Question

My project contains the JSON file 'LocationsData.json'

An error is displayed 'Cannot find 'LocationsData' in scope'

（（如果需要-以下代码包含在我的'Data.swift'文件中，这是'SearchRedirect.swift'中的var'locationsDataTypes'所引用的）

import UIKit
import SwiftUI
import CoreLocation

let locationsDataTypes: [LocationsDataTypes] = load("LocationsData.json")

func load<T: Decodable>(_ filename: String) -> T {
let data: Data

guard let file = Bundle.main.url(forResource: filename, withExtension: nil)
    else {
        fatalError("Couldn't find \(filename) in main bundle.")
}

do {
    data = try Data(contentsOf: file)
} catch {
    fatalError("Couldn't load \(filename) from main bundle:\n\(error)")
}

do {
    let decoder = JSONDecoder()
    return try decoder.decode(T.self, from: data)
} catch {
    fatalError("Couldn't parse \(filename) as \(T.self):\n\(error)")
}
}

final class ImageStore {
typealias _ImageDictionary = [String: CGImage]
fileprivate var images: _ImageDictionary = [:]

fileprivate static var scale = 2

static var shared = ImageStore()

func image(name: String) -> Image {
    let index = _guaranteeImage(name: name)
    
    return Image(images.values[index], scale: CGFloat(ImageStore.scale), label: Text(name))
}

static func loadImage(name: String) -> CGImage {
    guard
        let url = Bundle.main.url(forResource: name, withExtension: "jpg"),
        let imageSource = CGImageSourceCreateWithURL(url as NSURL, nil),
        let image = CGImageSourceCreateImageAtIndex(imageSource, 0, nil)
    else {
        fatalError("Couldn't load image \(name).jpg from main bundle.")
    }
    return image
}

fileprivate func _guaranteeImage(name: String) -> _ImageDictionary.Index {
    if let index = images.index(forKey: name) { return index }
    
    images[name] = ImageStore.loadImage(name: name)
    return images.index(forKey: name)!
}
}

Answer 1

正如pawello2222所暗示的，locationsData并未在任何地方声明。

我怀疑您的List视图构建器函数编写不正确。

代替这个...

List(LocationsData, id: \.id) { locationsDataTypes in

尝试以下操作...

List(locationsDataTypes, id: \.id) { locationsData in
    ...
                Image(locationsData.imageName)
                    .resizable
    ...
}

locationsDataTypes是集合，在您的情况下，LocationsDataTypes和locationsData的数组是该集合中每次迭代的单个实例。

此外，在堆栈溢出中编写问题时，最佳实践是将相关代码包含在问题中的代码块中，而不是通过超链接访问。造成这种情况的原因很多，这里有几个...

SO社区可以更轻松地将代码复制并粘贴到其解决方案中，作为其响应的一部分，从而节省了我们很多时间；
链接中断，使您的问题无处可寻，将来可能遇到相同问题的任何人。

在范围内找不到“ LocationsData”

1 个答案: