ios - Swift: could not find an overload for conversion that accepts supplied argument -

ios - Swift: could not find an overload for conversion that accepts supplied argument -

if set argument nil, error appears. code this:

func addchild(childtoadd: uiviewcontroller, childtoremove: uiviewcontroller) { if (childtoremove != nil) { childtoremove.view.removefromsuperview() } var frame = childtoadd.view.frame cgrect frame.size.width = view.frame.size.width; frame.size.height = view.frame.size.height; childtoadd.view.frame = frame view.addsubview(childtoadd.view) } override func viewdidload() { super.viewdidload() addchild(firstviewcontroller, childtoremove: nil) //could not find overload conversion accepts supplied argument }

as can see, should not set nil in there, should set into. it's working in objective-c.

your childtoremove parameter defined uiviewcontroller, not optional so cannot nil

try :

func addchild(childtoadd: uiviewcontroller, childtoremove: uiviewcontroller?) {

to allow nil value sec parameter, , don't forget need disclose optional before using (using if let great way so) :

if allow childcontroller = childtoremove { childcontroller.view.removefromsuperview() }

ios swift