SwiftUI 视图和 Swift 包管理器

问题描述：

我正在尝试创建一个基本上是单个 SwiftUI 视图的 Swift 包.我在这里创建了一个示例来显示正在发生的事情.打包做什么，并不重要，我只是在视图中包含了一些 @State 和 @Binding 变量，这样我就会得到与我在真实包中得到的相同的错误.视图结构是这样的.

I am trying to create a Swift Package that is basically a single SwiftUI View. I have created a sample here to display what is happening. What the packaged does, doesn't matter, I have just included some @State and @Binding variables in the View so that I get the same error I get in my real package. The View struct is this.

import SwiftUI

public struct SampleView: View {
    @Binding var myNum:Int
    @State var fixedText:String = ""
    var myText = ""
    var optional: String?


   public  var body: some View {
        VStack {
            if optional != nil {
                Text(optional!)
            }
            Text(myText)
            Text("Parent number: \(myNum)")
            Text("\(fixedText)")
            Button("Increment num") {
                self.myNum += 1
            }.foregroundColor(.blue)
            Button("Change Parent Text") {
                self.fixedText = "Only Changes Child"
            }.foregroundColor(.blue)
        }.background(Color.red)
            .foregroundColor(.white)
    }
}

当我添加包并将其导入到我的项目中的一个视图中时，如果视图不是 Swift 包的一部分，我应该能够像这样使用 Do like this:

When I add the package and import it into one of the views in my project, I should be able to use Do something like this as I can do if the View is not part of a Swift Package:

 SampleView(myNum: $myNum,
             fixedText: parentText,
             myText: "Display Text Passed from parent")

但是，我没有得到代码完成并且出现错误:

However, I get no code completion and I get the error:

'SampleView' initializer is inaccessible due to 'internal' protection level

我在 SampeView 结构上尝试了各种初始化，但不断收到各种不同的错误.我只是不明白如何在这里修复访问级别.任何人都可以帮忙吗?截图也在这里.

I have tried all sorts of initializations on the SampeView struct, but keep getting all sorts of different errors. I just don't understand how to fix the access levels here. Can anyone help? Screenshot is here also.

答

这里是 Package 中的预期声明(使用 Xcode 11.2.1/iOS 13.2.2 测试).请注意，@State 不允许在 View 之外使用，因此您需要同步的所有内容都应通过 Binding 传递:

Here is expected declaration in Package (tested with Xcode 11.2.1 / iOS 13.2.2). Please note that @State are not allowed to be used outside of View, so all you need to make in sync should be passed via Binding:

public struct SampleView: View {
    @Binding var myNum:Int
    @Binding var fixedText:String
    var myText: String
    var optional: String?

    public init(myNum: Binding<Int>, fixedText: Binding<String>, 
                myText: String = "", optional: String? = nil) {
        self._myNum = myNum
        self._fixedText = fixedText
        self.myText = myText
        self.optional = optional
    }

    public var body: some View {
        VStack {
            if optional != nil {
                Text(optional!)
            }
            Text(myText)
            Text("Parent number: \(myNum)")
            Text("\(fixedText)")
            Button("Increment num") {
                self.myNum += 1
            }.foregroundColor(.blue)
            Button("Change Parent Text") {
                self.fixedText = "Only Changes Child"
            }.foregroundColor(.blue)
        }.background(Color.red)
            .foregroundColor(.white)
    }
}

和用法:

@State private var myNum: Int = 1
@State private var parentText = "Test"
var body: some View {
    SampleView(myNum: $myNum,
               fixedText: $parentText,
               myText: "Display Text Passed from parent")
}

SwiftUI 视图和 Swift 包管理器

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