如何將可選類型綁定到非可選類型

Question

Xcode 說無法將“Binding<String?>”類型的值轉換為預期的參數類型“Binding<String>”

struct CustomContentView: View {
    @State var queryItem = URLQueryItem.init(name: "key", value: nil)

    var body: some View {
//queryItem.value is optional string👇
        TextField.init("value", text: $queryItem.value)
//👆Cannot convert value of type 'Binding<String?>' to expected argument type 'Binding<String>'
    }
}

截屏

Answer 1

使用以下

var body: some View {
    TextField("url", text: Binding(
        get: { self.queryItem.value ?? ""},
        set: { self.queryItem.value = $0 } )
    )
}