Public Class Form1
    Dim WithEvents dtgw As New DataGridView
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Me.Controls.Add(dtgw)
        Me.Width = 510
        With dtgw
            .Size = New Size(500, 200)
            .ColumnHeadersVisible = False  'Oculta las cabeceras horizonteles
            .RowHeadersVisible = True
            .GridColor = Color.White  'Color de las rejillas
            .ColumnCount = 3 
            .Columns.Item(0).Name = "Columna 1"
            .Columns.Item(1).Name = "Columna 2"
            .Columns.Item(2).Name = "Columna 3"
            .RowCount = 10
            .RowHeadersWidth = 80
            For Index As Integer = 0 To 9
 
                .Rows.Item(Index).HeaderCell.Value = "Fila " & Index + 1
            Next
        End With
 
         For columna = 0 To 2
            For fila = 0 To 9
                dtgw.Item(columna, fila).Value = "contenido c" & columna & "- f" & fila
            Next fila
        Next columna
 
 
    End Sub
End Class

using System;
using System.Linq;
...
 

            int[] MiArray = { 10, 4, 9, 11, 4, 7, 10, 30, 11, 10 };
 
 
            foreach (var Item in MiArray)
            {
                for (int Index = MiArray.ToList().IndexOf(Item) + 1; Index <= MiArray.Length - 1; Index++)
                {
                    if (MiArray[Index] == Item) { MiArray[Index] = 0; };
                }
            }
            Console.WriteLine(String.Join(",", MiArray));
            Console.ReadLine();

10, 4, 9, 11, 0, 7, 0, 30, 0, 0

  int[] MiArray = { 10, 4, 9, 11, 4, 7, 10, 4, 4, 4 };
 
 
            for (int frtIndex = 0; frtIndex <= MiArray.Length - 1; frtIndex++)
            {
                for (int scdIndex = frtIndex + 1; scdIndex <= MiArray.Length - 1; scdIndex++)
                {
                    if (MiArray[scdIndex] == MiArray[frtIndex]) { MiArray[scdIndex] = 0; };
                }
            }
            Console.WriteLine(String.Join(",", MiArray));
            Console.ReadLine();
 
 

10, 4, 9, 11, 0, 7, 0, 0, 0, 0

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.IO;
using System.Net;
namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
 
        private void Form1_Load(object sender, EventArgs e)
        {
 
        }
 
 
        private void button1_Click(object sender, EventArgs e)
        {
            // Get the object used to communicate with the server.
            FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://www.contoso.com/test.htm");
            request.Method = WebRequestMethods.Ftp.DownloadFile;
 
            // This example assumes the FTP site uses anonymous logon.
            request.Credentials = new NetworkCredential("anonymous","janeDoe@contoso.com");
 
            FtpWebResponse response = (FtpWebResponse)request.GetResponse();
 
            Stream responseStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(responseStream);
           textBox1.Text= (reader.ReadToEnd());
 
 
            reader.Close();
            response.Close();  
 
        }
 
        private void button2_Click(object sender, EventArgs e)
        {
            byte[] Data = System.Text.Encoding.Unicode.GetBytes(textBox1.Text);
            FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://www.contoso.com/test.htm");
            request.Method = WebRequestMethods.Ftp.UploadFile;
            request.ContentLength = Data.Length;
            request.Credentials = new NetworkCredential("anonymous","janeDoe@contoso.com");
            Stream requestStream = request.GetRequestStream();
            requestStream.Write(Data, 0, Data.Length);
            requestStream.Close();
            FtpWebResponse response = (FtpWebResponse)request.GetResponse();
            response.Close();
        }
    }
}