swift - 如何从 userNotificationCenter 中读取内容 - Swift

Question

如何读取“magazin”的值？

func userNotificationCenter(_ center: UNUserNotificationCenter, didReceive response: UNNotificationResponse, withCompletionHandler completionHandler: @escaping () -> Void) {
        let action = response.actionIdentifier
        let request = response.notification.request
        let userInfo = request.content.userInfo

        if action == "open.magazin" {
            var str: String?
            let magazin = userInfo["magazin"]
            print("MAGAZYN : \(magazin)")

        }
        completionHandler()
 }

函数返回值:

MAGAZYN : Optional({"pages":100,"size":"50 MB","productId":"com.sad","purchased":false,"coverImageURL":"","cat":3,"itemPrice":"4,99","fileURL":"","id":5,"title":"test","demoStartPage":0,"desc":""})

Answer 1

Swift 4 提供了非常强大的开箱即用的 JSON 解析。我最喜欢的博客是 Ultimate Guide to JSON Parsing with Swift 4 ，因为我做的不够频繁，而且它以一种简单的方式涵盖了许多“陷阱”。

所以，我拿了你的数据，把它扔到 Playground 上，然后用...

let userInfo: [AnyHashable: Any] = ["magazin": "{\"pages\":100,\"size\":\"50 MB\",\"productId\":\"com.sad\",\"purchased\":false,\"coverImageURL\":\"\",\"cat\":3,\"itemPrice\":\"4,99\",\"fileURL\":\"\",\"id\":5,\"title\":\"test\",\"demoStartPage\":0,\"desc\":\"\"}"]

struct Magazin: Codable {
    let pages: Int
    let size: String
    let productId: String
    let purchased: Bool
    let coverImageURL: String
    let cat: Int
    let itemPrice: String
    let fileURL: String
    let id: Int
    let title: String
    let demoStartPage: Int
    let desc: String
}

if let magazin = userInfo["magazin"] as? String {
    let jsonData = magazin.data(using: .utf8)!
    let decoder = JSONDecoder()
    let mag = try! decoder.decode(Magazin.self, from: jsonData)
    print(mag.pages)
    print(mag.size)
    print(mag.productId)
    print(mag.purchased)
    print(mag.coverImageURL)
    print(mag.cat)
    print(mag.itemPrice)
    print(mag.fileURL)
    print(mag.id)
    print(mag.title)
    print(mag.demoStartPage)
    print(mag.desc)
}

即将输出

100
50 MB
com.sad
false

3
4,99

5
test
0

注意 我在上面的例子中使用了强制解包，我希望你清理它并适当使用 guard 和 do-catch

I can not cope with this message: "Can not convert value of type 'Any?' to expected argument type 'Data' "

所以，有两件事，userInfo 是一个 [AnyHasable: Any] 风格的字典，所以您需要做的第一件事就是将值转换为合适的类型，根据您的示例，这可能是一个 String...

if let magazin = userInfo["magazin"] as? String {
    //...
}

接下来，您需要将String 转换为Data

if let jsonData = magazin.data(using: .utf8) {
    //...
}