The visual appearance will be almost identical, but the implementation will be conceptually different.
Forms’ layout classes and options offer a powerful toolset for arranging visual elements on the mobile screen.
In rare cases, however, you might want to compute positions or dimensions based on the current screen size.
Thus, the layout description spreads across two files and two languages, which increases the complexity of our project structure. Forms be implemented using C# only, we restrict ourselves to C# within this book.
And since most of the XAML is only parsed at run-time, the code-completion, syntax-highlighting and source code analysis is incomplete and sometimes misleading. But we don’t want to withheld at least one XAML example.
The number of rows or columns would then be automatically derived from the children added afterwards.
Those child elements are identical to the ones added to the is probably the most powerful layout.
In this chapter we will have a detailed look into each of these three projects. This is all it takes to define the UI of our first cross-platform app.
This not only lets you play with the examples contained in the book, but gives you early access to new demos for future book editions. The new solution contains basically three projects: a shared project with all the cross-platform business logic and UI description as well as two projects with the platform specific integration and customization for Android and i OS devices. And the layout options just take care that it is nicely centered on the page.
This can involve a custom visualization or even custom gesture-based user interaction. The latter is a technique to avoid “staircases” when drawing sloped lines and shapes, which generally yields more visually pleasing results at the cost of slightly more computing time.
The Custom renderers are not only useful for displaying UI elements in a different way than usual, but they can also connect the shared code with platform-specific gesture detection.
With a copy of the book you get free access to the Git Hub repository containing the workspace with all compiling solutions and source code. In Xamarin Studio we create a new solution of type “Xamarin. For shared code we choose the “Use Shared Library” option.