C#：如何从谷歌日历上获得免费时段

using Google.Apis.Auth.OAuth2;
using Google.Apis.Calendar.v3;
using Google.Apis.Calendar.v3.Data;
using Google.Apis.Services;

// ...

string apiKey = "YOUR_API_KEY";
string calendarId = "YOUR_CALENDAR_ID";

var credential = new GoogleCredential().CreateScoped(CalendarService.Scope.Calendar);
var service = new CalendarService(new BaseClientService.Initializer()
{
    HttpClientInitializer = credential,
    ApplicationName = "Your Application Name"
});

// ...

EventsResource.ListRequest request = service.Events.List(calendarId);
request.TimeMin = DateTime.Now;
request.ShowDeleted = false;
request.SingleEvents = true;
request.OrderBy = EventsResource.ListRequest.OrderByEnum.StartTime;

Events events = request.Execute();

foreach (var item in events.Items)
{
    if (item.Transparency == "transparent")
    {
        // 这是一个免费时段
        // 可以根据需要处理该免费时段的开始时间和结束时间
    }
}