Instance Method インスタンスメソッド

focused(_:equals:)

Modifies this view by binding its focus state to the given state value.

Declaration 宣言

func focused<Value>(_ binding: FocusState<Value>.Binding, equals value: Value) -> some View where Value : Hashable

Return Value 戻り値

The modified view.

Parameters パラメータ

binding: The state binding to register. When focus moves to the modified view, the binding sets the bound value to the corresponding match value. If a caller sets the state value programmatically to the matching value, then focus moves to the modified view. When focus leaves the modified view, the binding sets the bound value to nil. If a caller sets the value to nil, SwiftUI automatically dismisses focus.
value: The value to match against when determining whether the binding should change.

Discussion 議論

Use this modifier to cause the view to receive focus whenever the the binding equals the value. Typically, you create an enumeration of fields that may receive focus, bind an instance of this enumeration, and assign its cases to focusable views.

The following example uses the cases of a LoginForm enumeration to bind the focus state of two TextField views. A sign-in button validates the fields and sets the bound focusedField value to any field that requires the user to correct a problem.

struct LoginForm {
    enum Field: Hashable {
        case usernameField
        case passwordField
    }


    @State private var username = ""
    @State private var password = ""
    @FocusState private var focusedField: Field?


    var body: some View {
        Form {
            TextField("Username", text: $username)
                .focused($focusedField, equals: .usernameField)


            SecureField("Password", text: $password)
                .focused($focusedField, equals: .passwordField)


            Button("Sign In") {
                if username.isEmpty {
                    focusedField = .usernameField
                } else if password.isEmpty {
                    focusedField = .passwordField
                } else {
                    handleLogin(username, password)
                }
            }
        }
    }
}

To control focus using a Boolean, use the focused(_:) method instead.