[Swift 開發] 使用閉包傳值(typealias)

在Swift中使用閉包來實現兩個界面的傳值

 

例如:有A類和B類.

B類

//聲明閉包
typealias valueBlock = (Float)->()
var returnPrice: valueBlock?
 
 
//調用該閉包
self.returnPrice?(price)

A類

let sb = UIStoryboard(name:"Main", bundle: nil)
        
let vc = sb.instantiateViewControllerWithIdentifier("keypadViewVC") as! keypadViewVC
        
//B類的回調
vc.returnPrice = {price in self.gratuityBtn.setTitle(String(format: "%.2f", price), forState:UIControlState.Normal)}
        
self.presentViewController(vc, animated: true, completion: nil)