Here comes another code that crashes Fuse Tools.
ux:
<App Theme="Basic" ClearColor="#fff">
<StackPanel>
<TextInput TextChanged="changed" />
</StackPanel>
</App>
Uno:
public partial class MainView
{
void changed(object sender, TextChangedArgs args) {
TextInput origin = (TextInput) sender;
origin.Text = args.OldText; }
}