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ICollectionView multiple filter

So I have a fitler TextBox where I want to search for different type of docs in a grid the code where I have different type of columns such as: Date,DocId,ClientId.
For a search I write on a filter Textbox something like that DocId:2002 and It just work fine but when I try to make a multiple search for example DocId:2002 ClientId:201 It doesnt search because of the return it just does an infinite loop.
private void TextBoxFilter_TextChanged(object sender, TextChangedEventArgs e)
{
foreach (Match m in Regex.Matches((sender as TextBox).Text, pattern, options))
{
if (m.Value != "")
{
Func<String, String> untilSlash = (s) => { return filters[re.Match(s).Groups[1].ToString()] = re.Match(s).Groups[2].ToString(); };
untilSlash(m.Value);
}
}
ICollectionView cv = CollectionViewSource.GetDefaultView(this.DataGridDocList.ItemsSource);
if (filters.Count == 0)
{
cv.Filter = null;
}
else
{
cv.Filter = o =>
{
for (int i = 0; i < filters.Count; i++)
{
if (filters.ElementAt(i).Key == "Date")
{
if (DateVerify.Match(filters.ElementAt(i).Value).Success)
{
return (o as Document).DateCreated < Convert.ToDateTime(DateVerify.Match(filters.ElementAt(i).Value).Groups[1].ToString()) && (o as Document).DateCreated > Convert.ToDateTime(DateVerify.Match(filters.ElementAt(i).Value).Groups[2].ToString());
}
else
{
var dateString = (o as Document).DateCreated.ToString("dd/MM/yyyy", CultureInfo.InvariantCulture);
return dateString.Contains(DateVerify.Match(filters.ElementAt(i).Value).Groups[1].ToString());
}
}
if (filters.ElementAt(i).Key == "DocId")
{
return (o as Document).DocumentId.ToString().Contains(filters.ElementAt(i).Value);
}
if (filters.ElementAt(i).Key == "ClientId")
{
return (o as Document).ClientId.ToUpper().Contains(filters.ElementAt(i).Value.ToUpper());
}
}
return false;
};
filters.Clear();
}
}
So my question is how can I do an big search with all the filters at one time?
Manually I can add them 1 by 1 and it will be something like search1 && search2 && search3 but It will take too much time and It's probably not the best solution

There are many ways of building up the predicate. However my suggestion is to keep it simple and just create one method that returns true or false. It's good practice to only return once in a method.
The code below if for illustration purposes (as I'm unable to test it):
ICollectionView cv = CollectionViewSource.GetDefaultView(this.DataGridDocList.ItemsSource);
if (filters.Any())
{
cv.Filter = new Predicate<object>(PredicateFilter);
}
else
{
cv.Filter = null;
}
Then Predicate method to filter results:
public bool PredicateFilter(object docObj)
{
Document doc = docObj as Document;
var response = new List<bool>();
for (int i = 0; i < filters.Count; i++)
{
if (filters.ElementAt(i).Key == "Date")
{
if (DateVerify.Match(filters.ElementAt(i).Value).Success)
{
response.Add(doc.DateCreated < Convert.ToDateTime(DateVerify.Match(filters.ElementAt(i).Value).Groups[1].ToString()) && doc.DateCreated > Convert.ToDateTime(DateVerify.Match(filters.ElementAt(i).Value).Groups[2].ToString()));
}
else
{
var dateString = doc.DateCreated.ToString("dd/MM/yyyy", CultureInfo.InvariantCulture);
response.Add(dateString.Contains(DateVerify.Match(filters.ElementAt(i).Value).Groups[1].ToString()));
}
}
else if (filters.ElementAt(i).Key == "DocId")
{
response.Add(doc.DocumentId.ToString().Contains(filters.ElementAt(i).Value));
}
else if (filters.ElementAt(i).Key == "ClientId")
{
response.Add(doc.ClientId.ToUpper().Contains(filters.ElementAt(i).Value.ToUpper()));
}
}
return response.All(m => m); // if all filters came back with true, return 1 response of true else false.
}

How to overcome foreach loop for list object dynamically

I'm swapping my values in List Object on some conditions and update List Object value.
Currently, what I'm doing is
- Looping on each object through List
- Check If condition is net
- Swap values
public static void SwapMinMaxIfNull<T>(this IEnumerable<T> rows, string reportfor)
{
if (reportfor.Equals("Comparison"))
{
var row = rows as IEnumerable<RiskBoardDataToExport>;
try
{
if (rows.Any())
{
var Tests = row.Where(min => min.MinGaitSpeed == null && min.MaxGaitSpeed != null).ToList();
if (Tests != null)
{
foreach (RiskBoardDataToExport test in Tests)
{
test.MinGaitSpeed = test.MaxGaitSpeed;
test.MaxGaitSpeed = null;
}
}
// again check for next object
Tests = row.Where(min => min.MinTUGTime == null && min.MaxTUGTime != null).ToList();
if (Tests != null)
{
foreach (RiskBoardDataToExport test in Tests)
{
test.MinTUGTime = test.MaxTUGTime;
test.MaxTUGTime = null;
}
}
// again check for next object
Tests = row.Where(min => min.MinBergScoreSpeed == null && min.MaxBergScoreSpeed != null).ToList();
if (Tests != null)
{
foreach (RiskBoardDataToExport test in Tests)
{
test.MinBergScoreSpeed = test.MaxBergScoreSpeed;
test.MaxBergScoreSpeed = null;
}
}
//.. for brevity
}
}
}
Can I do it in better way? I know about PropertyInfo i.e. Can check property name and get value etc, but, not having any hint to get this done.
Thanks

