Tabbed page load only the selected page rather than as a whole - xamarin

So I have a tabbedpage with 5 pages, Now when I navigate to the page where there is the tabbed page it loads all of the 5 pages that's why it's loading for so long. Is there a way to load only the open page rather than loading all of them

Per the Xamarin docs: The TabbedPage does not support UI
virtualization. Therefore, performance may be affected if the
TabbedPage contains too many child elements. So it really depends upon
how you are constructing your pages and if you are using page swiping
and off screen caching (on Android it is using a native ViewPager)

Related

Xamarin tabbed page causing memory leak

My Xamarin forms application has a login page, upon login it shows a tabbed page as the main page with 3 tab pages(navigation page). Each tab page has collection views and other controls. When we logout we set - App.Current.MainPage = LoginPage to show the login page.
Everything works fine. While running xamarin profiler we noticed that the tabbed page and it's children are still in memory. If I login 3 times, I can see 3 instances of the main tab page and each instance has 3 tab children.
Before we logout, we dispose off all the events,timers etc, but the pages are still in memory. I tried to do a PopAsync() but since it's tabbed page it threw an exception. Can anyone please tell me how to remove the tabbed page and it's children from memory?

Static view above Shell Bottom Tabbar in Xamarin Forms

I'm using Shell in my Xamarin Forms app together with a bottom tabbar and no flyout menu.
Is it somehow possible to have a static view/control between the content page and the bottom tabbar?
(As an example, look at Spotifys mini-player that's constantly shown above the bottom tabbar)
I have tried to use a ControlTemplate in the ContentPage, but it works so-so.
When navigating between pages, the entire view is "slided away", thus it's noticeable that the control is not static and instead instantiated per each page.
Deactivating animations partially solves it but makes the application feel very static and is thus not an acceptable solution.
Anyone got an idea of how this can be solved?
It's quite easy to solve it with Xamarin.Android and Xamarin.Ios, but this needs to be done in Xamarin Forms.
Thanks in advance.

Difference between Prism Dialogs vs Popup

I am implementing Prism in a new Xamarin Forms App. I have been using Rg.Plugins.Popup in the app before converting to Prism.
What are the limitation on the Prism Dialogs vs Prism.Plugin.Popups?
What are some examples when you would use one over the other?
Thank you!
Rg.Plugins.Popup is a popular plugin for Xamarin.Forms which accesses the native functionality to provide a "Modal Popup" which traditionally has not been achievable with Xamarin.Forms.
Dialogs in Prism 7.2
If you're using Prism 7.2 you'll find that the DialogService locates the currently displayed page and then "reparent's the content". Or in other words it takes the content of the active Content Page and places it as the root child of an AbsoluteLayout, placing a mask layer and finally your dialog on top. As a result of this approach you'll notice that any navigation bars for instance on the NavigationPage or TabbedPage, or a MasterDetailPage's menu will remain accessible to the user.
While in some regard both the PopupPage and Dialog may look very similar as you can probably tell there is some significant divergence there.
Dialogs in Prism 8
If you're using Prism 8.0 you'll see that we have updated to the latest Xamarin.Forms and as a result we are able to take advantage of a new feature in Xamarin.Forms which allows you to present a Modal Page with a Transparent background. This in effect allows you to replicate the effect of a PopupPage with either some benefits or drawbacks depending on how you look at it.
With Rg.Plugins.Popups you have the ability to push a PopupPage on top of whatever page is currently displayed from anywhere in the app
With Xamarin.Forms page's that have been pushed Modally they are part of your active Navigation Stack
Using the a traditional page with a transparent background and Modal Navigation you in effect have replicated the appearance of what you get with a PopupPage
Limitations
Prism.Plugin.Popups has the benefit of being integrated into the Navigation Service. As such you can inject the Navigation Service into the ViewModel of a PopupPage, and the PopupPage will be dismissed when you navigate away from it to another non PopupPage.
Dialogs are not part of the Navigation Stack tracked by Prism's Navigation Service. Navigation in Xamarin.Forms is dependent on navigating FROM a specific page. Since Prism's NavigationService doesn't know about the Dialog you will need to dismiss the dialog before navigating.
Other Key Differences
Besides what I've mentioned so far the only real difference is that Rg.Plugins.Popup gives you some added animations which honestly I've seen very few people using.

Tabview vs. GridLayout vs. DockLayout

I checked almost every demo application from the website, but nobody use tabview, only Gridlayout or docklayout for "tabbing" purposes. What is the benefit of the Gridlayout instead of tabview? Apart from the customize the background.
My point is to have a native tab look and feel on every page.
If I have page 1, page 2, page 3, all the page components should have the same tabview/GridLayout part, or I can move out the tabview section to an individual global component?
Apologize for the basic question.
Thanks!
If you are looking for pure native look and feel, you would go with a TabView. Another advantage with TabView is lazy loading, it loads the page only when required.
You may go with GridLayout when you want to keep the TabView look similar on both iOS and Android. iOS by default uses Tabs at bottom and Androids places them at top. iOS would give you a More tab when the number of tab exceeds the available space, on Android it will be scrollable. These are by native, so if you want a customised common look and feel, then you could use GridLayout. Or still you could use the TabView and replace the TabBar with your own custom view, which is a bit complicated.
If you want the tabs on every page, then you should probably have a Frame inside each tab and load your pages there. So the TabBar remains same on every page. The same could be achieved with GridLayout, it's all about choices. I personally like sticking with the native look and feel of platform.

How to allow Xamarin Forms TabbedPage to control the tabMode in Tabbar.axml for Android

I want to have different TabbedPages within my app with different tabModes.
IE:
TabbedPageOne with app:tabMode="scrollable"
TabbedPageTwo with app:tabMode="fixed"
This is currently possible? If not, how can it be achieved?
The setting can be easily changed app wide (How to make Tabbed page of many content page with a scroll menu in Xamarin forms?), but want it to be configurable per TabbedPage.

Resources