在SwiftUI中显示一个空视图 [英] Displaying an empty view in SwiftUI

问题描述

在SwiftUI中，经常需要根据某些条件显示空"视图，例如:

In SwiftUI there's frequently a need to display an "empty" view based on some condition, e.g.:

struct OptionalText: View {
  let text: String?

  var body: some View {
    guard let text = text else { return }

    return Text(text) 
  }
}

不幸的是，由于 guard 的正文必须返回某些视图，因此该代码无法编译，当 text 为 nil <时，该视图为空"视图/code>.当 text 为 nil 时，应如何重写此示例，以便编译并呈现空"视图?

Unfortunately, this doesn't compile since the body of guard has to return some view, that is an "empty" view when text is nil. How should this example be rewritten so that it compiles and renders an "empty" view when text is nil?

推荐答案

您必须返回一些内容.如果在某些情况下您不希望显示任何内容，请显示"一个... EmptyView ;)

You have to return something. If there is some condition where you want to display nothing, "display" an...EmptyView ;)

var body: some View {
    Group {
        if text != nil {
            Text(text!)
        } else {
            EmptyView()
        }
    }
}

SwiftUI DSL将要求您将if/else包装在 Group 中，并且DSL没有保护/如果让其命名.

The SwiftUI DSL will require you to wrap the if/else in a Group and the DSL has no guard/if let nomenclature.

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