[英]SwiftUI how to update a view when the object in a published array is updated and not the array itself
[英]How can I toggle a property of an object in an array and update the SwiftUI view?
SwiftUI 问题。 我的这段代码给了我错误“编译器无法在合理的时间内对该表达式进行类型检查; 尝试将表达式分解为不同的子表达式”。 错误是因为 feel.selected.toggle()。 myFeelings 是一个 ObservableObject Class,它包含一个结构体的感觉数组。 我希望能够在按下按钮并更新视图时将选定的属性更改为 true 或 false。 我不知道是否有人可以帮助我,我一般都是编码新手。
ForEach(myFeelings.feelings.indices) { index in
ZStack {
Button(action: {
self.myFeelings.feelings[index].selected.toggle()
print("A")
}) {
Text(self.myFeelings.feelings[index].emoji)
.font(.system(size: 40))
}
Text(String(self.myFeelings.feelings[index].selected))
.font(.system(size: 10))
}
}
这是我想用选定的感受更新的部分。
ForEach(myFeelings.feelings.indices) { index in
Group {
if self.myFeelings.feelings[index].selected {
ZStack {
Rectangle()
.frame(height: 100)
.foregroundColor(self.myFeelings.feelings[index].color)
.scaledToFill()
}
}
}
}
这是数组:
@State var myFeelings = Feelings(feelings:[Feeling(feeling: "Joy", emoji: "😂", color: Color(#colorLiteral(red: 0.9607843137254902, green: 0.7058823529411765, blue: 0.2, alpha: 1.0))),
Feeling(feeling: "Trust", emoji: "😌", color: Color(#colorLiteral(red: 0.4666666666666667, green: 0.7647058823529411, blue: 0.26666666666666666, alpha: 1.0))),
Feeling(feeling: "Fear", emoji: "😰", color: Color(#colorLiteral(red: 0.27450980392156865, green: 0.48627450980392156, blue: 0.1411764705882353, alpha: 1.0))),
Feeling(feeling: "Surprise", emoji: "😮", color: Color(#colorLiteral(red: 0.12941176470588237, green: 0.21568627450980393, blue: 0.06666666666666667, alpha: 1.0))),
Feeling(feeling: "Sadness", emoji: "😢", color: Color(#colorLiteral(red: 0.17647058823529413, green: 0.4980392156862745, blue: 0.7568627450980392, alpha: 1.0))),
Feeling(feeling: "Disgust", emoji: "🤮", color: Color(#colorLiteral(red: 0.12156862745098039, green: 0.011764705882352941, blue: 0.4235294117647059, alpha: 1.0))),
Feeling(feeling: "Anger", emoji: "😡", color: Color(#colorLiteral(red: 0.7450980392156863, green: 0.1568627450980392, blue: 0.07450980392156863, alpha: 1.0))),
Feeling(feeling: "Anticipation", emoji: "😏", color: Color(#colorLiteral(red: 0.9372549019607843, green: 0.34901960784313724, blue: 0.19215686274509805, alpha: 1.0)))])
感觉和感觉是结构
在你的 foreach 中使用索引,并用 @State 声明 myFeelings,这是一个完整的工作示例:
struct FeelingGroup {
var feelings: [Feeling]
}
struct Feeling {
var selected: Bool
var emoji: String
}
struct ToggleView: View {
@State var myFeelings = FeelingGroup(feelings: [Feeling(selected: true, emoji: "A"),
Feeling(selected: true, emoji: "B"),
Feeling(selected: false, emoji: "C")])
var body: some View {
VStack{
ForEach(myFeelings.feelings.indices) { index in
HStack {
Button(action: {
self.myFeelings.feelings[index].selected.toggle()
print("A")
}) {
Text(self.myFeelings.feelings[index].emoji)
.font(.system(size: 40))
}
Text(String(self.myFeelings.feelings[index].selected))
.font(.system(size: 40))
}
}
}
}
}
struct ToggleView_Previews: PreviewProvider {
static var previews: some View {
ToggleView()
}
}
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