加载本地 json 文件时更新时间超过 5 秒

Question

我试图从本地 json 文件加载一些数据，但它一直显示

"PreviewUpdateTimedOutError: Updating took more than 5 seconds

这让我可以恢复了canvas。我不知道我的结构中的错误是什么。 json.file 从 api

下载

我的加载json函数：

func loadJsonData() -> [Movie] {
    let filename : String="data.json"
    guard let url = Bundle.main.url(forResource: filename, withExtension: nil)else{
        fatalError("no file found")}
    guard let data = try? Data(contentsOf: url) else {
        fatalError("can't load") }
    guard let list = try? JSONDecoder().decode(movieData.self, from: data) else {
        fatalError("no file found") }
    return list.result
}

我的结构文件：

struct movieData:Codable {
    var result:[Movie]
}
struct Movie:Codable,Identifiable{
    var adult:Bool
    var backdrop_path:String
    var genre_ids:[Int]
    var id:Int
    var original_language:String
    var original_title:String
    var overview:String
    var popularity:Double
    var poster_path:String?
    var release_data:String
    var title:String?
    var video:Bool
    var vote_average:Double?
    var vote_count:Int
}

我的data.json


{
       "result": [
            {
                "adult": false,
                "backdrop_path": "/yizL4cEKsVvl17Wc1mGEIrQtM2F.jpg",
                "genre_ids": [
                    28,
                    878,
                    12
                ],
                "id": 588228,
                "original_language": "en",
                "original_title": "The Tomorrow War",
                "overview": "The world is stunned when a group of time travelers arrive from the year 2051 to deliver an urgent message: Thirty years in the future, mankind is losing a global war against a deadly alien species. The only hope for survival is for soldiers and civilians from the present to be transported to the future and join the fight. Among those recruited is high school teacher and family man Dan Forester. Determined to save the world for his young daughter, Dan teams up with a brilliant scientist and his estranged father in a desperate quest to rewrite the fate of the planet.",
                "popularity": 3368.737,
                "poster_path": "/34nDCQZwaEvsy4CFO5hkGRFDCVU.jpg",
                "release_date": "2021-09-03",
                "title": "The Tomorrow War",
                "video": false,
                "vote_average": 7.8,
                "vote_count": 271
            },
}

我的内容视图


import SwiftUI

struct HomeView: View {
    let moviedata: movieData
    let movies:[Movie]
    init(){
        self.moviedata = movieData(result: loadJsonData())
        movies=self.moviedata.result
    }
  
    var body: some View {
        
       Text("hello!?")
        
    }

}

struct HomeView_Previews: PreviewProvider {
    static var previews: some View {
        HomeView()
    }
}

Answer 1

在您的 struct Movie 更改中

var release_data:String

至

var release_date:String

Answer 2

解码器在 guard 语句中发送致命错误，因为您的 json 文件在数组末尾丢失 ]，导致视图崩溃。

并且在书中结构中将 releaseData 更改为 releaseDate

var releaseData : String

到

var releaseDate : String

data.json :

{
"result":
[
    {
        "adult": false,
        "backdrop_path": "/yizL4cEKsVvl17Wc1mGEIrQtM2F.jpg",
        "genre_ids": [
            28,
            878,
            12
        ],
        "id": 588228,
        "original_language": "en",
        "original_title": "The Tomorrow War",
        "overview": "The world is stunned when a group of time travelers arrive from the year 2051 to deliver an urgent message: Thirty years in the future, mankind is losing a global war against a deadly alien species. The only hope for survival is for soldiers and civilians from the present to be transported to the future and join the fight. Among those recruited is high school teacher and family man Dan Forester. Determined to save the world for his young daughter, Dan teams up with a brilliant scientist and his estranged father in a desperate quest to rewrite the fate of the planet.",
        "popularity": 3368.737,
        "poster_path": "/34nDCQZwaEvsy4CFO5hkGRFDCVU.jpg",
        "release_date": "2021-09-03",
        "title": "The Tomorrow War",
        "video": false,
        "vote_average": 7.8,
        "vote_count": 271
    }
]}

加载本地 json 文件时更新时间超过 5 秒

Updating took more than 5 seconds when loading local json file

json

compiler-errors

ios

swift

swiftui