C#

WebClient LobjWebClient = new WebClient();
string LstrData = LobjWebClient.DownloadString("http://www.google.com");

using System.Data.SqlClient;

public SqlConnection con = null;
SqlDataAdapter da = new SqlDataAdapter();
/* for the connection
String conStr = @"Data Source=Database Path;" +
                    "AttachDbFilename=" + input1 +
                    ";Integrated Security=True;" +
                    "Connect Timeout=30; User Instance=True";
            con = new SqlConnection(conStr);
/* to update the database using stored procedure

SqlCommand cmd = new SqlCommand();
            cmd.Connection = con;
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.CommandText = "Procedure Name";
            cmd.Parameters.Add("@a", SqlDbType.VarChar).Value = "xxx";
            MessageBox.Show("Employee Removed", "Successfull",);
              
                cmd.ExecuteScalar();

class DllWrapper
{
       ...

       [DllImport(@"libtest.dll")]
       private static extern void mlfTest(int num, ref IntPtr theOutput, [In]IntPtr theInput);
       ...

       public static double CallDLL(string input)
       {
           ...
           double[] ans = new double[1];
          
           GCHandle gch = GCHandle.Alloc(ans);

           //initialize libraries
           ...          

           //initialize arguments
           IntPtr inVal = mxCreateString(input);
           IntPtr outVal = IntPtr.Zero;
           outVal = Marshal.UnsafeAddrOfPinnedArrayElement(ans, 0);
                        
           //call library function
           mlfTest(1, ref outVal, inVal);
            
           //get return value        
           Marshal.Copy(mxGetPr(outVal), ans, 0, 1);
                        
           //terminate libraries
           ...
                        
           gch.Free();
           return ans[0];
       }
}


static void Main(string[] args)
{
    string path = "input";

    ....

    for (int i = 0; i < 3;  i++)
    {
        double retDouble = DllWrapper.CallDLL(path);

        Console.WriteLine("the return value is : " + retDouble);
	i++;
    }
}