要将数据从一个嵌入式ViewController传递到另一个嵌入式ViewController
,请让父级处理传输。在这里,我提供了一个完整的示例,其中包含三个ViewController和一个StringTaker协议。主要ViewController和LabelViewController
实现此协议。mainViewController
从中获取一个字符串ButtonViewController
,并将其传递给嵌入式LabelViewController
。
import UIKit
protocol StringTaker: class {
func takeString(string: String)
}
class ViewController: UIViewController, StringTaker {
weak var stringTaker: StringTaker?
override func viewDidLoad() {
super.viewDidLoad()
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if segue.identifier == "EmbedButtonViewController" {
let dvc = segue.destinationViewController as! ButtonViewController
dvc.delegate = self
} else if segue.identifier == "EmbedLabelViewController" {
let dvc = segue.destinationViewController as! LabelViewController
stringTaker = dvc
}
}
// Receive the string from the ButtonViewController
func takeString(string: String) {
// Pass it to the LabelViewController
stringTaker?.takeString(string)
}
}
import UIKit
class ButtonViewController: UIViewController {
weak var delegate: StringTaker?
override func viewDidLoad() {
super.viewDidLoad()
}
@IBAction func generateString(sender: UIButton) {
let cities = ["Boston", "Paris", "Sydney", "Mumbai", "Lima"]
// Pick a random city
let city = cities[Int(arc4random_uniform(UInt32(cities.count)))]
// Pass the string to the delegate
delegate?.takeString(city)
}
}
import UIKit
class LabelViewController: UIViewController, StringTaker {
@IBOutlet weak var myLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
}
func takeString(string: String) {
myLabel.text = string
}
}
注意事项: