在Xamarin表单中重新启动活动时保持开关值

protected override void OnCreate(Bundle savedInstanceState)
{
    base.OnCreate(savedInstanceState);
    SetContentView(Resource.Layout.activity_main);

    // 读取之前保存的开关状态
    var sharedPreferences = GetSharedPreferences("MyPrefs", FileCreationMode.Private);
    var switchValue = sharedPreferences.GetBoolean("SwitchValue", false);

    // 设置开关的值
    var switchControl = FindViewById<Switch>(Resource.Id.switchControl);
    switchControl.Checked = switchValue;

    // 监听开关状态改变事件
    switchControl.CheckedChange += (sender, e) =>
    {
        // 保存开关状态
        var editor = sharedPreferences.Edit();
        editor.PutBoolean("SwitchValue", e.IsChecked);
        editor.Apply();
    };
}