System.InvalidOperationException：'集合已被修改;枚举操作可能无法执行。 [英] System.InvalidOperationException: 'Collection was modified; enumeration operation may not execute.'
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问题描述
我正在创建一个应用程序，用于将数据存储到数据库中的API。
我低于此错误。
" System.InvalidOperationException：'集合已被修改;枚举操作可能无法执行。'"
我的代码是
public static void GetAllInfluencers（）
{
sw.Start（）;
列表< InfluencerHelperModel> influencerHelperModelList = new List< InfluencerHelperModel>（）;
使用（TuesdayAppEntities dataContext = new TuesdayAppEntities（））
{
schdulerJob =（from c in dataContext.SchdulerJobs.AsEnumerable（）select c）.FirstOrDefault（）;
do
{
List< ImportedInfluencer> partilaInfluencers =（from datacer in dataContext.ImportedInfluencers.AsEnumerable（）select influencer）.Skip（offset）.Take（limit）.ToList（）;
列表<任务> allTasks = new List< Task>（）;
Console.WriteLine（" cycle begin"）;
foreach（partilaInfluencers中的ImportedInfluencer影响者）
{
InfluencerHelperModel influencerHelperModel = new InfluencerHelperModel（）;
influencerHelperModel.influencer = influencer;
influencerHelperModel.serachListResponses = new List< Google.Apis.YouTube.v3.Data.SearchResult>（）;
influencerHelperModel.youtubeSubscriberCount = string.Empty;
influencerHelperModel.channelListResponse = new Google.Apis.YouTube.v3.Data.ChannelListResponse（）;
influencerHelperModel.statusList = new List< LinqToTwitter.Status>（）;
influencerHelperModel.user = new LinqToTwitter.User（）;
influencerHelperModel.tumblrPosts = new List< Post>（）;
allTasks.Add（Task.Factory.StartNew（（）=> {new YoutubeHelper（）。GetData（influencerHelperModel，schdulerJob）;}）。ContinueWith（t => UpdateAll （influencerHelperModelList.ToList（））））;
allTasks.Add（Task.Factory.StartNew（（）=> {new TwitterHelper（）。GetData（influencerHelperModel，schdulerJob）;}）。ContinueWith（t2 => UpdateAll（influencerHelperModelList.ToList（））） ）;
allTasks.Add（Task.Factory.StartNew（（）=> {new TumblrHelper（）。GetData（influencerHelperModel，schdulerJob）; UpdateAll（influencerHelperModelList）;}）。ContinueWith（t3 => UpdateAll（influencerHelperModelList。 ToList（））））;
influencerHelperModelList.Add（influencerHelperModel）;
}
Task.WaitAll（allTasks.ToArray（））;
Console.WriteLine（" cycle finished"）;
offset = offset + limit;
if（offset> dataContext.ImportedInfluencers.Count（））
{
break;
}
} while（true）;
// SchdulerJob schdulerUpdateJob = new SchdulerJob（）;
// schdulerUpdateJob =（来自c中的dataContext.SchdulerJobs.AsEnumerable（）select c）.FirstOrDefault（）;
// if（schdulerUpdateJob == null || schdulerUpdateJob.WeeklyJobLastRun == null || schdulerUpdateJob.WeeklyJobLastRun.Value.AddDays（7）< = DateTime.Now）
// {
// schdulerUpdateJob.WeeklyJobLastRun = DateTime.Now;
// dataContext.SaveChanges（）;
//}
Console.WriteLine（sw.ElapsedMilliseconds / 1000 +" seconds"）;
}
}
首先执行任务后，我们将数据写入数据库中lock 线程功能。请参阅代码。
public static void UpdateAll（List< InfluencerHelperModel> influencerHelperModelList）
{
lock（influencerHelperModelList）
{
使用（TuesdayAppEntities dataContext = new TuesdayAppEntities（））
{
foreach（InflucerHelperModel influencerModel in influencerHelperModelList）
{
foreach（SearchResult searchResult in influencerModel.serachListResponses）
{
if（！dataContext.YoutubePosts.Any（i => i.VideoId == searchResult.Id.VideoId））
{
YoutubePost youtubePost = new YoutubePost（）;
youtubePost.VideoId = searchResult.Id.VideoId;
youtubePost.VideoUrl = string.Format（" https://www.youtube.com/watch?v = {0}"，searchResult.Id.VideoId）;
youtubePost.Title = searchResult.Snippet.Title;
youtubePost.CreatedDate = searchResult.Snippet.PublishedAt;
youtubePost.InfluencersId = influencerModel.influencer.Id;
youtubePost.Description = searchResult.Snippet.Description;
dataContext.YoutubePosts.Add（youtubePost）;
dataContext.SaveChanges（）;
}
}
foreach（influencerModel.statusList中的状态）
{
string statusId = status.StatusID.ToString（） ;
if（！dataContext.TwitterPosts.Any（i => i.TweetId == statusId））
{
TwitterPost twitterPost = new TwitterPost（）;
twitterPost.tweet = status.Text;
twitterPost.TweetId = status.StatusID.ToString（）;
twitterPost.InfluencerId = influencerModel.influencer.Id;
twitterPost.CreatedDate = status.CreatedAt;
dataContext.TwitterPosts.Add（twitterPost）;
dataContext.SaveChanges（）;
}
}
foreach（InflucerModel.tumblrPosts中的帖子）
{
string Id = post.Id的ToString（）;
if（！dataContext.TumblrPosts.Any（i => i.postId == Id））
