Skip Function repeating values while appending in View - asp.net-mvc

Question

I am trying to use skip in mvc4 project so that previous value should not repeated while it append in the Razor view but i am getting same value after some value
here is my code :
var planetfeedsOrder = from a in db.PlanetFeeds
where a.PlanetFeedOwnerId == id || a.PlanetFeedPosterId ==id
&& a.CurrentState != 1
join c in db.Graphs on a.PlanetFeedItemGraphId equals c.GraphID
join u in db.UserInfos on a.PlanetFeedOwnerId equals u.UserInfoID
orderby a.PostDate descending
select new UserInfoViewModel
{
AvatarURL = u.AvatarURL,
UserName=u.FirstName +" "+u.LastName,
GraphItemDescription = c.GraphItemDescription,
GraphItemURL = c.GraphItemURL,
GraphItemUserFullName = c.GraphItemUserFullName,
ItemSummary = c.ItemSummary,
GraphItemThumbUrl = c.GraphItemThumbUrl,
GraphID = c.GraphID,
ItemType = c.ItemType,
ItemUserID = c.ItemUserID,
GraphItemTitle = c.GraphItemTitle,
isRootFeed = a.isRootFeed,
PostDate = a.PostDate,
CommentCount = c.CountResponses,
CountReactions = c.CountPositiveReactions,
CountReaction = c.CountNegativeReactions,
ItemID = c.ItemID,
UserLevel =u.UserLevel,
CurrentState = a.CurrentState,
RecieverUserAvatarURL = c.Address
};
return PartialView("_PlanetfeedPartial", planetfeedsOrder.Skip(SkipCount).Take(itemCount).ToList());
and here is ajax view where i am trying to append it :
$.ajax(
{
type: "Post",
url: "/PlanetFeed/PlanetfeedPartial",
dataType: "html",
data: { id: planetFeedOwnerId, filterType: filterType, taggedItemGraphId: taggedItemGraphId, itemCount: itemCount,skipCount: SkipCount }, //"feedGraphId=10696",
success: function (data) {
var div = $('.planetFeed:last');
$('.planetFeed').removeClass('.tile-group');
SkipCount = itemCount+2;
div.after(data);
var bigDivCount = $('.tile-group').length;
var bigDivWidth = bigDivCount * 486;
$('.tile-area').css({ 'width': bigDivWidth });

Answer 1

Based on your code and subsequent comments if the initial values of itemCount and skipCount are zero then in the first call (note I have substituted variables with the actual values in the data parameter so its easier to see what will be returned)
itemCount = itemCount + 5; // itemCount = 0 + 5 = 5
data: { skipCount: 0, itemCount: 5 } // returns items 1-5
skipCount = itemCount + 5; // skipCount = 5 + 5 = 10;
second call
itemCount = itemCount + 5; // itemCount = 5 + 5 = 10;
data: { skipCount: 10, itemCount: 10 } // returns items 11-20 (items 6-10 missed)
skipCount = itemCount + 5; // skipCount = 10 + 5 = 15;
third call
itemCount = itemCount + 5; // itemCount = 10 + 5 = 15;
data: { skipCount: 15, itemCount: 15 } // returns items 16-30 (items 16-20 repeated)
skipCount = itemCount + 5; // skipCount = 15 + 5 = 20;
You need to change the way you set the value of skip count and use skipCount = skipCount + itemCount;
first call
itemCount = itemCount + 5; // itemCount = 0 + 5 = 5
data: { skipCount: 0, itemCount: 5 } // returns items 1-5
skipCount = skipCount + itemCount; // skipCount = 0 + 5 = 5;
second call
itemCount = itemCount + 5; // itemCount = 5 + 5 = 10;
data: { skipCount: 5, itemCount: 10 } // returns items 6-15
skipCount = skipCount + itemCount; // skipCount = 5 + 10 = 15;
third call
itemCount = itemCount + 5; // itemCount = 10 + 5 = 15;
data: { skipCount: 15, itemCount: 15 } // returns items 16-30
skipCount = skipCount + itemCount; // skipCount = 15 + 15 = 30;
forth call
itemCount = itemCount + 5; // itemCount = 15 + 5 = 20;
data: { skipCount: 30, itemCount: 20 } // returns items 31-50
skipCount = skipCount + itemCount; // skipCount = 30 + 20 = 50;