swipeActions 是 SwiftUI 中用于为列表项添加滑动操作的修饰符。让我通过示例来详细解释：
1. 基本用法 #
List {
ForEach(items) { item in
Text(item.title)
.swipeActions {
Button("删除") {
// 删除操作
}
}
}
}
2. 完整示例 #
struct ContentView: View {
@State private var items = ["项目1", "项目2", "项目3"]
var body: some View {
List {
ForEach(items, id: \.self) { item in
Text(item)
.swipeActions(edge: .trailing, allowsFullSwipe: true) {
Button(role: .destructive) {
delete(item)
} label: {
Label("删除", systemImage: "trash")
}
Button {
share(item)
} label: {
Label("分享", systemImage: "square.and.arrow.up")
}
.tint(.blue)
}
.swipeActions(edge: .leading) {
Button {
favorite(item)
} label: {
Label("收藏", systemImage: "star")
}
.tint(.yellow)
}
}
}
}
func delete(_ item: String) {
if let index = items.firstIndex(of: item) {
items.remove(at: index)
}
}
func share(_ item: String) {
// 分享操作
}
func favorite(_ item: String) {
// 收藏操作
}
}
3. 实际应用示例 #
邮件列表 #
struct EmailListView: View {
@State private var emails: [Email] = []
var body: some View {
List {
ForEach(emails) { email in
EmailRow(email: email)
.swipeActions(edge: .trailing, allowsFullSwipe: true) {
Button(role: .destructive) {
deleteEmail(email)
} label: {
Label("删除", systemImage: "trash")
}
Button {
archiveEmail(email)
} label: {
Label("归档", systemImage: "archivebox")
}
.tint(.blue)
}
.swipeActions(edge: .leading) {
Button {
markAsUnread(email)
} label: {
Label("未读", systemImage: "envelope.badge")
}
.tint(.gray)
Button {
flagEmail(email)
} label: {
Label("标记", systemImage: "flag")
}
.tint(.orange)
}
}
}
}
}
Todo 列表 #
struct TodoListView: View {
@State private var todos: [Todo] = []
var body: some View {
List {
ForEach(todos) { todo in
TodoRow(todo: todo)
.swipeActions(edge: .trailing) {
Button(role: .destructive) {
deleteTodo(todo)
} label: {
Label("删除", systemImage: "trash")
}
}
.swipeActions(edge: .leading) {
Button {
toggleComplete(todo)
} label: {
Label(
todo.isCompleted ? "取消完成" : "完成",
systemImage: todo.isCompleted ? "xmark.circle" : "checkmark.circle"
)
}
.tint(todo.isCompleted ? .gray : .green)
Button {
togglePriority(todo)
} label: {
Label("优先", systemImage: "star")
}
.tint(.yellow)
}
}
}
}
}
聊天列表 #
struct ChatListView: View {
@State private var chats: [Chat] = []
var body: some View {
List {
ForEach(chats) { chat in
ChatRow(chat: chat)
.swipeActions(edge: .trailing, allowsFullSwipe: false) {
Button(role: .destructive) {
deleteChat(chat)
} label: {
Label("删除", systemImage: "trash")
}
Button {
muteChat(chat)
} label: {
Label(
chat.isMuted ? "取消静音" : "静音",
systemImage: chat.isMuted ? "speaker.wave.2" : "speaker.slash"
)
}
.tint(.gray)
}
.swipeActions(edge: .leading) {
Button {
pinChat(chat)
} label: {
Label(
chat.isPinned ? "取消置顶" : "置顶",
systemImage: "pin"
)
}
.tint(.blue)
}
}
}
}
}
4. 自定义样式 #
struct CustomSwipeView: View {
var body: some View {
List {
ForEach(items) { item in
Text(item.title)
.swipeActions {
// 自定义按钮样式
Button {
// 操作
} label: {
Label("自定义", systemImage: "star")
.font(.headline)
.padding()
}
.tint(.purple)
}
}
}
}
}
5. SwipeActions 文档 #
/// A modifier that configures the swipe actions for a list row.
///
/// Use this modifier to add swipe actions to a list row. The actions appear when
/// the user swipes horizontally across the row.
///
/// - Parameters:
/// - edge: The edge from which the actions appear. Defaults to `.trailing`.
/// - allowsFullSwipe: A Boolean value that determines whether swiping past
/// a threshold automatically triggers the first action. Defaults to `true`.
/// - content: The actions to display when swiping.
@available(iOS 15.0, macOS 12.0, *)
@available(tvOS, unavailable)
@available(watchOS, unavailable)
extension View {
public func swipeActions<Content>(
edge: HorizontalEdge = .trailing,
allowsFullSwipe: Bool = true,
@ViewBuilder content: () -> Content
) -> some View where Content : View
}
参数说明： #
edge
.trailing: 从右向左滑动（默认）.leading: 从左向右滑动
allowsFullSwipe
true: 允许完整滑动触发第一个操作（默认）false: 禁用完整滑动触发
content
- 使用 ViewBuilder 构建的滑动操作内容
- 通常包含一个或多个 Button 视图
注意事项： #
平台支持
- iOS 15.0+
- macOS 12.0+
- 不支持 tvOS 和 watchOS
性能考虑
- 避免在滑动操作中包含复杂的视图层级
- 保持操作简单直接
用户体验
- 最常用的操作应放在最外侧
- 危险操作应使用
role: .destructive - 考虑是否需要允许完整滑动触发
可访问性
- 为操作提供清晰的标签
- 考虑使用适当的图标
状态管理
- 确保操作能正确更新视图状态
- 处理可能的错误情况