It's not exactly what you're asking for, but you can combine the clauses in your Where statements and then have a few if statements in the body:
public static void SwapMinMaxIfNull(this IEnumerable<RiskBoardDataToExport> rows,
string reportfor)
{
if (rows = null) return;
if (reportfor.Equals("Comparison", StringComparison.OrdinalIgnoreCase))
{
foreach (var row in rows.Where(r =>
(r.MinGaitSpeed == null && r.MaxGaitSpeed != null) ||
(r.MinBergScoreSpeed == null && r.MaxBergScoreSpeed != null) ||
(r.MinBergScoreSpeed == null && r.MaxBergScoreSpeed != null)))
{
if (row.MinGaitSpeed == null)
{
row.MinGaitSpeed = row.MaxGaitSpeed;
row.MaxGaitSpeed = null;
}
if (row.MinTUGTime == null)
{
row.MinTUGTime = row.MaxTUGTime;
row.MaxTUGTime = null;
}
if (row.MinBergScoreSpeed == null)
{
row.MinBergScoreSpeed = row.MaxBergScoreSpeed;
row.MaxBergScoreSpeed = null;
}
}
}
}

As this is an operation where order of the items in the list does not matter, you can easily speed this up by parallelization (you can read up on that here).
So, what you should do, is handle this foreach loop in a parallel way and combine it with Rufus L's optimized code for the fastest result.
var rows = rows.Where(r =>
(r.MinGaitSpeed == null && r.MaxGaitSpeed != null) ||
(r.MinBergScoreSpeed == null && r.MaxBergScoreSpeed != null) ||
(r.MinBergScoreSpeed == null && r.MaxBergScoreSpeed != null))
Parallel.ForEach(rows, (row) => {
{
if (row.MinGaitSpeed == null)
{
row.MinGaitSpeed = row.MaxGaitSpeed;
row.MaxGaitSpeed = null;
}
if (row.MinTUGTime == null)
{
row.MinTUGTime = row.MaxTUGTime;
row.MaxTUGTime = null;
}
if (row.MinBergScoreSpeed == null)
{
row.MinBergScoreSpeed = row.MaxBergScoreSpeed;
row.MaxBergScoreSpeed = null;
}
}
Note that this requires the System.Threading.Tasks namespace, that's where the Parallel class is.

New transaction is not allowed because there are other threads running in the session Linq to Entity Mvc C#

I am Using Linq to Entity MVC and when I am trying to delte records from database I am getting this Exception.
New transaction is not allowed because there are other threads running in the session.
My code:
if (Request.Form["Enroll"] != null)
{
string[] selected = Request.Form["Enroll"].Split(',');
if (selected != null)
{
if (selected.Count() != 0)
{
int k = 0;
foreach (var item in selected)
{
var TraineeId = Convert.ToInt32(item[k].ToString());
var sessionid = Convert.ToInt32(Session["user"].ToString());
var id = db.EnrollTrainee.Where(i => i.TraineeID == TraineeId
&& i.TrainerID == sessionid);
if (id != null)
{
foreach (var a in id)
{
//db.Database.Connection.Close();
EnrollTrainee delete = db.EnrollTrainee.Find(a.id);
db.EnrollTrainee.Remove(delete);
db.SaveChanges(); //Getting Exception Here
}
}
k++;
}
}
}
populatelistbox();
return View();
}
Please Help.!!!
Thanks in Advance.!!!

In my case, calling the SaveChanges() less often in nested loops solves the problem:
//produces error
foreach(...) {
foreach(...) {
...
db.SaveChanges();
} }
this is my solution
//does not produce error
foreach(...) {
foreach(...) {
...
}
}
db.SaveChanges();

