Question

I’ve a datagridview which should be fill from a sqlserver Table.

        SqlConnection SqlConnectionInstance = new SqlConnection(WinLogin.connectinStringSecure);
        SqlConnectionInstance.Open();
        SqlCommand sqlCommandInstance = new SqlCommand("Select * From T_Kala", SqlConnectionInstance);
        SqlDataAdapter SqlDataAdapterInstance = new SqlDataAdapter("Select * From T_Kala", SqlConnectionInstance);
        DataTable dt = new DataTable("Employee"); 

but visual studio can not Identify the DataTable!

Error :

The type or namespace name ‘DataTable’ could not be found (are you
missing a using directive or an assembly reference?)

Answer 1

Check for the System.Data reference in the references list. It should be added by default, but it could have been removed.

If it exists, make sure you have the using System.Data; declaration at the top of your file.