In this post I return to the EvalUate application I was building earlier in this series. 

We’re going to add the ability to take a photo of the item you are thinking about buying.  It turns out there are a number of different ways to access the camera, but I was looking for one that would work and play well with Xamarin Forms. 

I’m pleased to say that the Xamarin Forms Labs, (XFL) an open source project, has a Camera service (though it is in Beta). 

XFL looks very exciting and much has been written about it already, though it is comparatively new, with Google returning over 18,000 hits on an exact match.  A number of us at Falafel Software will be blogging about various features from XFL in coming weeks.

Using the Camera with the Xamarin Forms Library

XFL is, as I say, quite young, and so the documentation is not 100% — but there is a wiki and there are samples.  I decided to dive in and modify EvalUate to add the ability to take a picture when you add a new “item.”  Continued here…

Xamarin Forms are the most exciting library to come along in a long time; certainly for mobile programmers. 

They bring a whole new option to cross platform development: an abstraction layer that lets you write once, and run native on each of the platforms. 

Write Once, Render Natively

This means, for example, when you create a tab page, it is rendered as a native tab page on iOS, Android and Windows Phone.  This is accomplished using pre-defined elements each of which has a hidden renderer for each platform.  Most of the time you don’t know or care how it is done, unless you want to create a custom (or customized) control.

Continued here

In yesterday’s post we looked at using HTTP with Web Forms and creating a list of blog posts from an RSS feed. Today we’ll add the ability to tap on one entry in the list and see that blog post in a viewer on the phone.

[Click on image to see full size]

The image shown here, incidentally, is an exact reflection of what is running on my iPhone thanks to a very handy utility named Reflector.  You run reflector and then use AirPlay on the phone to mirror what is on your phone onto the screen.

This is part of the on-going series of posts on Learning Xamarin; a complete index to the series can be found here.

This addition to our program is shockingly easy. Continued here.

Let’s say we’re building an application, and we want to list the titles and publication dates from an RSS feed. 

We can do this using a ListView, but we have to get the feed, and to do that we need a library; specifically the NuGet package Microsoft.Http.Client Libraries. 

[Click on image for full size]

This is part of the on-going series of posts on Learning Xamarin; a complete index to the series can be found here.

To create our application we’ll start with a new Forms application by firing up Xamarin Studio and selecting New Solution ->  C# -> Mobile Apps -> Blank App (Xamarin.Forms.Portable

Continued here

Until now, our application has used simple “push” navigation, creating a stack that the user can pop out of to return to the calling screen. 

It would be convenient, however, to add tabs to the opening screen where the user can access the help file and the license information.

In the figure to the right, you can see that there are three tabs, and the currently selected tab is “help.”

To accomplish this, we’ll add three new pages:

• MainPage will hold the tabs
• HelpPage will hold the help text
• LicensePage will hold the license information

Continued here

The application that I began describing here (and which is part of this series) is almost done. 
Today, we’ll add a new first page to allow the user to track more than one appliance type.  This will require minor changes throughout the application and a change to the database. 
The key concern would be that we already have data in the database and now I not only want to add a table, but I want to add a property to one of the existing (and populated!) tables. 
Turns out that SQLite.net makes this a total non-issue, handling the update perfectly with no effort on my part.

Continued here