如何查找在ViewDidLoad中调用的UIImage的值，并传递到Swift中的另一个函数

Question

I am using a simple function to call a random image when a view controller is loaded.

override func viewDidLoad() {
    super.viewDidLoad()
    var randomtest = ReturnRandom()
    mainImage.image = UIImage(named: randomtest)
}

I want a button's action to be based on what image was displayed. For example

@IBAction func Button1(sender: AnyObject) { 
switch randomtest {
case 1: //Do something here
case 2: //Do something different here
default:  
}

However I can not figure out how to get the value of "randomtest" out of ViewDidLoad. I also can not seem to create the random number outside the ViewDidLoad then pass the variable in. Sorry I'm new to all this, iOS development is a long way away from php...

Answer 1

The reason I was having trouble declaring the result of my function as a instance variable is that my function is also an instance function . I can not call it, there has been no instance. So this

class ViewController : UIViewController {

var randomtest: Int = ReturnRandom();

Will return a "Missing argument for parameter #1 in call" For more details please check out this very helpful thread on setting initial values . Since my function was so simple I just computed the property while setting the initial value, no need for an additional class level function.

dynamic var randomtest:String {
let imageNumber = arc4random_uniform(3)
var imageString = String(imageNumber)
return (imageString)}

Hope this helps someone.