Imports System.Threading
Imports System.Threading.Tasks
 
Public Class Form1
 
    Private cmdTask As Task
    Private cmdTaskCTS As New CancellationTokenSource
    Private cmdTaskCT As CancellationToken
 
    ''' <summary>
    ''' The CMD <see cref="System.Diagnostics.Process"/> instance.
    ''' </summary>
    Private WithEvents cmdProcess As New Process With
        {
            .EnableRaisingEvents = True,
            .StartInfo = New ProcessStartInfo With
                             {
                                .FileName = "cmd.exe",
                                .Arguments = String.Empty,
                                .RedirectStandardInput = False,
                                .RedirectStandardOutput = True,
                                .RedirectStandardError = True,
                                .UseShellExecute = False,
                                .CreateNoWindow = True
                             }
        }
 
    ''' <summary>
    ''' Gets the ping commandline arguments.
    ''' </summary>
    Private ReadOnly Property PingArguments As String
        Get
            Return String.Format("ping.exe -t ""{0}.{1}.{2}.{3}""",
                                TextBox1.Text, TextBox2.Text,
                                TextBox3.Text, TextBox4.Text)
        End Get
    End Property
 
    Private Sub btnSend_Click(ByVal sender As Object, ByVal e As EventArgs) _
    Handles btnsend.Click
 
        Me.StartTask()
 
    End Sub
 
    Private Sub CMDAutomate()
 
        With Me.cmdProcess
 
            .StartInfo.Arguments = String.Format("/C ""{0}""", Me.PingArguments)
            .Start()
            .BeginOutputReadLine()
            .BeginErrorReadLine()
            .WaitForExit(Integer.MaxValue)
 
        End With
 
    End Sub
 
    ''' <summary>
    ''' Occurs when an application writes to its redirected <see cref="System.Diagnostics.Process.StandardOutput"/> stream.
    ''' Occurs when an application writes to its redirected <see cref="System.Diagnostics.Process.StandardError"/>  stream.
    ''' </summary>
    Private Sub cmdProcess_OutputDataReceived(ByVal sender As Object, ByVal e As DataReceivedEventArgs) _
    Handles cmdProcess.OutputDataReceived,
            cmdProcess.ErrorDataReceived
 
        Select Case txtresults.InvokeRequired
 
            Case True
                txtresults.Invoke(Sub() txtresults.AppendText("" & e.Data))
                txtresults.Invoke(Sub() txtresults.AppendText(Environment.NewLine))
 
            Case Else
                txtresults.AppendText(e.Data)
                txtresults.AppendText(Environment.NewLine)
 
        End Select
 
#If DEBUG Then
        ' Debug.WriteLine(e.Data)
#End If
 
    End Sub
 
    ''' <summary>
    ''' Occurs when a <see cref="System.Diagnostics.Process"/> exits.
    ''' </summary>
    Private Sub cmdProcess_Exited(ByVal sender As Object, ByVal e As EventArgs) _
    Handles cmdProcess.Exited
 
        Debug.WriteLine(String.Format("cmdProcess has exited with exit code: {0}",
                                      DirectCast(sender, Process).ExitCode))
 
    End Sub
 
    Private Sub LinkLabel1_LinkClicked(sender As Object, e As LinkLabelLinkClickedEventArgs) _
    Handles LinkLabel1.LinkClicked
 
        ' limpio el texto de cada textbox.
        For Each tb As TextBox In Me.Controls.OfType(Of TextBox)()
            tb.Clear()
        Next tb
 
        ' cancelo la tarea en segundo plano.
        Me.CancelTask()
 
    End Sub
 
    Private Sub StartTask()
 
        Me.cmdTask = Task.Factory.StartNew(AddressOf CMDAutomate)
        Me.cmdTaskCTS = New Threading.CancellationTokenSource
        Me.cmdTaskCT = cmdTaskCTS.Token
 
    End Sub
 
    Private Sub CancelTask()
 
        ' Si el proceso no se ha detenido...
        If Not Me.cmdProcess.HasExited Then
 
            With Me.cmdProcess
                ' cancelo la lectura de los outputs.
                .CancelOutputRead()
                .CancelErrorRead()
                .Kill() ' mato el proceso (cmd.exe)
            End With
 
            ' Cancelo la tarea en segundo plano.
            Me.cmdTaskCTS.Cancel()
            ' Espero a que la tarea se haya cancelado.
            Me.cmdTask.Wait()
 
        End If
 
    End Sub
 
End Class

.WaitForExit(Integer.MaxValue)

Public Class Form1
 
    Private WithEvents dt As DataTable
 
    Private ReadOnly columns As DataColumn() =
        {
            New DataColumn("Codigo_Articulo", GetType(String)),
            New DataColumn("Descripcion", GetType(String)),
            New DataColumn("Cantidad", GetType(Integer)),
            New DataColumn("Precio", GetType(Decimal))
        }
 
