iOS

automatic

リスト内

struct ContentView: View {
    @State var pickerIndex: Int = 0
    var body: some View {
        Form {
            Section {
                Picker("ひらがな", selection: $pickerIndex) {
                    Text("あいうえお").tag(0)
                    Text("かきくけこ").tag(1)
                    Text("さしすせそ").tag(2)
                    Text("たちつてと").tag(3)
                    Text("なにぬねの").tag(4)
                }
                .pickerStyle(.automatic)
            }
        }
    }
}

リスト外

struct ContentView: View {
    @State var pickerIndex: Int = 0
    var body: some View {
        Picker("ひらがな", selection: $pickerIndex) {
            Text("あいうえお").tag(0)
            Text("かきくけこ").tag(1)
            Text("さしすせそ").tag(2)
            Text("たちつてと").tag(3)
            Text("なにぬねの").tag(4)
        }
        .pickerStyle(.automatic)
    }
}

注意
Pickerを配置する場所によってスタイルが変動

inline

struct ContentView: View {
    @State var pickerIndex: Int = 0
    var body: some View {
        Form {
            Section {
                Picker("ひらがな", selection: $pickerIndex) {
                    Text("あいうえお").tag(0)
                    Text("かきくけこ").tag(1)
                    Text("さしすせそ").tag(2)
                    Text("たちつてと").tag(3)
                    Text("なにぬねの").tag(4)
                }
                .pickerStyle(.inline)
            }
        }
    }
}

menu

struct ContentView: View {
    @State var pickerIndex: Int = 0
    var body: some View {
        Form {
            Section {
                Picker("ひらがな", selection: $pickerIndex) {
                    Text("あいうえお").tag(0)
                    Text("かきくけこ").tag(1)
                    Text("さしすせそ").tag(2)
                    Text("たちつてと").tag(3)
                    Text("なにぬねの").tag(4)
                }
                .pickerStyle(.menu)
            }
        }
    }
}

segmented

struct ContentView: View {
    @State var pickerIndex: Int = 0
    var body: some View {
        Form {
            Section {
                Picker("ひらがな", selection: $pickerIndex) {
                    Text("あいうえお").tag(0)
                    Text("かきくけこ").tag(1)
                    Text("さしすせそ").tag(2)
                    Text("たちつてと").tag(3)
                    Text("なにぬねの").tag(4)
                }
                .pickerStyle(.segmented)
            }
        }
    }
}

wheel

struct ContentView: View {
    @State var pickerIndex: Int = 0
    var body: some View {
        Form {
            Section {
                Picker("ひらがな", selection: $pickerIndex) {
                    Text("あいうえお").tag(0)
                    Text("かきくけこ").tag(1)
                    Text("さしすせそ").tag(2)
                    Text("たちつてと").tag(3)
                    Text("なにぬねの").tag(4)
                }
                .pickerStyle(.wheel)
            }
        }
    }
}

macOS

automatic

struct ContentView: View {
    @State var pickerIndex: Int = 0
    var body: some View {
        VStack {
            Picker("ひらがな", selection: $pickerIndex) {
                Text("あいうえお").tag(0)
                Text("かきくけこ").tag(1)
                Text("さしすせそ").tag(2)
                Text("たちつてと").tag(3)
                Text("なにぬねの").tag(4)
            }
            .pickerStyle(.automatic)
            .frame(width: 300, height: 100)
        }
        .frame(width: 600, height: 400)
    }
}

inline

struct ContentView: View {
    @State var pickerIndex: Int = 0
    var body: some View {
        VStack {
            Picker("ひらがな", selection: $pickerIndex) {
                Text("あいうえお").tag(0)
                Text("かきくけこ").tag(1)
                Text("さしすせそ").tag(2)
                Text("たちつてと").tag(3)
                Text("なにぬねの").tag(4)
            }
            .pickerStyle(.inline)
            .frame(width: 300, height: 100)
        }
        .frame(width: 600, height: 400)
    }
}

menu

struct ContentView: View {
    @State var pickerIndex: Int = 0
    var body: some View {
        VStack {
            Picker("ひらがな", selection: $pickerIndex) {
                Text("あいうえお").tag(0)
                Text("かきくけこ").tag(1)
                Text("さしすせそ").tag(2)
                Text("たちつてと").tag(3)
                Text("なにぬねの").tag(4)
            }
            .pickerStyle(.menu)
            .frame(width: 300, height: 100)
        }
        .frame(width: 600, height: 400)
    }
}

radioGroup

struct ContentView: View {
    @State var pickerIndex: Int = 0
    var body: some View {
        VStack {
            Picker("ひらがな", selection: $pickerIndex) {
                Text("あいうえお").tag(0)
                Text("かきくけこ").tag(1)
                Text("さしすせそ").tag(2)
                Text("たちつてと").tag(3)
                Text("なにぬねの").tag(4)
            }
            .pickerStyle(.radioGroup)
            .frame(width: 300, height: 100)
        }
        .frame(width: 600, height: 400)
    }
}

segmented

struct ContentView: View {
    @State var pickerIndex: Int = 0
    var body: some View {
        VStack {
            Picker("ひらがな", selection: $pickerIndex) {
                Text("あいうえお").tag(0)
                Text("かきくけこ").tag(1)
                Text("さしすせそ").tag(2)
                Text("たちつてと").tag(3)
                Text("なにぬねの").tag(4)
            }
            .pickerStyle(.segmented)
            .frame(width: 300, height: 100)
        }
        .frame(width: 600, height: 400)
    }
}