Biblioteca de código de Visual Basic .NET

[Mace Windu]

Descripción: Convierte a minúsculas una cadena.
Controles: TextBox (1), Button(1).

Código:

Public Class Form1
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.Text = "Convertir a minúsculas"
        Button1.Text = "&Convertir"
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim Cadena As String = TextBox1.Text
        TextBox1.Text = Cadena.ToLower
    End Sub
End Class

Salu2

[Mace Windu]

Descripción: Invierte una cadena.
Controles: TextBox (1), Button(1).

Código:

Public Class Form1
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.Text = "Invertir una cadena"
        Button1.Text = "&Invertir"
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        TextBox1.Text = StrReverse(TextBox1.Text)
    End Sub
End Class

Salu2

[Mace Windu]

Descripción: Muestra un número aleatorio entre 0 y el número escrito en TextBox1.
Controles: TextBox (1), Button(1).

Código:

Public Class Form1
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.Text = "Generar un número aleatorio"
        Button1.Text = "&Generar"
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim Aleatorio As Integer
        Randomize()
        Aleatorio = Rnd() * CInt(TextBox1.Text)
        MessageBox.Show("El número aleatorio es " & CStr(Aleatorio) & ".", "Al habla Mace Windu", MessageBoxButtons.OK)
    End Sub
End Class

Salu2

[Mace Windu]

Descripción: Averigua la dirección IP de tu ordenador.
Controles: TextBox (1), Button(1).

Código:

Public Class Form1
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.Text = "Averiguar IP"
        Button1.Text = "&Averiguar"
    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim Ip As Net.Dns
        Dim NombreHost As String = Ip.GetHostName
        Dim ActualHost As Net.IPHostEntry = Ip.GetHostByName(NombreHost)
        Dim DireccionIp As String = ActualHost.AddressList(0).ToString

        TextBox1.Text = "Tu dirección IP es " & DireccionIp
    End Sub
End Class

Salu2

[Mace Windu]

Descripción: Muestra si hay conexión a Internet.
Controles: TextBox (1), Button(1).

Código:

Public Class Form1
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If My.Computer.Network.IsAvailable = True Then
            TextBox1.Text = "La conexión a Internet está disponible."
        Else
            TextBox1.Text = "La conexión a Internet no está disponible."
        End If
    End Sub

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        Me.Text = "Saber si hay conexión a Internet"
        Button1.Text = "Conexión"
    End Sub
End Class

Salu2

[Rakzo-Fimbres]

Descripcion: Ejecutar un programa usando las variables de entorno (Modificar donde dice explorer.exe)
Controles: 1 Button

Código:

Public Class Form1

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim winDir As String = System.IO.Path.GetDirectoryName _
            (Environment.SystemDirectory)
        Shell(winDir & "\explorer.exe")
    End Sub
End Class

[Rakzo-Fimbres]

Descripcion: Registrar teclas para un HotKey
Controles: 1 Boton

En un modulo:

Código:

    Public Enum ModConst
        MOD_ALT = &H1
        MOD_CONTROL = &H2
        MOD_SHIFT = &H4
        MOD_WINKEY = &H8
    End Enum

    Public Class cHotKey

        Public hID As Integer
        Public hModifier As ModConst
        Public hKeyCode As Integer
        Public hAction As Integer
        Public hDescription As String

        'Constructores
        Sub New()
        End Sub
        Sub New(ByVal ID As Integer, ByVal Modifier As ModConst, ByVal KeyCode As Integer, Optional ByVal Action As Integer = 0, Optional ByVal Description As String = "")
            hID = ID
            hModifier = Modifier
            hKeyCode = KeyCode
            hAction = Action
            hDescription = Description
        End Sub

        Friend Function SetValues(ByVal ID As Integer, ByVal Modifier As ModConst, ByVal KeyCode As Integer, Optional ByVal Action As Integer = 0, Optional ByVal Description As String = "") As Boolean
            hID = ID
            hModifier = Modifier
            hKeyCode = KeyCode
            hAction = Action
            hDescription = Description
        End Function

        Public Overrides Function ToString() As String
            Return hID & "," & hModifier & "," & hKeyCode & "," & hAction & "," & hDescription
        End Function

    End Class

    Public Class HotKeysManager
        'Heredo de Form para tener el sub wndProc
        Inherits System.Windows.Forms.Form

        Private g_hWnd As Integer

        'Colección de cHotKeys donde se guardarán los datos de las hotkeys registradas
        Private g_HotKeys As New Collection

        'Hotkey Message. used in WndProc method
        Public Const WM_HOTKEY = &H312

        Public Event HotKeyPressed(ByVal oHotKey As cHotKey)

