将JSON（日期）解析为Swift

本文介绍了将JSON（日期）解析为Swift的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我在Swift中的应用程序中返回了JSON，并且有一个字段可以返回给我一个日期。当我参考这些数据时，代码给了我类似/ Date（1420420409680）/的内容。如何将其转换为NSDate？在Swift中，我已经使用Objective-C测试了示例，但没有成功。

I have a return JSON in my application in Swift, and have a field that returns me a date. When I refer to this data, the code gives me something like "/ Date (1420420409680) /". How do I convert this into NSDate? In Swift, please, I´ve tested examples with Objective-C, without success.

推荐答案

这看起来与JSON非常相似编码Microsoft的ASP.NET AJAX使用的日期，其中在 JavaScript和.NET中的JavaScript对象表示法（JSON）简介：

That looks very similar to the JSON encoding for a date as used by Microsoft's ASP.NET AJAX, which is described in An Introduction to JavaScript Object Notation (JSON) in JavaScript and .NET:

例如，Microsoft的ASP .NET AJAX既不使用所描述的约定。相反，它将.NET DateTime值编码为JSON字符串，其中字符串的内容为/ Date（ticks）/，其中ticks 表示自纪元（UTC）以来的毫秒数。所以1989年11月29日， 4:55:30 AM，UTC编码为\ / Date（628318530718）\ /\".

For example, Microsoft's ASP.NET AJAX uses neither of the described conventions. Rather, it encodes .NET DateTime values as a JSON string, where the content of the string is /Date(ticks)/ and where ticks represents milliseconds since epoch (UTC). So November 29, 1989, 4:55:30 AM, in UTC is encoded as "\/Date(628318530718)\/".

唯一的区别是您的格式为 /日期（刻度）/ 而不是 \ / Date（ticks）\ / 。

The only difference is that you have the format /Date(ticks)/ and not \/Date(ticks)\/.

您必须提取括号之间的数字。将其除以1000 得出自1970年1月1日以来的秒数。

You have to extract the number between the parentheses. Dividing that by 1000 gives the number in seconds since 1 January 1970.

以下代码显示了如何做到这一点。对于 NSDate ，它实现为afailable convenience initializer：

The following code shows how that could be done. It is implemented as a "failable convenience initializer" for NSDate:

extension NSDate { convenience init?(jsonDate: String) { let prefix = "/Date(" let suffix = ")/" // Check for correct format: if jsonDate.hasPrefix(prefix) && jsonDate.hasSuffix(suffix) { // Extract the number as a string: let from = jsonDate.startIndex.advancedBy(prefix.characters.count) let to = jsonDate.endIndex.advancedBy(-suffix.characters.count) // Convert milliseconds to double guard let milliSeconds = Double(jsonDate[from ..< to]) else { return nil } // Create NSDate with this UNIX timestamp self.init(timeIntervalSince1970: milliSeconds/1000.0) } else { return nil } } }

示例用法（包含日期字符串）：

Example usage (with your date string):

if let theDate = NSDate(jsonDate: "/Date(1420420409680)/") { print(theDate) } else { print("wrong format") }

这给出了输出

2015-01-05 01:13:29 +0000

Swift 3更新（Xcode 8）：

extension Date { init?(jsonDate: String) { let prefix = "/Date(" let suffix = ")/" // Check for correct format: guard jsonDate.hasPrefix(prefix) && jsonDate.hasSuffix(suffix) else { return nil } // Extract the number as a string: let from = jsonDate.index(jsonDate.startIndex, offsetBy: prefix.characters.count) let to = jsonDate.index(jsonDate.endIndex, offsetBy: -suffix.characters.count) // Convert milliseconds to double guard let milliSeconds = Double(jsonDate[from ..< to]) else { return nil } // Create NSDate with this UNIX timestamp self.init(timeIntervalSince1970: milliSeconds/1000.0) } }

示例：

if let theDate = Date(jsonDate: "/Date(1420420409680)/") { print(theDate) } else { print("wrong format") }