[英]Missing argument for parameter 'message' in call
I'm back with another question.我带着另一个问题回来了。 I was following this guide: https://medium.com/@fs.dolphin/passing-data-between-views-in-swiftui-793817bba7b1我正在关注本指南: https://medium.com/@fs.dolphin/passing-data-between-views-in-swiftui-793817bba7b1
Everything worked from it, but the SecondView_Previews is throwing an error Missing argument for parameter 'message' in call
.一切正常,但 SecondView_Previews Missing argument for parameter 'message' in call
。 Here is my ContentView and SecondView这是我的 ContentView 和 SecondView
// ContentView
import SwiftUI
struct ContentView: View {
@State private var showSecondView = false
@State var message = "Hello from ContentView"
var body: some View {
VStack {
Button(action: {
self.showSecondView.toggle()
}){
Text("Go to Second View")
}.sheet(isPresented: $showSecondView){
SecondView(message: self.message)
}
Button(action: {
self.message = "hi"
}) {
Text("click me")
}
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
import SwiftUI
struct SecondView: View {
@State var message: String
var body: some View {
Text("\(message)")
}
}
struct SecondView_Previews: PreviewProvider {
static var previews: some View {
SecondView() // Error here: Missing argument for parameter 'message' in call.
}
}
It tried changing it to SecondView(message: String) and the error changes to "Cannot convert value of type 'String.Type' to expected argument type 'String'"它尝试将其更改为 SecondView(message: String) 并将错误更改为“无法将'String.Type'类型的值转换为预期的参数类型'String'”
Can someone please explain what I'm doing wrong, or how to correctly set up the preview.有人可以解释我做错了什么,或者如何正确设置预览。 It all works fine when there's no preview.没有预览时一切正常。 Thanks in advance!提前致谢!
struct ContentView: View {
@State var message: String //Define type here
var body: some View {
Text("\(message)")
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView(message: "Some text") //Passing value here
}
}
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