swiftui - 实例成员不能用于 SwiftUI Preview 中的类型

Question

我的预览中出现以下错误：

struct DetailView: View {
    var header: DataProvider.DataHeader

    var body: some View {
        Text("...")
    }
}

struct DetailView_Previews: PreviewProvider {
    var a = DataProvider.DataHeader(title: "a", text: "b")

    static var previews: some View {
        DetailView(header: a)
    }
}

错误是：

Instance member 'a' cannot be used on type 'DetailView_Previews'

为什么会这样？

标签： swiftuipreview

Answer 1

这是由于static var preview，

所以也使用静态的

static var a = DataProvider.DataHeader(title: "a", text: "b")

或就地建造

DetailView(header: DataProvider.DataHeader(title: "a", text: "b"))