    ' añadir fila
    Private Sub Button_añadir_Click() Handles Button_añadir.Click
 
        If dt Is Nothing Then
            dt = New DataTable
            dt.Columns.AddRange(columns)
            dgvCostos.DataSource = dt
            ' dgvCostos.DataBind()
        End If
 
        Dim dr As DataRow = dt.NewRow()
        dr(columns(0)) = txtCodArt.Text
        dr(columns(1)) = txtDescripcion.Text
        dr(columns(2)) = txtCantidad.Text
        dr(columns(3)) = txtPrecio.Text
        dt.Rows.Add(dr)
        dt.AcceptChanges()
 
    End Sub
 
    ' Sumar y Multiplicar
    Private Sub Button_sumar_Click(sender As Object, e As EventArgs) Handles Button_sumar.Click
 
        ' total de cantidades
        Dim sumaCantidades As Integer = (From row As DataRow In dt.Rows
                                         Select CType(row.Item(2I), Integer)).Sum
 
        ' total de precios
        Dim sumaPrecios As Integer = (From row As DataRow In dt.Rows
                                      Select CType(row.Item(3I), Integer)).Sum
 
        ' un type anónimo, el cual contiene cada DataRow, y cada "cantidad * precio" de cada DataRow.
        Dim multi = From row As DataRow In dt.Rows
                    Let multiply As Integer = CType(row.Item(2I), Integer) * CType(row.Item(3I), Integer)
 
        Dim sb As New System.Text.StringBuilder
        sb.AppendLine(String.Format("Cantidad total: {0}", CStr(sumaCantidades)))
        sb.AppendLine(String.Format("Precio total: {0}", CStr(sumaPrecios)))
        sb.AppendLine()
 
        For index As Integer = 0 To (multi.Count - 1)
 
            sb.AppendLine(String.Format("Row: {0}, Cantidad: {1}, Precio: {2}, Precio total: {3}",
                                        CStr(index),
                                        CStr(multi(index).row.Item(2I)),
                                        CStr(multi(index).row.Item(3I)),
                                        CStr(multi(index).multiply)))
 
        Next index
 
        MessageBox.Show(sb.ToString)
 
    End Sub
 
End Class

using Microsoft.VisualBasic;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
public class Form1
{
 
 
	private DataTable dt;
	private readonly DataColumn[] columns = {
		new DataColumn("Codigo_Articulo", typeof(string)),
		new DataColumn("Descripcion", typeof(string)),
		new DataColumn("Cantidad", typeof(int)),
		new DataColumn("Precio", typeof(decimal))
 
	};
	// añadir fila
 
	private void Button_añadir_Click()
	{
		this.dt = (DataTable)dgvCostos.DataSource;
 
		if (dt == null) {
			dt = new DataTable();
			dt.Columns.AddRange(columns);
			dgvCostos.DataSource = dt;
			// dgvCostos.DataBind()
		}
 
		DataRow dr = dt.NewRow();
		dr(columns(0)) = txtCodArt.Text;
		dr(columns(1)) = txtDescripcion.Text;
		dr(columns(2)) = txtCantidad.Text;
		dr(columns(3)) = txtPrecio.Text;
		dt.Rows.Add(dr);
		dt.AcceptChanges();
 
	}
 
	// Sumar y Multiplicar
 
	private void Button_sumar_Click(object sender, EventArgs e)
	{
		// total de cantidades
		int sumaCantidades = (from row in dt.RowsConvert.ToInt32(row.Item(2))).Sum;
 
		// total de precios
		int sumaPrecios = (from row in dt.RowsConvert.ToInt32(row.Item(3))).Sum;
 
		// un type anónimo, el cual contiene cada DataRow, y cada "cantidad * precio" de cada DataRow.
		dynamic multi = from row in dt.RowsConvert.ToInt32(row.Item(2)) * Convert.ToInt32(row.Item(3))int;
 
		System.Text.StringBuilder sb = new System.Text.StringBuilder();
		sb.AppendLine(string.Format("Cantidad total: {0}", Convert.ToString(sumaCantidades)));
		sb.AppendLine(string.Format("Precio total: {0}", Convert.ToString(sumaPrecios)));
		sb.AppendLine();
 
 
		for (int index = 0; index <= (multi.Count - 1); index++) {
			sb.AppendLine(string.Format("Row: {0}, Cantidad: {1}, Precio: {2}, Precio total: {3}", Convert.ToString(index), Convert.ToString(multi(index).row.Item(2)), Convert.ToString(multi(index).row.Item(3)), Convert.ToString(multi(index).multiply)));
 
		}
 
		MessageBox.Show(sb.ToString);
 
