我正在為 iOS 和 Mac Catalyst 構建一個應用程式，并且已經能夠撰寫我想要的大部分體驗，除了在 iOS 中使用滑動洗掉的功能。
該視圖包括多個部分，每個部分都有一個 List 和 ForEach 閉包。我希望能夠將 EditButton() 函式添加到每個部分的標題中，并讓它僅應用于該部分的串列。
我可以添加一個 EditButton() 函式來獲得此功能，但是，到目前為止，我只能使它適用于整個螢屏，而不適用于各個部分。
我嘗試將每個部分的代碼重構為函式和結構（如下所示）。在所有情況下，EditButton() 都會激活所有串列行的洗掉圖示，而不僅僅是帶有按鈕的部分。
我還嘗試將 EditButton() 放在 VStack 的部分內。沒有不同。
這是一個帶有最新代碼嘗試的簡單示例：
struct ContentView: View {
@State private var selectedItem: String?
@State private var items = ["One", "Two", "Three", "Four", "Five"]
@State private var fruits = ["Apple", "Orange", "Pear", "Lemon", "Grape"]
var body: some View {
NavigationSplitView {
ItemSection(selectedItem: $selectedItem, items: $items)
FruitSection(selectedItem: $selectedItem, fruits: $fruits)
} detail: {
if let selectedItem {
ItemDetailView(selectedItem: selectedItem)
} else {
EmptyView()
}
}//nav
}//body
}//struct
struct ItemSection: View {
@Binding var selectedItem: String?
@Binding var items: [String]
var body: some View {
Section {
VStack {
List(selection: $selectedItem) {
ForEach(items, id: \.self) { item in
NavigationLink(value: item) {
Text(item)
}
}
.onDelete { items.remove(atOffsets: $0) }
}
.listStyle(PlainListStyle())
}//v
.padding()
} header: {
HStack {
Text("Section for Items")
Spacer()
//uncomment when you have it working
//#if targetEnvironment(macCatalyst)
EditButton()
//#endif
}//h
.padding(.horizontal, 10)
}//section and header
}//body
}//item section
struct FruitSection: View {
@Binding var selectedItem: String?
@Binding var fruits: [String]
var body: some View {
Section {
VStack {
List(selection: $selectedItem) {
ForEach(fruits, id: \.self) { fruit in
NavigationLink(value: fruit) {
Text(fruit)
}
}
.onDelete { fruits.remove(atOffsets: $0) }
}
.listStyle(PlainListStyle())
}//v
.padding()
} header: {
HStack {
Text("Section for Fruits")
Spacer()
}//h
.padding(.horizontal, 10)
}//section fruit
}//body
}//fruit section
struct ItemDetailView: View {
var selectedItem: String
var body: some View {
VStack {
Text(selectedItem)
Text("This is the DetailView")
}
}
}
任何指導將不勝感激。Xcode 14.0.1 iOS 16
uj5u.com熱心網友回復：
import SwiftUI
struct ContentView: View {
@State private var selectedItem: String?
@State private var items = ["One", "Two", "Three", "Four", "Five"]
@State private var fruits = ["Apple", "Orange", "Pear", "Lemon", "Grape"]
var body: some View {
NavigationSplitView {
ItemSection(selectedItem: $selectedItem, items: $items)
FruitSection(selectedItem: $selectedItem, fruits: $fruits)
} detail: {
if let selectedItem {
ItemDetailView(selectedItem: selectedItem)
} else {
EmptyView()
}
}//nav
}//body
}//struct
struct ItemSection: View {
@Binding var selectedItem: String?
