我有一个Xcode项目有一些错误。我只对变量有问题。我将txt字符串变量转换为int,这称为txtint。当我想进行计算时,我不能因为它具有空值而不可能,因为我在函数中给出了一个值"传递"然后当我想减去时我不能,因为txtint的值为空。
//
// ViewController.swift
// Biophere
//
// Created by Coder on 2017. 10. 22..
// Copyright © 2017. Pliz Help. All rights reserved.
//
import UIKit
class ViewController: UIViewController {
@IBOutlet weak var label: UILabel!
@IBOutlet weak var textview: UITextField!
@IBOutlet weak var conv: UILabel!
var text: String? = nil
var txt: String? = nil
var convert: String? = nil
var textint: Int? = nil
var txtint: Int? = nil
@IBAction func pass(_ sender: Any) {
var txt: String {
get {
return textview.text ?? ""
}
set {
textview.text = newValue
}
}
//conv.text = txt
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
label.text = text
txt = textview.text
}
@IBAction func saveButton(_ sender: Any) {
let textint = Int(text!)
let txtint = Int(txt!)
convert = String(textint! - txtint!)
conv.text = txt
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
错误:主题1:EXC_BAD_INSTRUCTION(代码= EXC_I386_INVOP,子代码= 0x0)
答案 0 :(得分:0)
var text: String = ""
var txt: String = ""
var convert: String = ""
var textint: Int = 0
var txtint: Int = 0
@IBAction func saveButton(_ sender: Any) {
if let textint = Int(text), let txtint = Int(txt) {
convert = String(textint - txtint)
conv.text = txt
}else{
print("handle it")
}
}
建议:尝试提供变量名称描述,这是开发的基本内容。