Swift-添加两个UI数字然后在标签中输出

Question

我可以在 C++/C、Objective C 和 Playground 中做到这一点。当我尝试制作应用程序时，我无法在 Swift 中使用它。

有人可以帮忙吗？

//
//  ViewController.swift
//  Simple Mathemtical Functions_Swift
//
//  Created by  on 7/01/2015.
//  Copyright (c) 2015 . All rights reserved.
//
import UIKit

class ViewController: UIViewController {

    @IBOutlet var labelResult: UILabel!
    @IBOutlet var Number2: UILabel!
    @IBOutlet var Number1: UILabel!
    @IBOutlet var field1: [UITextField]!
    @IBOutlet var field2: [UITextField]!
    @IBAction func Calculate(sender: AnyObject) {
    labelResult.text = "\()"}

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.\

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

}

Answer 1

可能您遇到了问题，因为 field1.text 是 String? 而不是 NSString。

@IBAction func Calculate(sender: AnyObject) {
    labelResult.text = "\((field1.text as NSString).floatValue + (field2.text as NSString).floatValue)"
}

Answer 2

如果 field1 和 field2 并且只有 UITextField，则 [UITextField]! 应更改为 UITextField!。 [UITextField]表示UITextField个数组。

@IBOutlet var labelResult: UILabel!
@IBOutlet var Number2: UILabel!
@IBOutlet var Number1: UILabel!
@IBOutlet var field1: UITextField!
@IBOutlet var field2: UITextField!


@IBAction func Calculate(sender: AnyObject) {

    var a = (field1.text as NSString).floatValue
    var b = (field2.text as NSString).floatValue
    var sum = a + b
    labelResult.text = "\(sum)"

}

Swift-添加两个UI数字然后在标签中输出

Swift- Adding Two UI Numbers then Output in Label

swift