update left join

Update t 
SET 
       t.Column1=100
FROM 
       myTableA t 
LEFT JOIN 
       myTableB t2 
ON 
       t2.ID=t.ID

fuente: https://stackoverflow.com/questions/6335388/update-and-left-outer-join-statements

Validar números TextBox

If String.IsNullOrEmpty(tbnumber.Text.Trim("0")) Then
            tbnumber.Clear()
            MessageBox.Show("Ingrese un valor mayor que cero")

            Exit Sub
        Else
            Dim number As Long = 0
            Dim result As Boolean = Int64.TryParse(tbnumber.Text.Trim, number)

            If Not result Then
                MessageBox.Show("Número no válido")
            Else
                tbnumber.Text = tbnumber.Text.TrimStart("0")
            End If

            MessageBox.Show(result)
        End If

Deshabilitar copiar-pegar en un TextBox

Propiedades
ShortcutsEnabled = False

Comentarios en xml

<!--- Esto es un comentario-->

Servicio modo debug

Service1.Designer.vb

#If DEBUG Then
        Dim x As New Service1
        x.Ondebug()
#Else
#End If




' The main entry point for the process
    <MTAThread()> _
    <System.Diagnostics.DebuggerNonUserCode()> _
    Shared Sub Main()

#If DEBUG Then
        Dim debug_service As New Service1
        debug_service.Ondebug()
#Else


        Dim ServicesToRun() As System.ServiceProcess.ServiceBase

        ' More than one NT Service may run within the same process. To add
        ' another service to this process, change the following line to
        ' create a second service object. For example,
        '
        '   ServicesToRun = New System.ServiceProcess.ServiceBase () {New Service1, New MySecondUserService}
        '
        ServicesToRun = New System.ServiceProcess.ServiceBase() {New Service1}

        System.ServiceProcess.ServiceBase.Run(ServicesToRun)
#End If
    End Sub

Crear directorio

Try
            Directory.CreateDirectory("nombreDirectorio")
        Catch ex As Exception
            MessageBox.Show(ex.ToString())
        End Try

Ajustar columnas en DataGridView

AutoSizeColumnsMode = Fill

Acerca de...

Imports System.Windows.Forms
Imports System.Runtime.InteropServices

Public Class Form1

    Private Const WM_SYSCOMMAND As Integer = 274
    Private Const MF_STRING As Integer = 0
    Private Const MF_SEPARATOR As Integer = 2048

    <DllImport("user32.dll", CharSet:=CharSet.Auto, SetLastError:=True)>
    Private Shared Function GetSystemMenu(ByVal hWnd As IntPtr, ByVal bRevert As Boolean) As IntPtr
    End Function
    <DllImport("user32.dll", CharSet:=CharSet.Auto, SetLastError:=True)>
    Private Shared Function AppendMenu(ByVal hMenu As IntPtr, ByVal uFlags As Integer, ByVal uIDNewItem As Integer, ByVal lpNewItem As String) As Boolean
    End Function
    <DllImport("user32.dll", CharSet:=CharSet.Auto, SetLastError:=True)>
    Private Shared Function InsertMenu(ByVal hMenu As IntPtr, ByVal uPosition As Integer, ByVal uFlags As Integer, ByVal uIDNewItem As Integer, ByVal lpNewItem As String) As Boolean
    End Function

    Private SYSMENU_ABOUT_ID As Integer = 1

    Public Sub CustomForm()
    End Sub

    Protected Overrides Sub OnHandleCreated(ByVal e As EventArgs)
        MyBase.OnHandleCreated(e)
        Dim hSysMenu As IntPtr = GetSystemMenu(Me.Handle, False)
        AppendMenu(hSysMenu, MF_SEPARATOR, 0, String.Empty)
        AppendMenu(hSysMenu, MF_STRING, SYSMENU_ABOUT_ID, "&About…")
    End Sub

    Protected Overrides Sub WndProc(ByRef m As Message)
        MyBase.WndProc(m)
        If (m.Msg = WM_SYSCOMMAND) AndAlso (CInt(m.WParam) = SYSMENU_ABOUT_ID) Then
            MessageBox.Show("Custom About Dialog")
        End If
    End Sub
End Class



fuente: https://stackoverflow.com/questions/4615940/how-can-i-customize-the-system-menu-of-a-windows-form

Limpiar un arreglo (array)

Dim readtext() As String = File.ReadAllLines("archivo.txt")
Array.Clear(readtext, 0, readtext.Length)

fuente: https://stackoverflow.com/questions/713867/what-is-the-best-way-to-clear-an-array-of-strings

ReDim readtext(0)

ReDim Preserve

Erase array fuente

Factura de exportación electrónica

RLV - DTE Aceptado con Reparos Leves
(HED-1-835) Export.: desde el 01-12-2017 sera obligatorio informar en la seccion <OtraMoneda> el <TpoMoneda> con valor "PESO CL"

Ejemplo:
<Totales>
  <TpoMoneda>DOLAR USA</TpoMoneda>
  <MntExe>52974</MntExe>
  <MntTotal>52974</MntTotal>
</Totales>
<OtraMoneda>
  <TpoMoneda>PESO CL</TpoMoneda>
  <TpoCambio>630.41</TpoCambio>
  <MntExeOtrMnda>33395339.34</MntExeOtrMnda>
  <MntTotOtrMnda>33395339.34</MntTotOtrMnda>
</OtraMoneda>