Open the Control Panel
Open Administrative tools
Open Microsoft .Net Framework 1.1 Wizards
Click Adjust .Net Security
Click Next
Select Local Intranet
Change the level of trust to Full
Click Next
Click Finish

from a solution provided by Eric Moreau in Message #1039491

string MySQLString = @"Select count(*) from customer
                       where city = 'Walla Walla'";

Your first reaction might be to use this statement to fill a DataSet with a one row, one column Table in order to get the count. This would work, but why have all the overhead of a DataSet? A better approach is to use the ExecuteScalar() method instead:

OleDbConnection loConnection = new OleDbConnection(MyConnectString);
loConnection.Open();
OleDbCommand cmd = new OleDbCommand(MySQLString, loConnection);
int iCount = Convert.ToInt32(cmd.ExecuteScalar());

Note the use of Convert.ToInt32 ... this is to keep your code back-end independent, as some databases may return a count other than an integer.

from a solution provided by Çetin Basöz in Message #1005874 and Message #1006094

from a solution provided by Rick Strahl in Message #1082200

using System;
using System.Collections;
using System.Windows.Forms;

namespace MyNameSpace.MyClasses
{
   public class FormsHandler
   {
      #region Declarations
      private static ArrayList list = new ArrayList();
      #endregion

      #region Methods
      public static int Add(object o)
      {
         return list.Add(o);
      }
      public static void Remove(object o)
      {
         list.Remove(o);
      }
      public static bool Close()
      {
         int nCount = list.Count;
         while (list.Count > 0)
         {
            ((Form)list[0]).Close();
            if (list.Count == nCount)
               return false;
            else
               nCount = list.Count;
         }

         return true;
      }
      #endregion

      #region Properties
      public static ArrayList List
      {
         get {return list;}
      }
      #endregion
   }
}

Form oForm = new MyForm();
FormsHandler.Add(oForm);
oForm.Show();

// This is a menu item that exits the application

private void menuItem4_Click(object sender, System.EventArgs e)
{
   System.ComponentModel.CancelEventArgs ee = new CancelEventArgs();
   this.ClosingHandler(sender, ee);
}

// This is the ClosingHandler that will execute normally if you close the app
// by clicking on the "X"

private void ClosingHandler(object sender, System.ComponentModel.CancelEventArgs e)
{
   if (!FormsHandler.Close())
      e.Cancel = true;
   else
      Application.Exit();
}

from a solution provided by Bonnie Berent in Message #1056744