After adding my image located in the resources I notice that my image appears only at the left bottom of the screen and in a reduced size.
How to fill the image as background on my CLLayer?
I tried adding the image as child and changed the Size of it's content but no success
CCSprite sprite = new CCSprite("img.png");
AddChild(sprite);

You can set
AnchorPointtoAnchorMiddle,then image can be in center of CCLayer:If want image fill the CCLayer,it seems like that there is no way to change size of sprite.So maybe need to change size of image to be more large.
https://learn.microsoft.com/en-us/xamarin/graphics-games/cocossharp/entities#creating-the-ship-entity