Question

I have DataTable which brings me following data from database.

• Name
• Address
• CountryID

I want to filter the data on my side by LINQ: I have a checkbox list which has countries with IDs 1, 2, 3, 4. I want to get only results of the countries that are checked. e.g. 1, 2, 4 as CountryID by LINQ. And I want to bind that to grid view.

I am using the following code:

foreach (ListItem cBox in chkGodownlst.Items)
{ 
    if (cBox.Selected)
    {
        var a = dt.AsEnumerable()
                  .Where(r => r.Field<int>("CountryID") == Convert.ToInt32(cBox.Value));
    }
}

Answer 1

Try something like this:

// Get all checked id's.
var ids = chkGodownlst.Items.OfType<ListItem>()
    .Where(cBox => cBox.Selected)
    .Select(cBox => cBox.Value)
    .ToList();

// Now get all the rows that has a CountryID in the selected id's list.
var a = dt.AsEnumerable().Where(r => 
    ids.Any(id => id == r.Field<int>("CountryID"))
);

// Create a new table.
DataTable newTable = a.CopyToDataTable();

// Now set the new table as DataSource to the GridView.