Xamarin.Forms - possible to set an element property globally?

Question

Say I want an Entry element to not have auto-correct or auto-capitalize. This can be done by setting its Keyboard property like so:

new Entry { Keyboard = Keyboard.Create(0) }

Now, how do I make that the global default for all Entry elements?

I know I can create a custom element that inherits from the built-in element, and override the property that way, like:

public class EntryCustom : Entry
{
    public EntryCustom()
    {
        Keyboard = Keyboard.Create(0);
    }
}

and then simply call it like:

new EntryCustom { ... }

But is there a way to do this directly on the built-in element type, without creating a custom element type?

Answer 1

You can do this by saving the custom keyboard into a static and then binding it to all Entry fields using a default style. You can place that default style into an application-wide resource dictionary, which is automatically applied throughout the application. Here is sample code that I just tested to verify in a new empty Forms project:

Step 1. Save the custom keyboard into a static.

Keyboards.cs (static custom keyboard):

using Xamarin.Forms;

namespace KeyboardDemo
{
    public static class Keyboards
    {
        public static Keyboard Unassisted { get; private set; }

        static Keyboards ()
        {
            Unassisted = Keyboard.Create (0);
        }
    }
}

Step 2. Create an App.xaml for your project.

Follow this tip to add an App.xaml to your Forms project: http://jfarrell.net/2015/02/02/centralize-your-styles-with-xamarin-forms/

Step 3. Add the default style to App.xaml

App.xaml:

<?xml version="1.0" encoding="UTF-8"?>
<Application 
        xmlns="http://xamarin.com/schemas/2014/forms" 
        xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
        xmlns:demo="clr-namespace:KeyboardDemo" 
        x:Class="KeyboardDemo.App">

    <Application.Resources>
        <ResourceDictionary>
            <Style x:Key="EntryStyle" TargetType="Entry">
                <Setter Property="Keyboard" Value="{x:Static demo:Keyboards.Unassisted}" />
            </Style>
            <Style BasedOn="{StaticResource EntryStyle}" TargetType="Entry" />
        </ResourceDictionary>
    </Application.Resources>

</Application>

Step 4. Add a new page to the project

Add a ContentPage to the application, with plain Entry controls to verify the styling.

App.xaml.cs:

using Xamarin.Forms;

namespace KeyboardDemo
{
    public partial class App : Application
    {
        public App ()
        {
            InitializeComponent ();
            MainPage = new MyPage ();
        }
    }
}

MyPage.xaml:

<?xml version="1.0" encoding="UTF-8"?>
<ContentPage 
        xmlns="http://xamarin.com/schemas/2014/forms" 
        xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" 
        x:Class="KeyboardDemo.MyPage">
    <ContentPage.Padding>
        <OnPlatform x:TypeArguments="Thickness" iOS="0,20,0,0" Android="0" WinPhone="0" />
    </ContentPage.Padding>

    <StackLayout>
        <Entry />
    </StackLayout>
</ContentPage>