ios 如何在 Swift 中将日期转换为字符串
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How to convert Date to String in Swift
提问by John Martin
I'm trying to call a function one argument is current time and Date and other is a file name, They both are strings. How can I convert Date()to a string. I tried:
我试图调用一个函数，一个参数是当前时间和日期，另一个是文件名，它们都是字符串。如何转换Date()为字符串。我试过：
writeToFile(content: Date(), fileName: "jm.txt")
but it gave me error:
但它给了我错误：
Cannot convert value of type 'Date' to expected argument type 'String'
无法将“日期”类型的值转换为预期的参数类型“字符串”
回答by Yimin Rong
Something like this:
像这样的东西：
let df = DateFormatter()
df.dateFormat = "yyyy-MM-dd hh:mm:ss"
let now = df.stringFromDate(Date())
writeToFile(content: now, fileName: "jm.txt")
回答by Danziger
You need to use DateFormatterfor that:
您需要为此使用DateFormatter：
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd"
writeToFile(content: formatter.string(from: Date()), fileName: "jm.txt")
