viewWillAppear(_:) viewDidDisappear(_:) View SwiftUI

Question

我想从viewWillAppear(_:)上获取数据

SwiftUI中是否有任何相等的方法或修饰符可用 还有viewDidDisappear(_:)的任何修饰符

Answer 1

当然有

@available(iOS 13.0, OSX 10.15, tvOS 13.0, watchOS 6.0, *)
extension View {
/// Adds an action to perform when this view appears.
///
/// - Parameter action: The action to perform. If `action` is `nil`, the
///   call has no effect.
/// - Returns: A view that triggers `action` when this view appears.
@inlinable public func onAppear(perform action: (() -> Void)? = nil) -> some View

/// Adds an action to perform when this view disappears.
///
/// - Parameter action: The action to perform. If `action` is `nil`, the
///   call has no effect.
/// - Returns: A view that triggers `action` when this view disappears.
@inlinable public func onDisappear(perform action: (() -> Void)? = nil) -> some View
}