{
TumblrPost tumblrPost = new TumblrPost（）;
tumblrPost.post = post.Body;
tumblrPost.InfluencerId = influencerModel.influencer.Id;
tumblrPost.postId = post.Id.ToString（）;
tumblrPost.postUrl = post.PostUrl;
tumblrPost.createdDate = Convert.ToDateTime（post.Date）;
dataContext.TumblrPosts.Add（tumblrPost）;
dataContext.SaveChanges（）;
}
}
ImportedInfluencer uInfluencer = new ImportedInfluencer（）;
uInfluencer =（来自dataContext.ImportedInfluencers.AsEnumerable（）中的c，其中c.Id == influencerModel.influencer.Id select c）.FirstOrDefault（）;
uInfluencer.mostReleventNumberOfFollowersYoutube = influencerModel.youtubeSubscriberCount;
uInfluencer.youtubeAvatar =（（influencerModel.channelListResponse == null）||（influencerModel.channelListResponse.Items == null）|| influencerModel.channelListResponse.Items.Count == 0）？
influencerModel。 user.ProfileImageUrl：influencerModel.channelListResponse.Items [0] .Snippet.Thumbnails.High.Url）;
uInfluencer.channelCreationDate =（（influencerModel.channelListResponse == null）||（influencerModel.channelListResponse.Items == null）||（influencerModel.channelListResponse.Items.Count == 0））？ null：influencerModel.channelListResponse.Items [0] .Snippet.PublishedAt;
uInfluencer.mostReleventNumberOfFollowersTwitter = influencerModel.user.FollowersCount.ToString（）;
uInfluencer.twitterAccCreationDate = influencerModel.user.CreatedAt;
dataContext.SaveChanges（）;
}
}
}
}
我的错误的解决方案是什么，以及增加流程时间的最佳方法是什么。
谢谢
解决方案
它是哪一行？
I am creating one app for storing the data to the API in to the data base.
I am getting below this errror.
"System.InvalidOperationException: 'Collection was modified; enumeration operation may not execute.'"
My code is
public static void GetAllInfluencers()
{
sw.Start();
List<InfluencerHelperModel> influencerHelperModelList = new List<InfluencerHelperModel>();
using (TuesdayAppEntities dataContext = new TuesdayAppEntities())
{
schdulerJob = (from c in dataContext.SchdulerJobs.AsEnumerable() select c).FirstOrDefault();
do
{
List<ImportedInfluencer> partilaInfluencers = (from influencer in dataContext.ImportedInfluencers.AsEnumerable() select influencer).Skip(offset).Take(limit).ToList();
List<Task> allTasks = new List<Task>();
Console.WriteLine("cycle begin");
foreach (ImportedInfluencer influencer in partilaInfluencers)
{
InfluencerHelperModel influencerHelperModel = new InfluencerHelperModel();
influencerHelperModel.influencer = influencer;
influencerHelperModel.serachListResponses = new List<Google.Apis.YouTube.v3.Data.SearchResult>();
influencerHelperModel.youtubeSubscriberCount = string.Empty;
influencerHelperModel.channelListResponse = new Google.Apis.YouTube.v3.Data.ChannelListResponse();
influencerHelperModel.statusList = new List<LinqToTwitter.Status>();
influencerHelperModel.user = new LinqToTwitter.User();
influencerHelperModel.tumblrPosts = new List<Post>();
allTasks.Add(Task.Factory.StartNew(() => { new YoutubeHelper().GetData(influencerHelperModel, schdulerJob);}).ContinueWith(t=> UpdateAll(influencerHelperModelList.ToList())));
allTasks.Add(Task.Factory.StartNew(() => { new TwitterHelper().GetData(influencerHelperModel, schdulerJob); }).ContinueWith(t2 => UpdateAll(influencerHelperModelList.ToList())));
allTasks.Add(Task.Factory.StartNew(() => { new TumblrHelper().GetData(influencerHelperModel, schdulerJob); UpdateAll(influencerHelperModelList); }).ContinueWith(t3 => UpdateAll(influencerHelperModelList.ToList())));
influencerHelperModelList.Add(influencerHelperModel);
}
Task.WaitAll(allTasks.ToArray());
Console.WriteLine("cycle finished");
offset = offset + limit;
if (offset > dataContext.ImportedInfluencers.Count())
{
break;
}
} while (true);
//SchdulerJob schdulerUpdateJob = new SchdulerJob();
//schdulerUpdateJob = (from c in dataContext.SchdulerJobs.AsEnumerable() select c).FirstOrDefault();
//if (schdulerUpdateJob == null || schdulerUpdateJob.WeeklyJobLastRun == null || schdulerUpdateJob.WeeklyJobLastRun.Value.AddDays(7) <= DateTime.Now)
//{
// schdulerUpdateJob.WeeklyJobLastRun = DateTime.Now;
// dataContext.SaveChanges();
//}
Console.WriteLine(sw.ElapsedMilliseconds / 1000 + " seconds");
}
}After execution the task first we are writing the data into the database by the lock thread feature. See the code.
