基于@Published数组的SwiftUI文本字段未更新

Question

我正在尝试布置一组CustomTextView，它们可以在SwiftUITextField或Text视图之间切换。

考虑这个例子。

import SwiftUI
struct ContentView: View {

@StateObject var doc: Document = Document()

var body: some View {

ForEach(doc.lines, id: .self) { line in
HStack {
ForEach(line, id: .self) { word in
CustomTextView(text: word, document: doc)
.fixedSize()
}
Spacer()
}
}
.frame(width: 300, height: 300)
.background(.cyan)
}
}
struct CustomTextView: View {
@State var text: String
@State var isEditing: Bool = false
@ObservedObject var document: Document

var body: some View {
if isEditing {
TextField("", text: $text)
.onSubmit {
isEditing.toggle()

// NOTE: reset document anytime a word ends in "?"
if text.last! == "?" {
print("resetting")
document.lines = [["Reset"]]
print(document.lines)
}
}
} else {
Text(text)
.onTapGesture {
isEditing.toggle()
}
}
}
}

class Document: ObservableObject {
@Published var lines: [[String]] = [["Hello"]]
}

我想要的是，我应该能够无限期地重置文本。但是，视图只会正确重置一次(请参见gif(。所有重置document.lines的进一步更新都是不正确的，即使打印语句显示@Published属性lines正在明显更改。

我做错了什么？

Answer 1

您需要使用document.lines[index]更新文本字段文本，其中index是document.lines数组中行的索引。所以你需要更新如下。

struct CustomTextView: View {
@State var isEditing: Bool = false
@ObservedObject var document: Document
var body: some View {
if isEditing {
TextField("", text: $document.lines[index])
.onSubmit {
isEditing.toggle()

// NOTE: reset document anytime a word ends in "?"
if document.lines[index].last! == "?" {
print("resetting")
document.lines = [["Reset"]]
print(document.lines)
}
}
} else {
Text(text)
.onTapGesture {
isEditing.toggle()
}
}
}
}