Question

我下面的快速代码可能需要几秒钟的时间并从文本字段中倒数，我希望用户能够输入5:30并使倒数330秒。现在，对于用户而言，我必须写330秒而不是5:30。

   import UIKit

   class ViewController: UIViewController {

var enterTime = UITextField()
var lblTime = UILabel()
var startBTN = UIButton()
var timer = Timer()
var counter = 0

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view.

    [enterTime,lblTime,startBTN].forEach{
        $0.backgroundColor = .systemRed
        view.addSubview($0)
        $0.translatesAutoresizingMaskIntoConstraints = false
    }

    enterTime.frame = CGRect(x: view.center.x-115, y: view.center.y-200, width: 60, height: 50)
    lblTime.frame = CGRect(x: view.center.x-115, y: view.center.y, width: 60, height: 50)
    startBTN.frame = CGRect(x: view.center.x-115, y: view.center.y+200, width: 60, height: 50)

    startBTN.addTarget(self, action: #selector(startHit), for: .touchDown)

    enterTime.placeholder = String("MM:SS")


}



@objc func startHit() {
    timer.invalidate()
    if let counterText = enterTime.text, let counterValue = Int(counterText) {
        counter = counterValue
        lblTime.text = String(counter)
        timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(timerAction), userInfo: nil, repeats: true)
    }
}

@objc func timerAction() {
    counter -= 1
    lblTime.text = String(counter)
    if ( counter == 0 ) {
        timer.invalidate()
    }
}

}

Answer 1

您可以尝试

let str = "5:30"
let arr = str.components(separatedBy:":")
let fr = Int(arr.first!)!
let la = Int(arr.last!)!
count = fr * 60 + la // 330

要重新格式化

let lef = count / 60
let rig = count % 60
let res = "\(lef):\(rig)"

Answer 2

您可以通过两个函数来提取该功能，例如

apply plugin: 'com.android.application'

android {
    compileSdkVersion 29
    defaultConfig {
        applicationId "com.example.usub"
        minSdkVersion 26
        targetSdkVersion 29
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'androidx.appcompat:appcompat:1.2.0-alpha01'
    implementation 'com.firebase:geofire-android:2.1.2'
    implementation 'com.github.kmenager:material-animated-switch:1.2.2'
    implementation 'com.squareup.retrofit2:retrofit:2.7.0'
    implementation 'com.squareup.retrofit2:converter-scalars:2.7.0'
    implementation 'androidx.constraintlayout:constraintlayout:1.1.3'
    implementation 'com.google.firebase:firebase-database:19.2.0'
    implementation 'com.google.firebase:firebase-auth:19.2.0'
    implementation 'com.google.android.material:material:1.0.0'
    implementation 'com.github.d-max:spots-dialog:0.7@aar'
    implementation "androidx.cardview:cardview:1.0.0"
    implementation 'uk.co.chrisjenx:calligraphy:2.3.0'
    implementation 'com.rengwuxian.materialedittext:library:2.1.4'
    implementation 'com.google.android.gms:play-services-maps:17.0.0'
    //implementation 'com.google.android.gms:play-services:17.0.0'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'androidx.test.ext:junit:1.1.1'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.2.0'
    implementation 'com.google.firebase:firebase-analytics:17.2.1'
    implementation 'com.google.android.gms:play-services-location:17.0.0'
}


apply plugin: 'com.google.gms.google-services'

然后像使用它

// Formatting from displayed string to seconds
func convertToSeconds(from timeString: String) -> Int {
    let components = timeString.components(separatedBy: ":")
    if components.count == 2 {
        let minutes = Int(components[0]) ?? 0
        let seconds = Int(components[1]) ?? 0
        return (minutes * 60) + seconds
    } else if components.count == 3 {
        let hours = Int(components[0]) ?? 0
        let minutes = Int(components[1]) ?? 0
        let seconds = Int(components[2]) ?? 0
        return (hours * 60 * 60) + (minutes * 60) + seconds
    } else {
        return 0
    }
}

// Formatting from seconds to displayed string
func convertToTimestring(from seconds: Int) -> String {
    let formatter = DateComponentsFormatter()
    formatter.allowedUnits = [.hour, .minute, .second]
    formatter.unitsStyle = .positional
    let formattedString = formatter.string(from: TimeInterval(seconds))!
    return formattedString
}

或者还有几个小时

let timeSting = "03:30"
let seconds = convertToSeconds(from: timeSting)

所以您的let timeSting = "01:03:30" let seconds = convertToSeconds(from: timeSting)函数看起来像这样

hitStart

所以您的@objc func startHit() { timer.invalidate() counter = convertToSeconds(from: enterTime.text) timer = Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(timerAction), userInfo: nil, repeats: true) }函数看起来像这样

timerAction

如何使uitextfield从分钟和秒倒数

2 个答案: