Progress Indicator not showing

Hi

I have a progress indicator in my C# code that is not showing... Am not making use of XAML but build UI in C# code.

_progressIndicator = new ActivityIndicator
{
HorizontalOptions = LayoutOptions.Center,
Color = Color.Black,
BackgroundColor = Color.Black,
IsVisible = true,
IsRunning = true
};

_stackContentLayout.Children.Add (_progressIndicator);

protected void ShowProgressIndicator() {
if (_progressIndicator != null) {
_progressIndicator.IsVisible = true;
_progressIndicator.IsRunning = true;
}
}
protected void HideProgressIndicator() {
if (_progressIndicator != null) {
_progressIndicator.IsVisible = false;
_progressIndicator.IsRunning = false;
}
}