两个列表同步 [英] Two list synchronization

问题描述

我做的两个列表之间的同步。
的IList<事件> GoogleEvents 和表< myEvent> DB.Events;

I'm doing the synchronization between the two lists. IList<Event> GoogleEvents and Table<myEvent> DB.Events;

在谷歌方面我使用的这个

String Summary,
String Description,
EventDateTime Start,
EventDateTime End,
Event.RemindersData Reminders;

在数据库端像这样

< IMG SRC =http://i.stack.imgur.com/jcmEz.pngALT =分贝事件>

我的代码是这样的。

foreach (myEvent item in DB.Events)
{
    if (item.GoogleID == "" || item.GoogleID == null)// i add event my db
    {
        //Add dbEvent to google and save id to googleid column
    }
}

foreach (Event item in myGoogleCalendar.Items)
{
    if (DB.Events.Where(o => o.GoogleID == item.Id).Count() == 0)// i add event google
    {
        //Add googleEvent to dbEvent
    }
    else
    {
        //This event also existing in two server
        myEvent dbEvent = DB.Olaylar.Where(o => o.GoogleID == item.Id).First();
        if(item.Updated.Value == dbEvent.UpdateTime) continue;//Same

        if (item.Updated.Value > dbEvent.UpdateTime)
        {
            //Google event is new 
        }
        else
        {
            //dbEvent is new 
        }

    }

}

的有一个很大的问题的我忘了删除

我应该在哪里添加删除活动的一部分，怎么样？

Where should I add deleting events part and how ?

推荐答案

的问题是不执行删除同步，但认识到，该事件是否已在一个列表中被删除或添加到其他列表

The problem is not to implement a delete synchronization, but to recognize, whether the event has been deleted in one list or added to the other list.

我建议不要删除从DB.Events列表中的事件，而是将它们标记为删除。

I recommend not to delete events from the DB.Events list, but to mark them as deleted.

因此，你需要一个标志

bool IsDeleted = false;

在您键入 myEvent 。

在谷歌列表（我假设你使用的 https://developers.google.com/google-apps/calendar/v3/reference/events ），你没有这样的标志。所以，你的算法需要有点棘手。

In Google list (I assume you use https://developers.google.com/google-apps/calendar/v3/reference/events) you don't have such a flag. So your algorithm needs to be a bit tricky.

所以，如果你在谷歌列表需要首先同步

So you need the first synchronize from the Google list

foreach (Event item in myGoogleCalendar.Items)
{
    if (DB.Events.Where(o => o.GoogleID == item.Id).Count() == 0)
    {
        // create new DB event from Google event, because since it is 
        // not in the DB.Events list, it has not been deleted there earlier, 
        // else there would be an event with IsDeleted=true
    }
    else
    {
        //This event exists in both
        myEvent dbEvent = DB.Events.Where(o => o.GoogleID == item.Id).First();
        if (dbEvent.IsDeleted)
        {
           // delete Google event, since the flag in DB.Events list shows that 
           // it existed earlier and has been deleted in DB.Events list.
        }
        else
        {
            if(item.Updated.Value == dbEvent.UpdateTime) continue;//Same

            if (item.Updated.Value > dbEvent.UpdateTime)
            {
                // update DB event
            }
            else
            {
                // update Google event
            }
        }
    }
}

然后你从同步DB.Events列表

Then your synchronize from your DB.Events list

foreach (myEvent item in DB.Events)
{
    if (!item.IsDeleted && string.IsNullOrEmpty(item.GoogleID))
    {
        // Create new Google Event from DB event
    }
    else if (!item.IsDeleted && !string.IsNullOrEmpty(item.GoogleID))
    {
        // Mark DB event as deleted
        item.IsDeleted = true;
    }
}

这工作在场景

• 您创建DB事件


• 您创建谷歌事件


• 您可以在数据库中删除事件


• 您在谷歌删除事件

• You create an event in DB
• You create an event in Google
• You delete an event in DB
• You delete an event in Google

这篇关于两个列表同步的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！