SwiftUI

Question

我目前正在处理#hackingwithswift 的项目 4。我遇到无法从表单视图中更改选择器样式的问题。

这是我正在处理的一小段代码。请假设其余代码是正确的。无论我在 .pickerStyle() 中输入什么修饰符，我总是得到错误：

Type 'WheelPickerStyle.Type' cannot conform to 'PickerStyle'; only struct/enum/class types can conform to protocols

NavigationView{
        Form{
            Section(header: Text("When do you want to wake up?") .font(.headline)) {
                
                DatePicker("Please enter a time", selection: $wakeUp, displayedComponents: .hourAndMinute)
                    .datePickerStyle(WheelDatePickerStyle())
                    .labelsHidden()
            }
            
            Section(header: Text("Desired amount of sleep")
                .font(.headline)) {
                
                Stepper(value: $sleepAmount, in: 4...12, step: 0.25) {
                    Text("\(sleepAmount, specifier: "%g") hours")
                }
            }
            
            Section(header: Text("Daily coffee intake")
                .font(.headline)) {
                    
                    Picker("Number of coffees had in a day", selection: $coffeeAmount) {
                            Text("1")
                            Text("2")
                            Text("3")
                        }
                    .pickerStyle(WheelPickerStyle)
                    }

谁能帮帮我？请解释我做错了什么，我是初学者！

提前致谢！

Answer 1

在你的代码中

Picker("Number of coffees had in a day", selection: $coffeeAmount) {
                            Text("1")
                            Text("2")
                            Text("3")
                        }
                    .pickerStyle(WheelPickerStyle)
                    }

您应该使用 WheelPickerStyle() 而不是 WheelPickerStyle

SwiftUI - 无法在表单中向选择器视图添加修饰符

SwiftUI - Can't add modifiers to Picker View within a form

picker

pickerview