public SettingsViewModel()
{
// 由于默认值不是常量，因此需要动态注册
SettingService.Instance.RegisterSetting(this, nameof(PriorSource), null, MediaSources.First());
SettingService.Instance.RegisterSetting(this, nameof(Theme), null, ThemeList.First());
SettingService.Instance.RegisterSetting(this, nameof(ReminderSpanAhead), null, TimeSpan.FromMinutes(5));
SettingService.Instance.ApplySettingAttributes(this);
ClearCacheFiles = new DelegateCommand(async() =>
{
await CacheService.ClearCache();
await new MessageDialog("成功清空缓存", "成功").ShowAsync();
CacheFileSize = 0;
}, () => CacheFileSize > 0);
}
