Xamarin iOS : Center UILabel inside UICollectionView Header created programmatically - xamarin.ios

Question

The solution for centering any subview within a parent is usually simple, however, it doesn't seem to work in my case.
I'm working with a UICollectionView and have added a Header class programmatically. I have this constructor, where I also try to center the label within the screen:
[Export("initWithFrame:")]
public Header(System.Drawing.RectangleF frame) : base(frame)
{
label = new UILabel
{
Frame = new System.Drawing.RectangleF(frame.Size.Width / 2, 50, 200, 50),
BackgroundColor = UIColor.Clear,
TextColor = UIColor.White,
Font = UIFont.FromName("HelveticaNeueLTStd-ThCn", 35f),
Text = DateTime.Now.ToString("Y")
};
AddSubview(label);
}
And I initialize the class inside the UICollectionViewSource 's constructor like this:
public MyCollectionViewDataSource(MainController mainController, DateTime currentDate)
{
try
{
controller = mainController;
new Header(new RectangleF(0, 0, (float)mainController.View.Frame.Size.Width, 200));
}
catch (Exception ex)
{
Console.WriteLine(ex.Message + ex.StackTrace);
}
}
What exactly am I missing because this usually works in other instances but seems to fail here?
This is what it looks like :

Answer 1

I found an explanation here iOS Layout Gotchas by Adam Kemp which helped me resolve this issue.
The first solution
One very common mistake I made was adding the layout definition code in the constructor, instead of doing it in the rightful place : the LayoutSubviews override in this case.
Giving the label the frame size in the constructor assumes a static size set at the time of construction, which may later change depending on the screen size.
The second solution
He explains that :
Frame sets the position of a view within its parent while Bounds is in the coordinate system of the view itself (not its parent).
So, to center the UILabel, I used bounds and center together and this worked for me.
[Export("initWithFrame:")]
public Header(CGRect bounds) : base(bounds)
{
label = new UILabel
{
BackgroundColor = UIColor.Clear,
TextColor = UIColor.White,
Font = UIFont.FromName("HelveticaNeueLTStd-ThCn", 35f),
Text = DateTime.Now.ToString("Y"),
TextAlignment = UITextAlignment.Center
};
rectangle = bounds;
AddSubview(label);
}
public override void LayoutSubviews()
{
base.LayoutSubviews();
label.Bounds = new CGRect (rectangle.Size.Width / 2, 50, 200, 50);
label.Center = new PointF((float)rectangle.Size.Width/2,50);
}