Xamarin.Forms

Creating custom controls

Creating custom Button

/// <summary>
/// Button with some additional options
/// </summary>
public class TurboButton : Button
{
    public static readonly BindableProperty StringDataProperty = BindableProperty.Create(
      propertyName: "StringData",
      returnType: typeof(string),
      declaringType: typeof(ButtonWithStorage),
      defaultValue: default(string));

    public static readonly BindableProperty IntDataProperty = BindableProperty.Create(
      propertyName: "IntData",
      returnType: typeof(int),
      declaringType: typeof(ButtonWithStorage),
      defaultValue: default(int));

    /// <summary>
    /// You can put here some string data
    /// </summary>
    public string StringData
    {
        get { return (string)GetValue(StringDataProperty); }
        set { SetValue(StringDataProperty, value); }
    }

    /// <summary>
    /// You can put here some int data
    /// </summary>
    public int IntData
    {
        get { return (int)GetValue(IntDataProperty); }
        set { SetValue(IntDataProperty, value); }
    }

    public TurboButton()
    {
        PropertyChanged += CheckIfPropertyLoaded;
    }

    /// <summary>
    /// Called when one of properties is changed
    /// </summary>
    private void CheckIfPropertyLoaded(object sender, PropertyChangedEventArgs e)
    {
        //example of using PropertyChanged
        if(e.PropertyName == "IntData")
        {
            //IntData is now changed, you can operate on updated value
        }
    }
}

Usage in XAML:

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage
    xmlns="https://xamarin.com/schemas/2014/forms"
    xmlns:x="https://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="SomeApp.Pages.SomeFolder.Example"
    xmlns:customControls="clr-namespace:SomeApp.CustomControls;assembly=SomeApp">
    <StackLayout>
        <customControls:TurboButton x:Name="exampleControl" IntData="2" StringData="Test" />
    </StackLayout>
</ContentPage>

Now, you can use your properties in c#:

exampleControl.IntData

Note that you need to specify by yourself where your TurboButton class is placed in your project. I’ve done it in this line:

xmlns:customControls="clr-namespace:SomeApp.CustomControls;assembly=SomeApp"

You can freely change “customControls” to some other name. It’s up to you how you will call it.


This modified text is an extract of the original Stack Overflow Documentation created by the contributors and released under CC BY-SA 3.0 This website is not affiliated with Stack Overflow