How to make a TextBlock of an UWP-Application update automatically? - xaml

Question

I have a background-thread which updates a Integer-value once per second. How can I map this Integer to a Text-Field of my XAML form that the Form always shows the current value and updates automatically if the Integer changes?

Answer 1

You can use a ViewModel with a binding.
With OnPropertyChanged() it will automatically changed and displayed in your UI.
here is an example to give you an idea
use in your xaml:
<TextBox x:Name="MyTextBox" Text="{Binding Name}".../>
in your code behind:
...
var vm = new ViewModel("Nr.7");
this.BindingContext = vm;
foreach(var x in Whatever)
{
vm.Name = x;
}
using System.ComponentModel;
using System.Runtime.CompilerServices;
namespace MyAppNamespace
{
// This class implements INotifyPropertyChanged
// to support one-way and two-way bindings
// (such that the UI element updates when the source
// has been changed dynamically)
public class ViewModel : INotifyPropertyChanged
{
private string name;
// Declare the event
public event PropertyChangedEventHandler PropertyChanged;
public ViewModel()
{
}
public ViewModel(string value)
{
this.name = value;
}
public string Name
{
get { return name; }
set
{
name = value;
// Call OnPropertyChanged whenever the property is updated
OnPropertyChanged();
}
}
// Create the OnPropertyChanged method to raise the event
// The calling member's name will be used as the parameter.
protected void OnPropertyChanged([CallerMemberName] string name = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(name));
}
}
}