SwiftUI:支持多通道
SwiftUI:支持多通道
提问于 2019-07-19 07:29:59
我正在尝试设置一个视图，它可以根据点击的按钮显示多个模态。
当我只添加一个sheet时，一切都正常：
.sheet(isPresented: $showingModal1) { ... }但是当我添加另一个工作表时，只有最后一个工作表有效。
.sheet(isPresented: $showingModal1) { ... }
.sheet(isPresented: $showingModal2) { ... }更新
我试图让它正常工作，但我不确定如何为modal声明类型。我收到一个Protocol 'View' can only be used as a generic constraint because it has Self or associated type requirements的错误。
struct ContentView: View {
@State var modal: View?
var body: some View {
VStack {
Button(action: {
self.modal = ModalContentView1()
}) {
Text("Show Modal 1")
}
Button(action: {
self.modal = ModalContentView2()
}) {
Text("Show Modal 2")
}
}.sheet(item: self.$modal, content: { modal in
return modal
})
}
}
struct ModalContentView1: View {
var body: some View {
Text("Modal 1")
}
}
struct ModalContentView2: View {
var body: some View {
Text("Modal 2")
}
}回答 8
Stack Overflow用户
发布于 2019-09-10 22:37:06
这是可行的：
.background(EmptyView().sheet(isPresented: $showingModal1) { ... }
.background(EmptyView().sheet(isPresented: $showingModal2) { ... }))请注意这些是如何嵌套的backgrounds。不是一个接一个的两个背景。
感谢DevAndArtist找到了这一点。
Stack Overflow用户
发布于 2019-07-19 13:04:44
也许我没有抓住要点，但您可以通过对.sheet()的一次调用或多次调用来实现。
Multiple .sheet() approach:
import SwiftUI
struct MultipleSheets: View {
@State private var sheet1 = false
@State private var sheet2 = false
@State private var sheet3 = false
var body: some View {
VStack {
Button(action: {
self.sheet1 = true
}, label: { Text("Show Modal #1") })
.sheet(isPresented: $sheet1, content: { Sheet1() })
Button(action: {
self.sheet2 = true
}, label: { Text("Show Modal #2") })
.sheet(isPresented: $sheet2, content: { Sheet2() })
Button(action: {
self.sheet3 = true
}, label: { Text("Show Modal #3") })
.sheet(isPresented: $sheet3, content: { Sheet3() })
}
}
}
struct Sheet1: View {
var body: some View {
Text("This is Sheet #1")
}
}
struct Sheet2: View {
var body: some View {
Text("This is Sheet #2")
}
}
struct Sheet3: View {
var body: some View {
Text("This is Sheet #3")
}
}Single .sheet()方法：
struct MultipleSheets: View {
@State private var showModal = false
@State private var modalSelection = 1
var body: some View {
VStack {
Button(action: {
self.modalSelection = 1
self.showModal = true
}, label: { Text("Show Modal #1") })
Button(action: {
self.modalSelection = 2
self.showModal = true
}, label: { Text("Show Modal #2") })
Button(action: {
self.modalSelection = 3
self.showModal = true
}, label: { Text("Show Modal #3") })
}
.sheet(isPresented: $showModal, content: {
if self.modalSelection == 1 {
Sheet1()
}
if self.modalSelection == 2 {
Sheet2()
}
if self.modalSelection == 3 {
Sheet3()
}
})
}
}
struct Sheet1: View {
var body: some View {
Text("This is Sheet #1")
}
}
struct Sheet2: View {
var body: some View {
Text("This is Sheet #2")
}
}
struct Sheet3: View {
var body: some View {
Text("This is Sheet #3")
}
}Stack Overflow用户
发布于 2020-02-18 16:32:17
我不确定这是否总是可能的，但是在Xcode11.3.1中，对于这种用例(https://developer.apple.com/documentation/swiftui/view/3352792-sheet)，有一个重载的.sheet()。您可以使用可识别的项而不是布尔值来调用它：
struct ModalA: View {
var body: some View {
Text("Hello, World! (A)")
}
}
struct ModalB: View {
var body: some View {
Text("Hello, World! (B)")
}
}
struct MyContentView: View {
enum Sheet: Hashable, Identifiable {
case a
case b
var id: Int {
return self.hashValue
}
}
@State var activeSheet: Sheet? = nil
var body: some View {
VStack(spacing: 42) {
Button(action: {
self.activeSheet = .a
}) {
Text("Hello, World! (A)")
}
Button(action: {
self.activeSheet = .b
}) {
Text("Hello, World! (B)")
}
}
.sheet(item: $activeSheet) { item in
if item == .a {
ModalA()
} else if item == .b {
ModalB()
}
}
}
}页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/57103800
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