public void DataContext_Binding_Should_Produce_Correct_Results()
{
var root = new Decorator
{
DataContext = new { Foo = "bar" },
};
var child = new Control();
var dataContextBinding = new Binding("Foo");
var values = new List<object>();
child.GetObservable(Border.DataContextProperty).Subscribe(x => values.Add(x));
child.Bind(ContentControl.DataContextProperty, dataContextBinding);
root.Child = child;
Assert.Equal(new[] { null, "bar" }, values);
}
public void DataContext_Binding_Should_Track_Parent()
{
var parent = new Decorator
{
DataContext = new { Foo = "foo" },
};
var child = new Control();
var binding = new Binding
{
Path = "Foo",
};
child.Bind(Control.DataContextProperty, binding);
Assert.Null(child.DataContext);
parent.Child = child;
Assert.Equal("foo", child.DataContext);
}
public void DataContext_Binding_Should_Produce_Correct_Results()
{
var viewModel = new { Foo = "bar" };
var root = new Decorator
{
DataContext = viewModel,
};
var child = new Control();
var values = new List<object>();
child.GetObservable(Control.DataContextProperty).Subscribe(x => values.Add(x));
child.Bind(Control.DataContextProperty, new Binding("Foo"));
// When binding to DataContext and the target isn't found, the binding should produce
// null rather than UnsetValue in order to not propagate incorrect DataContexts from
// parent controls while things are being set up. This logic is implemented in
// `Avalonia.Markup.Xaml.Binding.Initiate`.
Assert.True(child.IsSet(Control.DataContextProperty));
root.Child = child;
Assert.Equal(new[] { null, "bar" }, values);
}