Got a very good solution in this nice Blog.
Solution of my problem:-
if (Request.Form["Enroll"] != null)
{
string[] selected = Request.Form["Enroll"].Split(',');
if (selected != null)
{
if (selected.Count() != 0)
{
int k = 0;
foreach (var item in selected)
{
var TraineeId = Convert.ToInt32(item[k].ToString());
var sessionid = Convert.ToInt32(Session["user"].ToString());
var id = db.EnrollTrainee.Where(i => i.TraineeID == TraineeId
&& i.TrainerID == sessionid);
var idlist = id.ToArray<EnrollTrainee>();//Added New Line
if (idlist != null)
{
foreach (var a in idlist)
{
EnrollTrainee delete = db.EnrollTrainee.Find(a.id);
db.EnrollTrainee.Remove(delete);
db.SaveChanges();
}
}
k++;
}
}
}
populatelistbox();
return View();
}

avoid Row not found or changed error

I have banners on a site. When banner showed then I increment field in DB.
This is code:
public Banner GetBanner(CategoryBanner type)
{
var banners = Database.Banners.Where(b => b.IsPublish.Value &&
b.Category.Value == (int)type &&
b.PeriodShowCountAlready < b.PeriodShowCount || b.IsPublish.Value && b.Category.Value == (int)type &&
b.ShowNext < DateTime.Now);
var count = banners.Count();
if (count != 0)
{
var skip = new Random().Next(banners.Count() - 1);
Banner banner = banners.Skip(skip).FirstOrDefault();
if (banner != null)
{
UpdatePeriodShowCountAlready(banner); // problem is inside this method
if (banner.ShowStart == null)
UpdateShowStartAndEnd(banner);
return banner;
}
}
return null;
}
private void UpdatePeriodShowCountAlready(Banner banner)
{
try
{
if (banner != null)
{
banner.PeriodShowCountAlready++;
if (banner.PeriodShowCountAlready >= banner.PeriodShowCount && banner.ShowNext < DateTime.Now)
{
banner.PeriodShowCountAlready = 0;
banner.ShowStart = null;
banner.ShowNext = null;
}
Database.SubmitChanges();
}
}
catch (Exception ex)
{
ErrorLog.GetDefault(null).Log(new Error(ex));
}
}
And, I get the following error:
System.Data.Linq.ChangeConflictException
Row not found or changed.
This error is simple to reproduce:hold down the F5 is enough for a few seconds.
I understand why this error is occur, but how to rewrite my code properly?
Thanks.

Getting NullReferenceException don't know why

I wasn't the one who coded this line of code, and I can't gt to understand whoever did it, why did this way on this line: res.Data.Find(itm => itm.Meta.ID.ToUpper() == i["MetaDataID"].ToString().ToUpper()).Value[i["LocaleID"].ToString()] = i["Value"].ToString();
And this line gives me a NullReferenceException. How can I get around it?
public static void LoadData(Value.Item _res)
{
DataTable Res = Connector.Run("SELECT * FROM Data WHERE ItemID='" + _res.ID + "'");
if (Res.Rows.Count != 0)
{
foreach (DataRow i in Res.Rows)
{
try
{
_res.Data.Find(itm => itm.Meta.ID.ToUpper() == i["MetaDataID"].ToString().ToUpper()).Value[i["LocaleID"].ToString()] = i["Value"].ToString();
}
catch (Exception)
{
_res.Data.Add(new Value.Data(
i["ID"].ToString(),
i["Value"].ToString(),
i["LocaleID"].ToString(),
i["MetaDataID"].ToString()
));
}
}
}
}
Thx a lot guys!!! Here is my working solution which hrows no Exceptions anymore!
public static void LoadData(Value.Item _res)
{
DataTable Res = Connector.Run("SELECT * FROM Data WHERE ItemID='" + _res.ID + "'");
if (Res.Rows.Count != 0)
{
foreach (DataRow i in Res.Rows)
{
bool _flagged = false;
var _result = _res.Data.Find(itm => itm.Meta.ID.ToUpper() == i["MetaDataID"].ToString().ToUpper());
if(_result != null && i["LocaleID"] != null)
{
if (i["Value"] == null || i["LocaleID"] == null || i["MetaDataID"] == null)
_flagged = true;
}
else
{
_flagged = true;
}
if (_flagged)
{
_res.Data.Add(new Value.Data(
i["ID"].ToString(),
i["Value"].ToString(),
i["LocaleID"].ToString(),
i["MetaDataID"].ToString()
));
}
//try
//{
// _res.Data.Find(itm => itm.Meta.ID.ToUpper() == i["MetaDataID"].ToString().ToUpper()).Value[i["LocaleID"].ToString()] = i["Value"].ToString();
//}
//catch (Exception)
//{
// _res.Data.Add(new Value.Data(
// i["ID"].ToString(),
// i["Value"].ToString(),
// i["LocaleID"].ToString(),
// i["MetaDataID"].ToString()
// ));
//}
}
}
}

Impossible to answer accurately without having the code under the debugger, however what is certain is that at least one of the following has a value of null:
_res.Data
itm.Meta
itm.Meta.ID
i["MetaDataID"]
i["LocaleID"]
i["Value"]

Old-skool debugging:
Break the statement down to it's consituent parts - using local variables. Step-through and find which one is null.

Check if one of the following are null:
i["MetaDataID"]
i["LocaleID"]
i["Value"]