Sometimes, users inside your app will need access to another app to complete their task. Maybe its calling someone, viewing a webpage or launching Skype. When you call upon another app you need to use its URI Scheme.
Working with the Android Manifest
This scheme is what is registered with the platform, and it links it to an app that can handle the request. For example, when Skype installs on your device, it will register the URI Scheme skype with the platform. If you want to pass information to the app you can do so via the string you send to the platform. If you want to learn how your app can register itself with the platform, to receive requests, have a look at Registering A URI Scheme.
While there are some caveats to iOS, which I will go through shortly, this is generally all that is needed. However, it lacks certain functionality, such as notifying you if any app did take the request.
To extend the functionality, lets create our own, OpenUri, called LaunchApp. First create an interface to call the new method. You will need to use Dependency Injectionto provide this functionality to your Xamarin Forms application.
Now lets create each implemention on each platform. Also note, that these methods, should be called in the UI Thread. Due to increased security requirements in iOS9, if you want to know if an app was launched you need to specify which apps you may launch from your app, in the info. This security requirement was added because some apps were using this functionality to determine what other apps you had installed. In your info.
Some exceptions to this rule are default apps, such as the browser, or making a call. Functions that every device has. Subscribe to a hand-picked round up of the best Xamarin development links every week.
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Signup to Weekly Xamarin. But is there somewhere a list of all available shortcuts?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. The idea is to provide a method for opening files in the application by default. I'm not sure exactly what you mean by this.
We have Launcher. Redth sir, suppose i wanted to open PDF file in my app. Redth as written by gsmental when we need to open some files for example, pdf, docx I would like to add some precision to this request. Doing this, I get an Exception on Android device : Android. Before that, I managed this situation with platforme specific code, like for Android : Android. StartActivity intent.
My understanding of the use case is that you really just want to show the platform's native 'share' dialog to let the user pick how to handle a given file. On android that exception is likely due to the fact you are giving a private file path. This is the work we are doing around using a file provider on android See The idea would be you give the API any file path that you want to share, it will run it through the file provider on android to generate a shareable uri, and then we'd use the native share dialog so on Android it would pretty much be launching an intent - we might need to discuss how things like content type are inferred or set for this.
I'm thinking this issue is really a duplicate of Anybody see a reason this should be kept separate and open? If no objections I'm going to close this one as a duplicate I don't think it is a duplicate of I think we are in the same way than the Media Plugin from James Montemagno.
I don't need to share data with other application. I just want to see the file content with the right default application. Perhaps the nomenclature is the problem here. I think this is still technically 'sharing' data with another application, it's just 'sharing' a file that you want another application to open.
Showing PDF files in Xamarin.Forms
This is what our 'sharing' API is really being designed to do. I'm still not convinced this is a separate issue from We are closing this issue since no response was received. Please open a new issue referring to this one if you have more information. Hi everyone! In my case Android experience when an application have the ability to work with files for example Slack, Whatsapp, etcif I want to open a file for some reason, the app shows me one of the two following options: a Open the file using one of my installed apps intended to do that.
I agree with those that see this is a separate issue from what the Share functionality gives you currently. It is sharing in a sense as Redth points out, but when you Share. RequestAsync the file gets looked at as a file and you get certain options for a file generically speaking. If you instead were to tap on that file in the built-in file browser for your system you would get a different set of options or it would automatically open because you've previously associated that file type with an app.
In that case it looks more at the file extension, e. Basically: This will be just a quick-and-dirty blog on showing PDF files in your Xamarin. Forms application. Showing a PDF file seems a very easy task, and depending on what platform you are targeting; it is. It will show nicely. You will just have to add a teensy bit of magic to enable zooming, but that is it.
For Android and Windows it is a bit different. Ideally, you would want to keep your users in your app when showing a PDF file. Forms way. I will start with the shared Forms code and then implement iOS, since that is the easiest one. This way we could choose to cache it and not having to download it every time. You could choose to just load the external URL and show that. In the shared code I have a very simple page which shows a WebView.
