any idea how I can start a native UWP page from a Xamarin Forms page?
The reason why I'm asking:
I have a XF application that needs to start a UWP library after a click event.
This library provides a special ORC reader.
Therefore I created a dependency service to run the platform specific function.
What I need now, is to open that UWP page, that contains the "Camera stream" to show the user what he is currently scanning.
And this is where I am hanging at the moment.
In my class that is called from the dep. service, I
myPage mp = new myPage();
But how can I show the new page?
Frame fr = Window.Current.Content as Frame gives me the error, that this page cannot be converted from a XF Frame to a Window Frame.
Or is there generally another way to handle this? Some advice would be great.
This sounds like a custom renderer.
Create a new OcrView class in your shared project inherited from View.
Place it on your Xamarin Forms XAML page.
Handle the OCR component in the UWP renderer.
Have a look at the Implementing a View section on this custom renderer overview
Related
I'm creating a mobile application using Xamarin forms, As part of my implementation, I have a requirement to to show file chooser on clicking on camera icon which is loaded in webView. I have seen several samples for the same, but all those samples and examples in stack is written in native code for Android . Is that possible to do it using Xamarin forms alone? It would be good, if a get a proper sample also for the same.
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.
I am using xamarin.forms mvvm light architecture and targeting Android & iOS.
I am currently writing custom renderer for navigation drawer(MasterDetailPage).
I am currently writing custom renderer for Android and i have tried many things.
Currently my MasterDetail Page renders according to OS's default behaviour i.e. in Android master page starts below the app bar but i wanted my master page to popover app bar or start above the app bar like gmail,stack exchange android app etc
use this theme Theme.AppCompat.Light.NoActionBar for the expected behaviour
There exists one already, as of this writing it is out of date though (not targeting Xamarin Forms 2): https://github.com/nativecode-dev/oss-xamarin. Perhaps you can use that?
I'm trying to add a Xamarin.Forms page to an existing Xamarin Android app.
I'm struggling to figure out how to mix native Xamarin Android pages and Xamarin.Forms pages.
All the articles and examples I have seen describe either Forms or Xamarin apps and not a hybrid of the two.
The best idea I have read about so far is to add a native stub and replace the content with Xamarin.Forms content but I'm not sure how to achieve this.
Update
I'm using MvvmCross so my android view is inherited from MvxActivity. I have a StackLayout containing views using Xamarin.Forms. How do I get XF to convert to android code so I can use with SetContentView?
When you create a new Xamarin.Forms project, for instance with a SharedProject approach, it will create the launcher project and initial class file that will be executed for you for each platform.
For instance on Android this is in MainActivity.cs. If you look inside this file you will notice that it inherits from AndroidActivity which in turn inherits from Activity, which is the typical class used on activities.
So you have two options available for you to create a mixed hybrid solution:-
1) Inherit from AndroidActivity in your platform-specifc stub-page should you want to display Xamarin.Forms content, or alternatively
2) Inherit from Activity, and do the same as usual.
If you want to display a Xamarin.Forms page from the stub-page you can then just use some boiler-plate code such as the following in the OnCreate method:-
SetPage({some class that returns a Xamarin.Forms.Page object, i.e. ContentPage});
You can then use the normal navigation that is specific to Android to either display a Xamarin.Forms page or a platform-specific Activity page.
I’m working on an application for Android and iOS, which requires a certain flexibility for one or two views. That’s why we created & implemented a service that translated a basic list of objects into a user interface for both iOS & Android. But now that Xamarin.Forms is released, we decided to replace our service by the one Xamarin provides. I did succeed in creating the views with Xamarin.Forms, resulting in better looking & smoother running pages. But my problem lies in the navigation of it. Here is a little drawing on what I would like to achieve:
I would like my app to start an activity that starts with a custom fragment. After clicking a button on this fragment, I would like the page I created with the Xamarin.Forms api to be added to my current navigation stack! Once the user is finished with the Xamarin.Forms page, it navigates to a second custom fragment, all that without breaking the navigation cycle. Does anybody have an idea on how I can achieve this?
For the iOS developpers: replace Activity with NavigationController & Fragment with ViewController
Take a look at CarouselPage for Xamarin.Forms' own approach. It doesn't look like that's what you need but you can also look at its source code and maybe make a custom renderer yourself.
You may also want to take a look at MVVM
As for the easier/hackier way you'd want to make a button on each page and when the button is tapped execute Navigation.PushModalAsync(nextPage) - there won't be a "< Back" button any more, you may need to implement that yourself if you need it.
If by your meaning of 'current navigation stack' is for using the native Navigation of each platform, then remember that you don't have to use Xamarin.Forms' Navigation Model and functions such like PushAsync.
If you prefer to do Navigation with code specific to each platform then you can do this the same as normal. Just create your stub pages in each platform specific project and set the Xamarin.Forms content for each page from the shared project.
From each platform specific stub page (Activity / UIView / PhoneApplicationPage) you could then execute an Action<> call setting on the shared Xamarin.Forms page to help with the navigation, or alternatively, hook into a custom-event that is raised from the Xamarin.Forms** page back to the platform specific stub page to allow you to do navigation from there.
Like Sten mentioned there won't be any 'Back' button so you will most likely have to do that yourself.