如何在SwiftUI中正确使用NavigationLink

全新的编码器和第一次使用。如果这对大多数人来说太容易了，我道歉。我在使用naviationLink从上下文视图切换到详细视图时遇到问题。我想显示一排吉他，然后显示从表中选择的吉他的详细视图

这里有一些细节。我有一个Guitars.swift文件，其中包含吉他列表。（见下文）

我有一个包含已定义属性和结构的GuitardDetails文件。（见下文）

---

我得到的错误是：“'GuitarDetails.Type'不能转换为”（Guitars）->GuitarDetails'

你需要传递你的

吉他数组，而不是
列表中的
吉他类型。这就是为什么你会得到这个错误

虽然您的命名不好，但您使用复数表示单数项，单数表示复数项。这可能会导致混淆，最好使用适当的术语来描述您所描述的内容

例如，您的
Guitars
结构只描述了一把吉他，因此它实际上应该被重命名为
Guitars
。类似地，吉他数组被命名为
Guitars
，这没有意义，因为它是一个吉他数组，所以它应该是复数，并被命名为
Guitars

理想情况下，您应该有这样的东西；注意，我使用了更合适的命名约定

struct Guitar: Identifiable, Hashable {
    let id: Int
    let name, description, imageName: String
}

// defining guitars like this, outside of a class or struct, makes it a global variable.
let guitars: [Guitar] = [
     .init (id: 1, name: "Classical", description: "This is a nylon string guitar that is acoustic and made if cedar or spruce wood", imageName: "classical"),
     .init (id: 2, name: "Acoustic", description: "The acoustic guitar is a steel string instrument that is traditionally played as an accompanying part of a musical performance.", imageName: "acoustic"),
     .init (id: 3, name: "Electric", description: "This is a steel string guitar that is electic with pickups and made to be played through amplifiers", imageName: "electric_guitar-1"),
     .init (id: 4, name: "Banjo", description: "This is a steel string guitar that has five strings.  It's usually played in country and bluegrass music", imageName: "banjo"),
     .init (id: 5, name: "Bass", description: "This is a steel string guitar that has four strings.  It's usually played in all types of bands and provides the bass line for the music", imageName: "bass")
]

然后，您的
吉他尾部应该与此类似：

struct GuitarDetail: View {

    var selectedGuitar: Guitar // notice it is no longer plural, as that didn't make sense

    var body: some View {
        VStack{
            Image(selectedGuitar.imageName) // make sure you use the image name
            .resizable()
            .frame(width:300, height: 300)
            VStack {
                Spacer()

            }
        }
    }
}

最后是您的
ContentView

struct ContentView: View {
    var body: some View {
        NavigationView {
            // as you have defined guitars above as a global variable you should be able to access it like this
            List (guitars) { guitar in
                NavigationLink(destination: GuitarDetail(selectedGuitar: guitar) {
                    Text(guitar.name) // you need something inside your NavigationLink for it to work
           }
        }
    }
}

谢谢你的帮助。我非常感谢。现在我的吉他细节文件中的预览结构在狂吠。有一个占位符，但我不确定它期望什么。它以前没有这样做。你能告诉我它期望什么，这样我就可以运行代码吗？struct Guitardeails\u预览：预览提供程序{静态变量预览：一些视图{GuitarDetails（selectedGuitar:Guitar）。错误是源文件中的编辑器占位符。您需要传入
Guitar
对象。只需传入
guitars[0]
就可以了，我试过了，它仍然显示相同的错误。GuitarDetails（selectedGuitar:Guitar[0]）。我还用吉他[0]试过它它给了我一个关于未解析标识符guitars的错误。这很难。这取决于您所做的更改，您需要确保所有内容都正确命名。在我的代码版本中，
guitars[0]
起作用，或者您可以创建一个
Guitar
的实例并将其传入
Guitar（id:1，名称：“古典”，描述：“这是一把尼龙弦吉他，是原声吉他，由雪松或云杉木制成”，imageName:“古典”）
好的。我会设法弄清楚的。再次感谢您的帮助。
struct Guitar: Identifiable, Hashable {
    let id: Int
    let name, description, imageName: String
}

// defining guitars like this, outside of a class or struct, makes it a global variable.
let guitars: [Guitar] = [
     .init (id: 1, name: "Classical", description: "This is a nylon string guitar that is acoustic and made if cedar or spruce wood", imageName: "classical"),
     .init (id: 2, name: "Acoustic", description: "The acoustic guitar is a steel string instrument that is traditionally played as an accompanying part of a musical performance.", imageName: "acoustic"),
     .init (id: 3, name: "Electric", description: "This is a steel string guitar that is electic with pickups and made to be played through amplifiers", imageName: "electric_guitar-1"),
     .init (id: 4, name: "Banjo", description: "This is a steel string guitar that has five strings.  It's usually played in country and bluegrass music", imageName: "banjo"),
     .init (id: 5, name: "Bass", description: "This is a steel string guitar that has four strings.  It's usually played in all types of bands and provides the bass line for the music", imageName: "bass")
]

struct GuitarDetail: View {

    var selectedGuitar: Guitar // notice it is no longer plural, as that didn't make sense

    var body: some View {
        VStack{
            Image(selectedGuitar.imageName) // make sure you use the image name
            .resizable()
            .frame(width:300, height: 300)
            VStack {
                Spacer()

            }
        }
    }
}

struct ContentView: View {
    var body: some View {
        NavigationView {
            // as you have defined guitars above as a global variable you should be able to access it like this
            List (guitars) { guitar in
                NavigationLink(destination: GuitarDetail(selectedGuitar: guitar) {
                    Text(guitar.name) // you need something inside your NavigationLink for it to work
           }
        }
    }
}