Normally you would probably not have this page as a first, but somewhere in your app when navigating to an invoice for example. The UI can be see underneath. The custom PdfWebView control is literally nothing more than just a inheritance of the regular WebView. This is needed so I can create a custom renderer for it.
The code-behind for this page is a bit more extensive. In the constructor a URL is provided which is then processed through the ILocalFileProvider, which is the dependency service code to save the file to the right place and tell us where that place is. Another thing that you will also notice is that there is a distinction between Android and the rest. Depending on what platforms you will implement you need smarter if-statements or just a better approach altogether, but this will give you the general idea.
Before we move on to the platform code, notice that at the end of the constructor, for Android we set a special URL, while for iOS we just set the WebView source to the local file path. More on that later. As I said; I have implemented some code to download the file first.
So basically, what happens is I provide the downloaded stream already together with a filename, this gets saved and gives me back the local file path and I load that into the WebView. To provide the correct local path, we will need some DependencyService code.
For iOS there is one thing we need to add. This can be done easily by implementing this code on the iOS project:. To overcome this there are several routes to take. I have chosen to incorporate the pdf. There even is a mobile optimized view incorporated. The first thing we need to do is download the pdf.
Showing PDF files in Xamarin.Forms
Make sure the build action for all files is set to AndroidAsset. Have a look at the screenshot below for my project structure. It actually looks very similar to the iOS code, but the difference is that variables which retrieve path names produce different values on each platform. That is the main reason why we need a implementation on each platform we want to do this.This post is about probably my least favorite part of mobile app development — figuring out and assembling all of the various images needed to build an application and publish it into the stores.
Each platform has its own requirements for this, and often you will need to provide multiple resolution versions within each platform in order to handle varying pixel density ratios. To help make my life easier, I like to use a spreadsheet to identify all of the images needed along with the final image resolutions and preferred file names. This works great because I can give this spreadsheet to the UX designer and have them provide all of the assets — already sized and named appropriately so that I can just drop them right into my project.
I will also separate this list into artwork that is needed for the app itself versus artwork needed for the store entries for publication. Generally, images should be in PNG format, and you should provide a version of each image that most closely matches the target device form factor and pixel density. The device will compensate for mismatched images, but the visual quality will not be great and your app will potentially consume far more memory and CPU resources.
To avoid problems with the native platform resource resolution, you should avoid spaces and dashes in filenames. I also suggest using all lowercase names. Newer and more advanced devices tend to support higher densities, because this provides a more crisp and detailed visual experience. In iOS, the pixel density of the original iPhone display is considered to be the baseline.
This yields a density of about DPI dots per inch. Generally speaking, Retina has twice the number of rendered pixels on each side, and Retina HD has triple.
The larger formats are just sharper. In Android, there are more density levels. It should be noted that we rarely need to worry about actual screen pixel size in Xamarin Forms when dealing with general layouts. We work in density-independent units while laying out a UI. At runtime the actual pixels are computed and used the density-independent size is scaled by the pixel density ratioand the appropriate artwork files are loaded.
So for all practical purposes, we pretend that our devices are points wide and either points tall Android or points tall iPhone prior to iPhone 5 or points tall iPhone 5 and 6. We know that we need to supply larger images for higher density formats, and luckily that is an easy thing to do assuming that we are working from a pixel-wide baseline layout. To compute the other sizes needed for this image, you can just rely on the simply multiplication factors for each:.
One special case with iOS artwork is that if you wish to use custom icons for the various built-in button types navigation bar buttons, tab bar buttons, or toolbar buttons then your images should be single-color using an alpha transparency mask. Android projects are structured differently. Instead of using suffixes to designate DPI variations, Android instead uses separate subfolders using a naming convention based on resource qualifier tags.
Android will first search the current device density folder and then fallback to others if it cannot find a resource in the most ideal location.
In iOS you should not round the corners of your App Icons — Apple will do that for you, and it might change from one version of iOS to the next. In Android this icon will also be used in a smaller version at the top left of the navigation bar within your app, unless you have taken steps to hide the icon there.I have now updated my project to xamarin forms 4. Before updating, I was using device. But, after the update this code Device. OpenUri did not work. Probably this code in this version of xamarin forms deprecate.
Hamittirpan - I use:. That's really strange! I never used Xamarin.
Launching A Mobile App Via A URI Scheme
Essentials so far but the only way to upgrade to fix this deprecation is to add yet another library? There is really no other official way of doing that? XavierPerseguers said: Hello.
I agree with that sentiment. Deprecating an API and replacing it by another one is one thing, deprecating an API and saying to pull in another library that I wasn't using previously either is another. Essentials is great, can't imagine writing a Forms app without but agree it should work in Forms or be removed, implemented platform specific code in the passed but essentials takes care of so much now and is well documented.
By continuing to browse this site, you agree to this use.This is a widget used to display date. In this example, we are going to create a date picker which displays the set date on a text view. First of all, create a new project and call it datePickerExample.
Open Main. Next, go to Mainactivity. We first create a private instance of a textview inside the mainActivity:Activity class. In the above code, we have referenced our datepicker, textview, and button by finding them from our main. After referencing, we set the button click event which is responsible for passing the selected date from the date picker to the textview. Next, we create the setCurrentDate method for displaying the default current date to our textview.
The following code explains how it is done. Time Picker is a widget used to display time as well as allowing a user to pick and set time. We are going to create a basic time picker app that displays the time and also allows a user to change the time. Go to main. Go to MainActivity. We then created a click event for the set time button which on click sets the time to the time selected by a person. By default, it shows the current system time. A spinner is a widget used to select one option from a set.
First of all, create a new project and call it Spinner App Tutorial. Open Strings. Next, open MainActivity. In the above code, we referenced the spinner we created in our main. We then created a new arrayAdapter which we used to bind our array items from the strings. Finally we created the method SelectedDay which we used to display the selected day of the week. Xamarin - Android Widgets Advertisements. Previous Page.
Next Page. Previous Page Print Page.In this article, you will learn how to configure app icons in the Xamarin Forms app. Sometimes, things seem more confusing than we think, like setting up the app icons and splash screen in the Xamarin Forms iOS application. This post will mainly cover how to do it in Visual Studio, similar steps can be followed in Xamarin Studio also. The only place to configure the app icons and splash screens for iOS, UWP and not Android is a platform-specific project, as the implementation for each platforms differs.
The file which contains all the information about iOS Application configuration is Info. There are two ways to change the icons and the splash screen of iOS applications. First way:. This is how the icon and the splash screen of my application looked, after I updated them. Android Project Similar to iOS project, the project created by Xamarin Forms template in Visual Studio automatically adds icon images, which look like the following, when we execute the application without any changes.
Follow these steps in order to change the default icon image to your application icon:. You just have to add the imagesas per the given sizes in Visual Assets tab of Package. Also, you can change the name of the Application by changing the Display Name property in Application Tab of the Package.
This is how the icon and the splash screen of my Application looked. The one I used for this post example is MakeAppIcon. Unfortunately, there is no such tool for UWP project, so I have to make the images myself.
If anyone knows any tool, please suggest via comments. The example code of this article can be found at GitHub.
Let me know if I have missed anything or if you have any suggestions. View All. Ravi Kumar Updated date, Jun 14 First way: Copy the icons and splash screen images of same size and resolution, as per the default icons and splash screen images provided by the project template, present in Resources folder. Delete the default icons and splash screen. Rename your icons and splash screen images the same as the default ones. Second way: Create a new asset catalog by right clicking on the asset catalogs and selecting the option Add Asset Catalog from the popup menu.
Add the icon images as per the sizes mentioned in the AppIcons section. Repeat steps 2 and 3 from the above mentioned steps. Follow these steps in order to change the default icon image to your application icon: Copy the icon images of the same size of icon.
Include the images in your project and make sure that the Build Action Property of the image is set to AndroidResource.