public static void UpdateAll(List<InfluencerHelperModel> influencerHelperModelList)
{
lock (influencerHelperModelList)
{
using (TuesdayAppEntities dataContext = new TuesdayAppEntities())
{
foreach (InfluencerHelperModel influencerModel in influencerHelperModelList)
{
foreach (SearchResult searchResult in influencerModel.serachListResponses)
{
if (!dataContext.YoutubePosts.Any(i => i.VideoId == searchResult.Id.VideoId))
{
YoutubePost youtubePost = new YoutubePost();
youtubePost.VideoId = searchResult.Id.VideoId;
youtubePost.VideoUrl = string.Format("https://www.youtube.com/watch?v={0}", searchResult.Id.VideoId);
youtubePost.Title = searchResult.Snippet.Title;
youtubePost.CreatedDate = searchResult.Snippet.PublishedAt;
youtubePost.InfluencersId = influencerModel.influencer.Id;
youtubePost.Description = searchResult.Snippet.Description;
dataContext.YoutubePosts.Add(youtubePost);
dataContext.SaveChanges();
}
}
foreach (Status status in influencerModel.statusList)
{
string statusId = status.StatusID.ToString();
if (!dataContext.TwitterPosts.Any(i => i.TweetId == statusId))
{
TwitterPost twitterPost = new TwitterPost();
twitterPost.tweet = status.Text;
twitterPost.TweetId = status.StatusID.ToString();
twitterPost.InfluencerId = influencerModel.influencer.Id;
twitterPost.CreatedDate = status.CreatedAt;
dataContext.TwitterPosts.Add(twitterPost);
dataContext.SaveChanges();
}
}
foreach (Post post in influencerModel.tumblrPosts)
{
string Id = post.Id.ToString();
if (!dataContext.TumblrPosts.Any(i => i.postId == Id))
{
TumblrPost tumblrPost = new TumblrPost();
tumblrPost.post = post.Body;
tumblrPost.InfluencerId = influencerModel.influencer.Id;
tumblrPost.postId = post.Id.ToString();
tumblrPost.postUrl = post.PostUrl;
tumblrPost.createdDate = Convert.ToDateTime(post.Date);
dataContext.TumblrPosts.Add(tumblrPost);
dataContext.SaveChanges();
}
}
ImportedInfluencer uInfluencer = new ImportedInfluencer();
uInfluencer = (from c in dataContext.ImportedInfluencers.AsEnumerable() where c.Id == influencerModel.influencer.Id select c).FirstOrDefault();
uInfluencer.mostReleventNumberOfFollowersYoutube = influencerModel.youtubeSubscriberCount;
uInfluencer.youtubeAvatar = (((influencerModel.channelListResponse == null) || (influencerModel.channelListResponse.Items == null) || influencerModel.channelListResponse.Items.Count == 0) ?
influencerModel.user.ProfileImageUrl : influencerModel.channelListResponse.Items[0].Snippet.Thumbnails.High.Url);
uInfluencer.channelCreationDate = ((influencerModel.channelListResponse == null) || (influencerModel.channelListResponse.Items == null) || (influencerModel.channelListResponse.Items.Count == 0)) ? null : influencerModel.channelListResponse.Items[0].Snippet.PublishedAt;
uInfluencer.mostReleventNumberOfFollowersTwitter = influencerModel.user.FollowersCount.ToString();
uInfluencer.twitterAccCreationDate = influencerModel.user.CreatedAt;
dataContext.SaveChanges();
}
}
}
}
what is the solution of my error and what is the best way to increase the time of process.
thanks
解决方案
Which line is it?
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