Grid not resizing when child's visibility is changed - xamarin

Question

I have a Xamarin app with a Grid, where there is a Label and an Entry.
When I change the Entry’s text, I want the Label to be visible, and if it is empty, it shall not show the Label.
I have created a demo-app to verify, that it does not have anything to do with my code. But the following code also fails
MainPage = new ContentPage
{
Content = new Grid
{
ColumnDefinitions = new ColumnDefinitionCollection
{
new ColumnDefinition { Width = new GridLength(1,GridUnitType.Auto) },
new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) }
}
}
};
Label label;
Entry entry;
Grid mainGrid = ((Grid)((ContentPage)MainPage).Content);
mainGrid.Add(btnDelete = new MR.Gestures.StackLayout
{
Children = {
new ExtendedLabel { Style = Styles.LargeLabelIcon, Text = "\ue634", TextColor = Color.Black }
},
WidthRequest = 50
}, 0, 0);
mainGrid.Children.Add(label = new Label { Text = "TEST", IsVisible = false }, 0, 0);
mainGrid.Children.Add(entry = new Entry { }, 1, 0);
entry.TextChanged += (sender, arg) => label.IsVisible = entry.Text.Length > 0;
Does anybody have an idea of how to fix it?

Answer 1

I am not sure if this is what your are trying to achieve:
MainPage = new ContentPage
{
Content = new Grid
{
ColumnDefinitions = new ColumnDefinitionCollection
{
new ColumnDefinition { Width = new GridLength(1,GridUnitType.Auto) },
new ColumnDefinition { Width = new GridLength(1, GridUnitType.Star) }
}
}
};
Label label;
Entry entry;
Grid mainGrid = ((Grid)((ContentPage)MainPage).Content);
mainGrid.Children.Add(label = new Label {
Text = "TEST",
IsVisible = false,
VerticalOptions = LayoutOptions.Center,
HorizontalOptions = LayoutOptions.Start,
}, 0, 0);
mainGrid.Children.Add(entry = new Entry {
HorizontalOptions = LayoutOptions.FillAndExpand,
VerticalOptions = LayoutOptions.FillAndExpand,
BackgroundColor = Color.Black,
TextColor = Color.White
}, 1, 0);
entry.TextChanged += (sender, arg) => label.IsVisible = entry.Text.Length > 0;
I have added vertical and horizontal options to the controllers.

Answer 2

I just had a very similar issue. After the text on my child component was changed, it would be cut-off.
The problem turned out to be that you can't mix a ColumnDefinition of * on the grid with a HorizontalOptions on the child. Having both seems to break something. Replacing it with HorizontalTextAlignment fixed it for me.
Maybe this will help someone else someday.