[英]ForEach TextField in SwiftUI
假设我有一个班级Student
class Student: Identifiable, ObservableObject {
var id = UUID()
@Published var name = ""
}
在另一个类(称为Class
)的 Array 中使用
class Class: Identifiable, ObservableObject {
var id = UUID()
@Published var name = ""
var students = [Student()]
}
在我的View
是这样定义的。
@ObservedObject var newClass = Class()
我的问题是:如何为每个Student
创建一个TextField
并将其与name
属性正确绑定(而不会出错)?
ForEach(self.newClass.students) { student in
TextField("Name", text: student.name)
}
现在,Xcode 向我抛出了这个:
Cannot convert value of type 'TextField<Text>' to closure result type '_'
我试过在调用变量之前添加一些$
s,但它似乎不起作用。
只需将@Published
更改为学生姓名属性的@State
。 @State
是为您提供带有$
前缀的Binding
的那个。
import SwiftUI
class Student: Identifiable, ObservableObject {
var id = UUID()
@State var name = ""
}
class Class: Identifiable, ObservableObject {
var id = UUID()
@Published var name = ""
var students = [Student()]
}
struct ContentView: View {
@ObservedObject var newClass = Class()
var body: some View {
Form {
ForEach(self.newClass.students) { student in
TextField("Name", text: student.$name) // note the $name here
}
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
一般来说,我还建议使用结构而不是类。
struct Student: Identifiable {
var id = UUID()
@State var name = ""
}
struct Class: Identifiable {
var id = UUID()
var name = ""
var students = [
Student(name: "Yo"),
Student(name: "Ya"),
]
}
struct ContentView: View {
@State private var newClass = Class()
var body: some View {
Form {
ForEach(self.newClass.students) { student in
TextField("Name", text: student.$name)
}
}
}
}
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.