@Binding var items: [String]
@State var isEditMode = false // this is what you need
var body: some View {
Section {
VStack {
List(selection: $selectedItem) {
ForEach(items, id: \.self) { item in
NavigationLink(value: item) {
Text(item)
}
}
.onDelete { items.remove(atOffsets: $0) }
}
.environment(\.editMode, isEditMode ? .constant(.active) : .constant(.inactive)) // and set this
.listStyle(PlainListStyle())
}//v
.padding()
} header: {
HStack {
Text("Section for Items")
Spacer()
//uncomment when you have it working
//#if targetEnvironment(macCatalyst)
Button { // you also need to set EditButton() -> Button()
withAnimation {
isEditMode.toggle()
}
} label: {
Text(isEditMode ? "Done" : "Edit")
}
//#endif
}//h
.padding(.horizontal, 10)
}//section and header
}//body
}//item section
struct FruitSection: View {
@Binding var selectedItem: String?
@Binding var fruits: [String]
@State var isEditMode = false // same as this section
var body: some View {
Section {
VStack {
List(selection: $selectedItem) {
ForEach(fruits, id: \.self) { fruit in
NavigationLink(value: fruit) {
Text(fruit)
}
}
.onDelete { fruits.remove(atOffsets: $0) }
}
.environment(\.editMode, isEditMode ? .constant(.active) : .constant(.inactive))
.listStyle(PlainListStyle())
}//v
.padding()
} header: {
HStack {
Text("Section for Fruits")
Spacer()
Button {
withAnimation {
isEditMode.toggle()
}
} label: {
Text(isEditMode ? "Done" : "Edit")
}
}//h
.padding(.horizontal, 10)
}//section fruit
}//body
}//fruit section
struct ItemDetailView: View {
var selectedItem: String
var body: some View {
VStack {
Text(selectedItem)
Text("This is the DetailView")
}
}
}
uj5u.com熱心網友回復：
這是一個更通用和簡化的方法，使用PreferenceKey：
struct EditModeViewModifier: ViewModifier {
var forceEditing: Bool?
@State var isEditing = false
func body(content: Content) -> some View {
content
.onPreferenceChange(IsEditingPrefrenceKey.self) { newValue in
withAnimation {
isEditing = newValue
}
}.environment(\.editMode, .constant((forceEditing ?? isEditing) ? .active: .inactive))
}
}
extension View {
func editMode(_ editing: Bool? = nil) -> some View {
modifier(EditModeViewModifier(forceEditing: editing))
}
}
struct EditingButton: View {
@State var isEditing = false
var body: some View {
Button(action: {
isEditing.toggle()
}) {
Text(isEditing ? "Done" : "Edit")
}.preference(key: IsEditingPrefrenceKey.self, value: isEditing)
}
}
struct IsEditingPrefrenceKey: PreferenceKey {
static var defaultValue = false
static func reduce(value: inout Bool, nextValue: () -> Bool) {
value = nextValue()
}
}
您使用EditingButton而不是EditButton, &.editMode()在您的View. 然后你的部分變成這樣：
struct ItemSection: View {
@Binding var selectedItem: String?
@Binding var items: [String]
var body: some View {
Section {
VStack {
List(selection: $selectedItem) {
ForEach(items, id: \.self) { item in
NavigationLink(value: item) {
Text(item)
}
}.onDelete { items.remove(atOffsets: $0) }
}.listStyle(PlainListStyle())
}.padding()
} header: {
HStack {
Text("Section for Items")
Spacer()
//uncomment when you have it working
//#if targetEnvironment(macCatalyst)
EditingButton()
//#endif
}.padding(.horizontal, 10)
}.editMode()
}
}
struct FruitSection: View {
@Binding var selectedItem: String?
@Binding var fruits: [String]
var body: some View {
Section {
VStack {
List(selection: $selectedItem) {
ForEach(fruits, id: \.self) { fruit in
NavigationLink(value: fruit) {
Text(fruit)
}
}.onDelete { fruits.remove(atOffsets: $0) }
}.listStyle(PlainListStyle())
}.padding()
} header: {
HStack {
Text("Section for Fruits")
Spacer()
EditingButton()
}.padding(.horizontal, 10)
}.editMode()
}
}
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標籤：ios代码迅捷
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