the parameter id that will be passed in the query You can read more in the official documentation. Bruno Caceiro Bruno Caceiro 5, 1 1 gold badge 16 16 silver badges 35 35 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook.

Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog.Sometimes we invest too much time building applications with complex navigations, which makes us extend the delivery period of the app and, therefore, the costs to our customers. Forms Shell.

Forms Shell is a container which aims to improve the navigation complexity of our applications. We are going to create a page called AppShell.

When creating the XAML a code-behind of the page was also generated, which, according to our example, should be called AppShell. Here we must inherit from the class Shell :. Once the page is created, we need to add the components that will allow us to make the navigation and design of our app.

This Shell has given us a structure with which we can work in a very easy and practical way! When more than one is added, they are represented in Tabs. Among the components that we need to add to our page, we have the Flyout, which facilitates navigation and design through a menu. Flyout is a drop-down menu that can be accessed through the hamburger icon or by simply sliding your finger from left to right.

Once our pages are built, we need to be able to navigate between them. One of the most interesting parts of Shell is the ease with which it allows us to navigate through routes.

To register a route, we must only add the property Route followed by the name of the route:. The routes added above take the hierarchy of the parent elements, so if we want to visualize in a faster way how the indicated structure will look, we will obtain a result like this:. In the following examples, some scenarios of access to the different routes of our example were indicated:. I want to go to RegisterRoute "monkeydetails", typeof MonkeyDetailPage. Leomaris Reyes is a Software Engineer from the Dominican Republic, with more than 5 years of experience.

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