Question

假设我想显示一个字符串，具体取决于它的日期。例如，如果它是2016-12-24我想要字符串＆＃34;圣诞快乐＆＃34;要显示或如果它是2017-01-01我想要文本＆＃34;新年快乐＆＃34;。

这是我到目前为止所得到的，但我不知道如何添加字符串并将其连接到标签。

    let now = NSDate()
print(now)
now.timeIntervalSinceReferenceDate

// March 10, 1876 was 3,938,698,800 seconds before the third millennium (January 1, 2001 midnight UTC)
let firstLandPhoneCallDate = NSDate(timeIntervalSinceReferenceDate: -3_938_698_800.0)

// April 3, 1973 was 875,646,000 seconds before the third millennium
let firstCellPhoneCallDate = NSDate(timeIntervalSinceReferenceDate: -875_646_000.0)

// January 9, 2007, 18:00 UTC was 190,058,400 seconds after the third millennium
let iPhoneAnnouncementDate = NSDate(timeIntervalSinceReferenceDate: 190_058_400.0)

// January 27, 2010, 18:00 UTC was 286,308,000 seconds after the third millennium
let iPadAnnouncementDate = NSDate(timeIntervalSinceReferenceDate: 286_308_000.0)

Answer 1

我建议你有一个包含日期和事件名称的字典或数据库。在这个例子中，我将使用简单的dict，如：

let eventsCalendar: Dictionary<String, String> = [
"0101": "Happpy New Year!",
//... other dates and events
]

在这个例子中，我使用字符串，但日期可以是NSDate。然后将今天的NSDate变成字符串，如：

func todaysDateAsString() -> String {

    let date = NSDate()
    let dateFormatter = NSDateFormatter()
    dateFormatter.dateFormat = "MMdd"
    let str = dateFormatter.stringFromDate(date)
    return str
}

最后，将字典中的相关内容分配到您的标签Outlet（您可以将标签拖放到ViewController代码窗口并创建一个插座名称（不是动作，而是插座）。调用它，标签然后使用方法那个标签 - label.text

func todaysEventString(dateString: String) -> String {
    return eventsCalendar[dateString]!
}

label.text = todaysEventString(todaysDateAsString())

今天仅使用月份和日期。如果您有多年不同的事件，则在数据库中包含一年，并在dateformatter.dateFormat中使用year。在你的情况下：

func DateAsString() -> String {

    let date = NSDate()
    let dateFormatter = NSDateFormatter()
    dateFormatter.dateFormat = "yyyy-MM-dd"
    let str = dateFormatter.stringFromDate(date)
    return str
}

数据库以yyyy-MM-dd格式保存密钥：

 "1992-01-22": "Somebody's Birthday",

Answer 2

在这里，这非常有效：

//
//  ViewController.swift
//  temp
//
//  Created by thinkswift on 12.01.16.
//  Copyright © 2016. thinkswift. All rights reserved.
//

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var myLabel: UILabel!

    let eventsCalendar: Dictionary<String, String> = [
        "1992-01-22": "Somebody's Birthday",
        "2016-01-12": "Johns Birthday"
        //... other dates and events
    ]

    func DateAsString() -> String {

        let date = NSDate()
        let dateFormatter = NSDateFormatter()
        dateFormatter.dateFormat = "yyyy-MM-dd"
        let str = dateFormatter.stringFromDate(date)
        return str
    }

    func todaysEventString(dateString: String) -> String {
        return eventsCalendar[dateString]!
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
        myLabel.text = todaysEventString(DateAsString())
    }

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


}

Answer 3

导入UIKit

类ViewController：UIViewController {

@IBOutlet weak var label: UILabel!

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.
}

let eventsCalendar: Dictionary<String, String> = [
    "1992-01-22": "Somebody's Birthday",
    //... other dates and events
]

func DateAsString() -> String {

    let date = NSDate()
    let dateFormatter = NSDateFormatter()
    dateFormatter.dateFormat = "yyyy-MM-dd"
    let str = dateFormatter.stringFromDate(date)
    return str
}

func todaysEventString(dateString: String) -> String {
    return eventsCalendar[dateString]!
}

label.text = todaysEventString(todaysDateAsString())

}

Answer 4

Swift 3.0更新 - 适用于Xcode 8.02

 let date = NSDate()
 let formatter = DateFormatter()
 formatter.dateFormat = "M/dd/yyyy" // Set the way the date should be displayed
 dateLabel.text = formatter.string(from: date as Date)

根据swift中的日期显示标签

4 个答案: