如下面代码所示，希望用Picker画一个时间选择器。

struct DatePickerView: View {
    @State var dateHour: Int = 0
    @State var dateMinute: Int = 0
    var body: some View {
        VStack {

            HStack {

                HStack {
                    Picker("Hour", selection: $dateHour) {
                        ForEach(0..<24) { i in
                            Text(CommonUtil.appendZero(num: i)).frame(width: 30)
                        }
                    }.frame(width: 50).pickerStyle(WheelPickerStyle())
                }

                Text(":")

                HStack {
                    Picker("Minute", selection: $dateMinute) {
                        ForEach(0..<60) { i in
                            Text(CommonUtil.appendZero(num: i)).frame(width: 30)
                        }
                    }.frame(width: 50).pickerStyle(WheelPickerStyle())
                }
            }
            Spacer().frame(height: 20)
        }.frame(width: 228, height: 346)

但是效果却不尽如人意～

那么如何resize一个PickerView呢，需要用到.clipped()

struct DatePickerView: View {
    @State var dateHour: Int = 0
    @State var dateMinute: Int = 0
    var body: some View {
        VStack {

            HStack {

                HStack {
                    Picker("Hour", selection: $dateHour) {
                        ForEach(0..<24) { i in
                            Text(CommonUtil.appendZero(num: i)).frame(width: 30)
                        }
                    }.frame(width: 50).pickerStyle(WheelPickerStyle()).clipped()
                }

                Text(":")

                HStack {
                    Picker("Minute", selection: $dateMinute) {
                        ForEach(0..<60) { i in
                            Text(CommonUtil.appendZero(num: i)).frame(width: 30)
                        }
                    }.frame(width: 50).pickerStyle(WheelPickerStyle()).clipped()
                }
            }
            Spacer().frame(height: 20)
        }.frame(width: 228, height: 346)