[英]SwiftUI Insert a field name received from a function following "."
I get a field name from a function. How to insert that field name following dot "."我从 function 得到一个字段名。如何在点“.”之后插入该字段名。
struct User: Identifiable {
let username: String
let fullName: String
var description: String = ""
}
extension User {
func get_field_name(key: String?) -> String {
var default_field = ""
guard let key = key else { return default_field }
let field: [String: String] = [
"Name" : "fullName",
"Username" : "username",
"Bio" : "description"
]
return field[key] ?? default_field
}
}
Example if "item.title" is "Name" then例如,如果“item.title”是“Name”则
let user: User
Text(item.title) //OK - Name
Text(user.get_field_name(key: item.title)) //OK - fullName
Text(user.???) //??? How to insert field name following "."
I use it in the pic below我在下面的图片中使用它
Thank you so much for your answer.非常感谢您的回答。
I think you are looking for key paths.我认为您正在寻找关键路径。
Change get_field_name
to: get_field_name
更改为:
func getUserKeyPath(key: String?) -> KeyPath<User, String>? {
guard let key = key else { return nil }
let field: [_: KeyPath<User, _>] = [
"Name" : \.fullName,
"Username" : \.username,
"Bio" : \.description
]
return field[key]
}
Then you can do:然后你可以这样做:
if let keyPath = getFieldKeyPath(key: item.title) {
Text(user[keyPath: keyPath])
} else {
// handle the case when item.title does not match any property name in User
}
You can also do this in a single expression if you want to show a default string in the Text
when item.title
does not match any property name:如果您想在
item.title
与任何属性名称不匹配时在Text
中显示默认字符串,您也可以在单个表达式中执行此操作:
Text(getFieldKeyPath(key: "Name").map { user[keyPath: $0] } ?? "Unknown")
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.