CircleImage 在选择器中选择一个选项并添加到列表后不断改变颜色
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【中文标题】CircleImage 在选择器中选择一个选项并添加到列表后不断改变颜色【英文标题】：CircleImage keeps changing colour after selecting an option in picker and adding to list 【发布时间】：2020-08-09 20:26:42 【问题描述】：我遇到了一个奇怪的问题，当添加具有不同颜色的新项目时，列表中项目的颜色会发生变化，本质上它不会保留其颜色值，而是采用新的颜色值。 我要做的是显示与用户选择的优先级相对应的颜色。
代码如下：
struct PriorityGreen: View
var body: some View
Circle()
.frame(width: 20, height: 20)
.foregroundColor(Color.green)
struct PriorityYellow: View
var body: some View
Circle()
.frame(width: 20, height: 20)
.foregroundColor(Color.yellow)
struct PriorityOrange: View
var body: some View
Circle()
.frame(width: 20, height: 20)
.foregroundColor(Color.orange)
struct PriorityRed: View
var body: some View
Circle()
.frame(width: 20, height: 20)
.foregroundColor(Color.red)
查看代码
import SwiftUI
struct AppView: View
@ObservedObject var data = Model()
@State var showViewTwo = false
var body: some View
NavigationView
VStack
List
ForEach(data.arrayOfTask, id: \.self) row in
HStack
if self.data.priority == 0
PriorityGreen()
else if self.data.priority == 1
PriorityYellow()
else if self.data.priority == 2
PriorityOrange()
else if self.data.priority == 3
PriorityRed()
Text("\(row)")
.onDelete(perform: removeItems).animation(.default)
.listStyle(GroupedListStyle())
.environment(\.horizontalSizeClass, .regular)
.navigationBarTitle("Tasks")
.navigationBarItems(leading:
EditButton().animation(.default),
trailing: Button(action:
self.showViewTwo.toggle()
)
Text("New task")
.sheet(isPresented: $showViewTwo)
ViewTwo(data: self.data, showViewTwo: self.$showViewTwo)
)
func removeItems(at offset: IndexSet)
data.arrayOfTask.remove(atOffsets: offset)
struct AppView_Previews: PreviewProvider
static var previews: some View
AppView()
struct ViewTwo: View
@State var data: Model
@State var newName = ""
@State var newCatergory = ""
@State var newPriorityLevel = ""
@State var defaultPriorityLevel = 1
@State var priorityTypes = ["low", "medium", "high", "critical"]
@Binding var showViewTwo: Bool
var body: some View
NavigationView
Form
Section(header: Text("Add task name"))
TextField("Name", text: $newName)
/*
This section will be implementated later on
TextField("Catergory", text: $newCatergory)
*/
Section(header: Text("Select task priority"))
Picker("Priority Levels", selection: $defaultPriorityLevel)
ForEach(0..<priorityTypes.count)
Text(self.priorityTypes[$0])
.pickerStyle(SegmentedPickerStyle())
.navigationBarTitle("New task details")
.navigationBarItems(trailing:
Button("Save")
self.showViewTwo.toggle()
self.data.taskName = self.newName
self.data.arrayOfTask.append(self.newName)
self.data.priority = self.defaultPriorityLevel
)
struct PriorityCirleView: View
var body: some View
Circle()
.frame(width: 20, height: 20)
.foregroundColor(Color.green)
import SwiftUI
enum Catergory
case work
case home
case family
case health
case bills
enum Priority
case low
case medium
case high
case critical
class Model: ObservableObject
@Published var taskName = ""
@Published var taskCategory = ""
@Published var priority = 0
@Published var arrayOfTask = [String]()
这个 gif 更清楚地展示了这个问题
(Gif)[https://imgur.com/a/ffzpSft]
【问题讨论】：
在帖子中添加了模型 【参考方案1】：您的模型中只有一个优先级，而不是每个任务的优先级。
将您的模型更改为：
class Model: ObservableObject
struct Task
var taskName = ""
var taskCategory = ""
var priority = 0
@Published var arrayOfTask = [Task]()
并更新您的代码以使用新模型：
struct AppView: View
@ObservedObject var data = Model()
@State var showViewTwo = false
var body: some View
NavigationView
VStack
List
ForEach(data.arrayOfTask, id: \.taskName) task in
HStack
if task.priority == 0
PriorityGreen()
else if task.priority == 1
PriorityYellow()
else if task.priority == 2
PriorityOrange()
else if task.priority == 3
PriorityRed()
Text("\(task.taskName)")
.onDelete(perform: removeItems).animation(.default)
.listStyle(GroupedListStyle())
.environment(\.horizontalSizeClass, .regular)
.navigationBarTitle("Tasks")
.navigationBarItems(leading:
EditButton().animation(.default),
trailing: Button(action:
self.showViewTwo.toggle()
)
Text("New task")
.sheet(isPresented: $showViewTwo)
ViewTwo(data: self.data, showViewTwo: self.$showViewTwo)
)
func removeItems(at offset: IndexSet)
data.arrayOfTask.remove(atOffsets: offset)
struct ViewTwo: View
@State var data: Model
@State var newName = ""
@State var newCatergory = ""
@State var newPriorityLevel = ""
@State var defaultPriorityLevel = 1
@State var priorityTypes = ["low", "medium", "high", "critical"]
@Binding var showViewTwo: Bool
var body: some View
NavigationView
Form
Section(header: Text("Add task name"))
TextField("Name", text: $newName)
/*
This section will be implementated later on
TextField("Catergory", text: $newCatergory)
*/
Section(header: Text("Select task priority"))
Picker("Priority Levels", selection: $defaultPriorityLevel)
ForEach(0..<priorityTypes.count)
Text(self.priorityTypes[$0])
.pickerStyle(SegmentedPickerStyle())
.navigationBarTitle("New task details")
.navigationBarItems(trailing:
Button("Save")
var task = Model.Task()
self.showViewTwo.toggle()
task.taskName = self.newName
task.priority = self.defaultPriorityLevel
self.data.arrayOfTask.append(task)
)
使用taskName 作为id 不是一个好主意。更新您的 Task 结构以包含唯一值：
class Model: ObservableObject
struct Task: Identifiable
static var uniqueID = 0
var taskName = ""
var taskCategory = ""
var priority = 0
var id = 0
init()
Task.uniqueID += 1
self.id = Task.uniqueID
@Published var arrayOfTask = [Task]()
然后改变：
ForEach(data.arrayOfTask, id: \.taskName) task in
到
ForEach(data.arrayOfTask) task in
【讨论】：
感谢您的回复，代码现在按预期工作，我会在早上第一件事尝试更好地理解它。再次感谢您。 检查我的更新。该代码使用taskName 作为id，这意味着具有相同名称的2 个任务将显示相同的优先级。我创建了Task Identifiable 并为其添加了一个独特的id 值。以上是关于CircleImage 在选择器中选择一个选项并添加到列表后不断改变颜色的主要内容，如果未能解决你的问题，请参考以下文章