Ios 在 SwiftUI 中将 TextEditor 文本计数连接到 ProgressView

我正在创建一个日志(log)应用程序，它会鼓励用户在早报部分至少写100个字符.我想通过在TextEditor的底部放置一个ProgressView来实现这一点.然后，根据用户的输入，进度条将从0%变为100%，如果他们写的字符超过100个，则保持在100%.进度条指示创建条目所需的最小字符数.

import SwiftUI
import Combine

struct AddNewEntryView: View {

@Environment(\.dismiss) var dismiss
@EnvironmentObject var data : JournalEntriesData
@State var typeOfNewEntry : EntryType
@State var newEntry : Entry
@State var progressValue: Double = 0.0
let MIN_ENTRY_CHARS = 10

let detector = PassthroughSubject<Void, Never>()
let publisher: AnyPublisher<Void, Never>

init(entryType: EntryType) {
    _typeOfNewEntry = State(initialValue: entryType)
    _newEntry = State(initialValue: Entry(type: entryType, text: ""))
    
    publisher = detector
        .debounce(for: .seconds(1), scheduler: DispatchQueue.main)
        .eraseToAnyPublisher()
}

func limitTo(num: Double, maxNum: Double) -> Double {
    return num > maxNum ? maxNum : num
}

private func updateProgressBar() {
    print("char count", newEntry.text.count)
    progressValue = Double(newEntry.text.count / MIN_ENTRY_CHARS)
}

var body: some View {
    VStack {
        Form {
            Text(newEntry.created, style: .date)
                .font(.headline)
            Section("Entry") {
                TextEditor(text: $newEntry.text)
                    .foregroundColor(.secondary)
                    .padding(.horizontal)
                    .frame(minHeight: 80)
                    .onChange(of: newEntry.text) { _ in detector.send() }
                    .onReceive(publisher) {  updateProgressBar() 
                    }
                }
            ProgressView("Character count", value: $progressValue, total: 1.0)
        }
    }
    .toolbar {
        ToolbarItem {
            Button("Add") {
                data.entries.append(newEntry)
                dismiss()
            }
        }
      }
  }
}

struct AddNewEntryView_Previews: PreviewProvider {
    static var previews: some View {
        AddNewEntryView(entryType: .MORNING_PAGES)
    }
}

我现在几乎就知道了，但我的ProgressView告诉我，它无法将类型Double的值转换为预期的参数类型绑定，但我已经在那里使用了美元符号.它还在第二个错误中指出，初始值设定项(在它的value total中)要求绑定符合"BinaryFloatingPoint".我刚接触Swift ，在这里打字时有点迷路.