My code: I use onCommit closure to be able to perform an action by pressing the Enter key when the TextField is being focused.
import SwiftUI
struct ContentView: View {
@State private var text = ""
var body: some View {
TabView {
TextField(
"",
text: $text,
onCommit: { print("onCommit") } // I have a problem here
)
.tabItem {
Text("Tab 1")
}
Text("Tab 2")
.tabItem {
Text("Tab 2")
}
Text("Tab 3")
.tabItem {
Text("Tab 3")
}
}
}
}
My problem: The onCommit closure is also always triggered when I switch to another tab, making my App perform an unexpected action.
My questions:
This is the bug or the feature?
Is there any other way to perform an action by pressing Enter key?
Duong_Thai
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I notice that this pattern shows up quite frequently in the Swift world but I don't know what its name is.
define a new type that conforms to a protocol
solely use the new type as a unique value to create a new "thing"
extension VerticalAlignment {
struct CustomAlignment: AlignmentID {...}
static let customAlignment = VerticalAlignment(CustomAlignment.self)
}
Please help me understand this section!
I'm reading Finding the Dynamic Type in a Generic Context that has this snippet:
func printGenericInfo<T>(_ value: T) {
let t = type(of: value)
print("'\(value)' of type '\(t)'")
}
protocol P {}
extension String: P {}
let stringAsP: P = "Hello!"
printGenericInfo(stringAsP)
// 'Hello!' of type 'P'
... that's followed up by this sentence:
This unexpected result occurs because the call to type(of: value) inside printGenericInfo(_:) must return a metatype that is an instance of T.Type , but String.self (the expected dynamic type) is not an instance of P.Type (the concrete metatype of value).
1. How come String.self is not an instance of P when I can run this code?
func f(_ t: P.Type) { print("...") }
f(String.self)
2. Why does type(of:) return the concrete metatype outside but not inside generic functions?
print("'\(stringAsP)' of type '\(type(of: stringAsP))'")
// 'Hello!' of type 'String'