Float 到 Int 轉換時崩潰

Question

我的實時應用程序在 Float 到 Int 轉換線上隨機崩潰。

我無法弄清楚為什么它會崩潰並且無法重現它，因為它是實時應用程序上的隨機崩潰。 關於如何修復崩潰的任何建議？

崩潰日志

Crashed: com.apple.main-thread
0  MyApp                0x100703778 closure #1 in MyViewController.getBalance(isRefreshed:) + 797 (MyViewController.swift:797)
1  MyApp                0x1005c7670 closure #1 in closure #1 in fetchtBalance(completed:) + 185 (Utils.swift:185)
2  MyApp                0x10051ab10 thunk for @escaping @callee_guaranteed () -> () + 4335790864 (<compiler-generated>:4335790864)
3  libdispatch.dylib              0x1ae908b7c _dispatch_call_block_and_release + 32
4  libdispatch.dylib              0x1ae909fd8 _dispatch_client_callout + 20
5  libdispatch.dylib              0x1ae915cc8 _dispatch_main_queue_callback_4CF + 968
6  CoreFoundation                 0x1aebdee0c __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 16
7  CoreFoundation                 0x1aebd9b68 __CFRunLoopRun + 1980
8  CoreFoundation                 0x1aebd9084 CFRunLoopRunSpecific + 480
9  GraphicsServices               0x1b8e27534 GSEventRunModal + 108
10 UIKitCore                      0x1b2d49670 UIApplicationMain + 1940
11 MyApp                0x1004ec6b8 main + 20 (ClientMyProfileViewController.swift:20)
12 libdyld.dylib                  0x1aea58e18 start + 4

代碼

import UIKit

var balance: String!
var cost: String?

func getBalance () {
    fetchBalance() { (result, error) in
        guard let balanceFloatValue = Float(balance!) else {
            print("Error")
            return
        }

        guard let costFloat = Float(cost!) else {
            print("Error")
            return
        }

        let costPerSec = costFloat / 60

        let talkTime = balanceFloatValue / costPerSec

        let talkTimeInt = Int(talkTime) // Line No. 797  Crash here

        // ....
    }
}

Answer 1

此錯誤的最可能原因是值本身

let a:Float = 9999999999999999999999.9
let b = "0.000000000000000000001"
let c:Float = a/Float(b)!
let x = Int(c)  // <- Crash here

0/0 會讓你崩潰： let c:Float = a/Float(b)! 所以這不是它，但任何其他可以使通話時間在 Int 之外的東西都會讓你崩潰這也可以解釋為什么你只會隨機遇到錯誤，因為它只適用於使除法 NaN 或 inf 或 int 之外的東西的值，如 bg2b說過

Answer 2

我認為您正在強制展開余額值。 嘗試解開轉換后的值，如：„Float(balance)!“

Answer 3

您可以像這樣快速將浮點值轉換為整數值：

var myIntValue = Int(myFloatValue)