我在 VStack 中有一个 Picker 元素,但是当通过添加新元素更改其内容时,Picker 不会刷新。
隐藏和显示选取器后,新元素可见。
有谁知道如何刷新选择器的内容,而不需要隐藏/显示它?
您可以通过创建一个新的 SwiftUI 项目并复制以下代码而不是“ContentView”结构来重现此内容。
class ContentModel {
@Published var pickerData: [String] = ["1"]
func addPickerData() {
pickerData.append("\(pickerData.count + 1)")
}
}
struct ContentView: View {
let contentModel = ContentModel()
@State private var showPicker = false
@State private var selectedPickerValue = ""
var body: some View {
VStack(spacing: 8) {
Text("Adding a new Element to the Picker does not refresh its content :-(")
Button(action: {
self.contentModel.addPickerData()
}) {
Text("Add Picker Data")
}
Button(action: {
self.showPicker.toggle()
}) {
Text("Show / Hide 2nd Picker")
}
Picker("Select",selection: $selectedPickerValue) {
ForEach(contentModel.pickerData, id: \.self) { data in
Text(data)
}
}
if (showPicker) {
Picker("Select",selection: $selectedPickerValue) {
ForEach(contentModel.pickerData, id: \.self) { data in
Text(data)
}
}
}
Text("Selected Value: \(selectedPickerValue)")
}
}
}
预先感谢您的任何帮助!
这是反应式的技巧,当你需要刷新某些东西时,总是使用同一东西的两个副本。
class ContentModel{
@Published var pickerData: [String] = ["1"]
func addPickerData() {
pickerData.append("\(pickerData.count + 1)")
}
}
struct ContentSSView: View {
let contentModel = ContentModel()
@State private var showPicker = false
@State private var selectedPickerValue = ""
var body: some View {
VStack(spacing: 8) {
Text("Adding a new Element to the Picker does not refresh its content :-(")
Button(action: {
self.contentModel.addPickerData()
self.showPicker.toggle()
}) {
Text("Add Picker Data")
}
Button(action: {
self.showPicker.toggle()
}) {
Text("Show / Hide 2nd Picker")
}
if (showPicker) {
Picker("Select",selection: $selectedPickerValue) {
ForEach(contentModel.pickerData, id: \.self) { data in
Text(data)
}
}
}else{
Picker("Select",selection: $selectedPickerValue) {
ForEach(contentModel.pickerData, id: \.self) { data in
Text(data)
}
}
}
Text("Selected Value: \(selectedPickerValue)")
}
}
}
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