如果有人还在寻找如何在 SwiftUI 中执行此操作。我做了一个package named NavigationBarLargeTitleItems 来处理这个问题。它模仿了您在 AppStore 和 Messages-app 中看到的行为。
在此示例中，您将看到一个配置文件图标，但您也可以使用创建食谱按钮等文本。如果您想让它在滚动后立即显示为标准导航栏项目，则需要 GeometryReader。如果您喜欢示例，请告诉我。
请注意，为了能够完成此行为，我们需要将其添加到私有类“_UINavigationBarLargeTitleView”中，因此在提交到 App Store 时可能会导致您的应用被拒绝。
我还在这里为那些不喜欢链接或只想复制/粘贴的人提供完整的相关源代码。
扩展：
// Copyright © 2020 Mark van Wijnen
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the “Software”), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
import SwiftUI
public extension View {
func navigationBarLargeTitleItems<L>(trailing: L) -> some View where L : View {
overlay(NavigationBarLargeTitleItems(trailing: trailing).frame(width: 0, height: 0))
}
}
fileprivate struct NavigationBarLargeTitleItems<L : View>: UIViewControllerRepresentable {
typealias UIViewControllerType = Wrapper
private let trailingItems: L
init(trailing: L) {
self.trailingItems = trailing
}
func makeUIViewController(context: Context) -> Wrapper {
Wrapper(representable: self)
}
func updateUIViewController(_ uiViewController: Wrapper, context: Context) {
}
class Wrapper: UIViewController {
private let representable: NavigationBarLargeTitleItems?
init(representable: NavigationBarLargeTitleItems) {
self.representable = representable
super.init(nibName: nil, bundle: nil)
}
required init?(coder: NSCoder) {
self.representable = nil
super.init(coder: coder)
}
override func viewWillAppear(_ animated: Bool) {
guard let representable = self.representable else { return }
guard let navigationBar = self.navigationController?.navigationBar else { return }
guard let UINavigationBarLargeTitleView = NSClassFromString("_UINavigationBarLargeTitleView") else { return }
navigationBar.subviews.forEach { subview in
if subview.isKind(of: UINavigationBarLargeTitleView.self) {
let controller = UIHostingController(rootView: representable.trailingItems)
controller.view.translatesAutoresizingMaskIntoConstraints = false
subview.addSubview(controller.view)
NSLayoutConstraint.activate([
controller.view.bottomAnchor.constraint(
equalTo: subview.bottomAnchor,
constant: -15
),
controller.view.trailingAnchor.constraint(
equalTo: subview.trailingAnchor,
constant: -view.directionalLayoutMargins.trailing
)
])
}
}
}
}
}
用法：
import SwiftUI
import NavigationBarLargeTitleItems
struct ContentView: View {
var body: some View {
NavigationView {
List {
ForEach(1..<50) { index in
Text("Sample Row \(String(index))")
}
}
.navigationTitle("Navigation")
.navigationBarLargeTitleItems(trailing: ProfileIcon())
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
struct ProfileIcon: View {
var body: some View{
Button(action: {
print("Profile button was tapped")
}) {
Image(systemName: "person.circle.fill")
.resizable()
.aspectRatio(contentMode: .fit)
.foregroundColor(.red)
.frame(width: 36, height: 36)
}
.offset(x: -20, y: 5)
}
}
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