Array element cannot be bridged to Objective-C

Question

I have this code that creates a view and applies a gradient to it.

import UIKit
import QuartzCore


let rect : CGRect = CGRectMake(0,0,320,100)

var vista :          


        

Answer 1

The reason Objective-C is mentioned is because UIKit and QuartzCore are Objective-C frameworks. In particular, gradient.colors = arrayColors is calling an Objective-C method that expects an NSArray.

This seems like a bug, as Apple's documentation makes it sound like that the array should auto-bridge to an NSArray so long as the items in the array can be considered AnyObject:

When you bridge from a Swift array to an NSArray object, the elements in the Swift array must be AnyObject compatible. For example, a Swift array of type Int[] contains Int structure elements. The Int type is not an instance of a class, but because the Int type bridges to the NSNumber class, the Int type is AnyObject compatible. Therefore, you can bridge a Swift array of type Int[] to an NSArray object. If an element in a Swift array is not AnyObject compatible, a runtime error occurs when you bridge to an NSArray object.

You can also create an NSArray object directly from a Swift array literal, following the same bridging rules outlined above. When you explicitly type a constant or variable as an NSArray object and assign it an array literal, Swift creates an NSArray object instead of a Swift array.

For now, a work around would be either to declare arrayColors as an NSArray:

let arrayColors: NSArray = [cor1.CGColor, cor2.CGColor]

Or to declare it as taking AnyObject:

let arrayColors: Array = [cor1.CGColor, cor2.CGColor]