Xamarin access to entry in other view - xamarin

Question

I'm developing Multiplatform app through Xamarin.
I'm using custom entry in a separate view and I'm using in some pages of my app
This is my simple code for entry
<ContentView
xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="prova.MyView">
<ContentView.Content>
<Entry x:Name="MyEntry"
TextChanged="MyEntry_TextChanged"
Margin="100"/>
</ContentView.Content>
and cs file
public partial class MyView : ContentView
{
public MyView()
{
InitializeComponent();
}
void MyEntry_TextChanged(System.Object sender, Xamarin.Forms.TextChangedEventArgs e)
{
}
}
in my pages I insert entry with this simple code
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="prova.MainPage"
xmlns:pages="clr-namespace:prova">
<StackLayout>
<pages:MyView/>
</StackLayout>
I wonder how can I get when MyEntry_TextChanged is fired in my ContentPage?
one solution is to use MessaggingCenter but I wonder if there's a better and more elegant solution

Answer 1

There are two ways I can think of to do this.
1. Inherit from the Entry class as Jason commented.
public class MyView : Entry
{
public MyView()
{
InitializeComponent();
}
}
This will expose the bindable TextChanged property which you can reference in XAML like you want to do.
2. Create the binding yourself
You can create the binding to a custom "TextChanged" property yourself, but this is more complicated and may achieve the same result with extra effort. You will also need to create a bindable "Text" property. The code below is untested, but uses the bindings I found in the Xamarin.Forms InputView class (which is what Entry derives from). This will be along the lines of what you need to do if you do not do it the way of #1. Exposing bindable properties to XAML will look like this:
public class MyView : ContentView
{
public MyView()
{
InitializeComponent();
}
public string Text
{
get
{
return (string)GetValue(TextProperty);
}
set
{
SetValue(TextProperty, value);
}
}
public static readonly BindableProperty TextProperty = BindableProperty.Create("Text", typeof(string), typeof(MyView), defaultValue: "", propertyChanged:
(bindable, oldValue, newValue) => ((MyView)bindable).OnTextChanged((string)oldValue, (string)newValue));
public event EventHandler<TextChangedEventArgs> TextChanged;
protected virtual void OnTextChanged(string oldValue, string newValue)
{
TextChanged?.Invoke(this, new TextChangedEventArgs(oldValue, newValue));
}
}
I hope my more comprehensive answer helps you choose the direction you want to go for this. If you want to learn more about Bindable Properties, check out Edward's link.