Why getting data with Entity Framwork is slow? [closed]

问题

I am creating a Windows forms program with C# and Entity Framework. I want to fetch data from SQL database and do some processing after fetching it.

Everything is good but the performance is too bad with too slow speed even with little data. My code is below and I want to know what is wrong with my code.

I searched a lot but nothing found helpful.

Thanks in advance

private readonly BarForooEntities1 _barforoosh = new BarForooEntities1();

public void Getdataforoosh()
{
    BindingSource b = new BindingSource();

    b.DataSource = (from m in _barforoosh.RadifsSendCenter
                    where m.Receive == false
                    select new
                           {
                               m.id_rec, m.Radifkolsal,
                               m.Dates, m.DateErsal,
                               m.TimeErsal, m.Karkhane,
                               m.Namekala, m.Vazn,
                               m.Bandal, m.Dobaskul,
                               m.OldYear, m.Sal,
                               m.del, m.edit, m.Daryaft,
                               m.Shobe, m.Greid, m.TedadBas, 
                               m.Rahgiry, m.Tozih, m.NoeShemsh, 
                               m.Metrazh, m.Keyfiat, m.Address,
                               m.City, m.Karbar, m.CodeKala,
                               m.CodeGoruh, m.CodeKG, m.CodeGreid,
                               m.Tel, m.ShenaseMeli, m.Sefaresh,
                               m.Tolid, m.Shenase, }).ToList();
    dataGridView1.DataSource = b;

    for (int i = 0; i < dataGridView1.RowCount; i++)
    {
        int c = Convert.ToInt32(dataGridView1.Rows[i].Cells[0].Value);

        var f = (from a in _barforoosh.RadifsSendCenter
                 where a.id_rec == c
                 select a).SingleOrDefault();
        f.Receive= true;
        _barforoosh.SaveChanges();
    }
}

回答1:

Put SaveChanges method outside of for loop:

for (int i = 0; i < dataGridView1.RowCount; i++)
{
}
_barforoosh.SaveChanges();

来源：https://stackoverflow.com/questions/37096509/why-getting-data-with-entity-framwork-is-slow

标签

entity-framework

linq-to-entities