	}
 
}
 
//=======================================================
//Service provided by Telerik (www.telerik.com)
//Conversion powered by NRefactory.
//Twitter: @telerik
//Facebook: facebook.com/telerik
//=======================================================
 

#Region " TASK Example "
 
Public Class Form1
 
    ' NORMAL TASK USAGE:
    ' ------------------
    Private Task1 As Threading.Tasks.Task
    Private Task1CTS As New Threading.CancellationTokenSource
    Private Task1CT As Threading.CancellationToken = Task1CTS.Token
 
    Private Sub MyTask1(ByVal CancellationToken As Threading.CancellationToken)
 
        For x As Integer = 0 To 9999
 
            If Not CancellationToken.IsCancellationRequested Then
                Debug.Print("Task1: " & x)
            Else
                MsgBox(String.Format("Task1 Canceled at ""{0}""", x))
                Exit Sub
            End If
 
        Next x
 
    End Sub
 
    ' ANONYMOUS TASK METHOD:
    ' ---------------------
    Private Task2 As Threading.Tasks.Task
    Private Task2CTS As New Threading.CancellationTokenSource
    Private Task2CT As Threading.CancellationToken = Task2CTS.Token
 
    Private Delegate Function Task2Delegate(ByVal CancellationToken As Threading.CancellationToken)
 
    Private MyTask2 As Task2Delegate =
      Function(CancellationToken As Threading.CancellationToken) As Boolean
 
          For x As Integer = 0 To 9999
 
              If Not CancellationToken.IsCancellationRequested Then
                  Debug.Print("Task2: " & x)
              Else
                  MsgBox(String.Format("Task2 Canceled at ""{0}""", x))
                  Return False
              End If
 
          Next x
 
          Return True
 
      End Function
 
    Private Sub TaskTest() Handles MyBase.Shown
 
        ' Run an asynchronous Task.
        Task1 = Threading.Tasks.Task.Factory.StartNew(Sub() MyTask1(Task1CT), Task1CT)
 
        ' Wait 2 seconds (Just to demonstrate this example)
        Threading.Thread.Sleep(2 * 1000)
 
        ' Cancel the Task.
        Task1CTS.Cancel()
 
        ' Wait for the Task to finish the being cancelled.
        Task1.Wait()
 
        ' Show the task status
        MsgBox(Task1.Status.ToString) ' Result: RanToCompletion
 
        ' ReStart the Task1.
        Task1 = Threading.Tasks.Task.Factory.StartNew(Sub() MyTask1(Task1CT), Task1CT)
 
        ' Start the Task2
        Task2 = Threading.Tasks.Task.Factory.StartNew(Of Boolean)(Function() MyTask2(Task2CT), Task2CT)
 
        ' Wait for both Tasks to finish their execution.
        Threading.Tasks.Task.WaitAll()
 
    End Sub
 
End Class
 
#End Region

        combinations.ForEach(Sub(combination As List(Of Integer))
                                ListBox2.Items.Add(String.Join(", ", From value As Integer In combination
                                                                     Select If(value.ToString.Length = 1I,
                                                                               value.ToString.Insert(0I, "0"c),
                                                                               value.ToString)))

Public Class Form1
 
    Private Sub test() Handles MyBase.Shown
 
        ' instancio  la lista que contiene las sub-listas
        Dim lists As New List(Of List(Of Integer))
 
        ' instancio las sub-listas
        Dim list1 As New List(Of Integer) From {0, 1, 3, 4, 5, 6}
        Dim list2 As New List(Of Integer) From {0, 1, 4, 5, 6, 8}
        Dim list3 As New List(Of Integer) From {0, 1, 4, 5, 6, 9}
        Dim list4 As New List(Of Integer) From {1, 2, 4, 5, 6, 18}
        Dim list5 As New List(Of Integer) From {10, 20, 45, 88, 87, 90}
 
        ' añado las sub-listas
        lists.AddRange({list1, list2, list3, list4, list5})
 
        ' elimino las sub-listas cuyo primer elemento sea "0"
        lists.RemoveAll(Function(list As List(Of Integer)) list.First = 0)
 
        ' Compruebo las listas que han quedado...
        Dim sb As New System.Text.StringBuilder
        For Each list As List(Of Integer) In lists
            sb.AppendLine(String.Join(", ", list))
        Next
        MessageBox.Show(sb.ToString, "Listas que no se han eliminado",
                        MessageBoxButtons.OK, MessageBoxIcon.Information)
 
    End Sub
 
End Class

lists.RemoveAll(Function(list As List(Of Integer)) list.First = 0)

        Dim list As New List(Of Integer) From {0, 1, 10, 100, 2, 3, 4, 5}
        list.RemoveAll(Function(n As Integer) CStr(n).Contains(0))
 
        MsgBox(String.Join(", ", list))