        'Constructores
        Sub New()
            g_hWnd = Me.Handle.ToInt32
        End Sub

        Private Declare Function RegisterHotKey Lib "user32" (ByVal hWnd As Integer, ByVal id As Integer, ByVal fsModifiers As ModConst, ByVal vk As Integer) As Boolean
        Private Declare Function UnregisterHotKey Lib "user32" (ByVal hWnd As Integer, ByVal id As Integer) As Boolean

        'Elimina de la colección todas las hotkeys y las desregistra
        Public Function Clear()
            Dim tmp As cHotKey
            For Each tmp In g_HotKeys
                DelHotKey(tmp.hID)
            Next
        End Function

        'Agrega una hotkey a la colección y la registra
        Public Function AddHotKey(ByVal HotKeyID As Integer, ByVal Modifer As ModConst, ByVal KeyCode As Integer, Optional ByVal Action As Integer = 0, Optional ByVal Description As String = "") As Boolean
            Dim bRet As Boolean

            'borro el elemento y lo desregistro (si existía)
            Dim tmp As cHotKey
            For Each tmp In g_HotKeys
                If tmp.hID = HotKeyID Then
                    DelHotKey(HotKeyID)
                End If
            Next

            'Registro la HotKey en el SO
            bRet = RegisterHotKey(g_hWnd, HotKeyID, Modifer, KeyCode)

            If bRet Then
                'Creo un nuevo objeto de la clase cHotKey y lo inserto a la colección
                Dim newHotKey As New cHotKey(HotKeyID, Modifer, KeyCode, Action, Description)
                g_HotKeys.Add(newHotKey, HotKeyID.ToString)
            End If
            Return bRet
        End Function

        'Eliminar una hotkey de la colección y la desregistra
        Public Function DelHotKey(ByVal HotKeyID As Integer) As Boolean
            Dim bRet As Boolean = False
            If g_HotKeys.Count > 0 Then
                bRet = UnregisterHotKey(g_hWnd, HotKeyID)
                If bRet Then
                    g_HotKeys.Remove(HotKeyID.ToString)
                End If
            End If
            Return bRet
        End Function

        'Devuelve el ítem de la colección a partir de su índice
        Public Function Item(ByVal index As Integer) As cHotKey
            Return g_HotKeys.Item(index)
        End Function
        'Devuelve el ítem de la colección a partir key
        Public Function Item(ByVal key As String) As cHotKey
            Return g_HotKeys.Item(key)
        End Function

        'Devuelve la cantidad de hotkeys en la colección
        Public Function Count() As Integer
            Return g_HotKeys.Count
        End Function

        'Aquí se reciben los mensajes (al presionar las hotkeys)
        Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
            If m.Msg = WM_HOTKEY And g_HotKeys.Count > 0 Then
                RaiseEvent HotKeyPressed(g_HotKeys(m.WParam.ToString))
            End If
            MyBase.WndProc(m)
        End Sub
    End Class

    Friend Structure POINTAPI
        Dim x As Integer
        Dim y As Integer
    End Structure

    Friend Structure Msg
        Dim hWnd As Integer
        Dim Message As Integer
        Dim wParam As Integer
        Dim lParam As Integer
        Dim time As Integer
        Dim pt As POINTAPI
    End Structure

En el form:

Código:

Public Class Form1

    Public WithEvents hk As New HotKeysManager

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        hk.AddHotKey(1, ModConst.MOD_CONTROL, Asc("Q"), 1, "Esta es la hot-key 1 (CTRL-Q)")
        hk.AddHotKey(2, ModConst.MOD_CONTROL, Asc("W"), 1, "Esta es la hot-key 2 (CTRL-W)")
    End Sub

    Private Sub hk_HotKeyPressed(ByVal oHotKey As cHotKey) Handles hk.HotKeyPressed
        MsgBox(oHotKey.hDescription)
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Button1.Text = "Registrar HotKeys (CTRL-Q y CTRL-W)"
    End Sub

End Class

Presiona Ctrl + Q / Ctrl + W
PD: Este code no recuerdo de donde lo saque, asi que no es mio.. andaba por las cochumbres de mi PC 
Salu2

[Mace Windu]

Descripción: Ejecuta cualquier archivo.
Controles: TextBox (1), Button(1).

Código:

Imports System.Diagnostics

Public Class Form1
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim Proceso As Process = New Process
        Proceso.Start(TextBox1.Text)
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.Text = "Ejecutar archivo"
        Button1.Text = "&Ejecutar"
    End Sub
End Class

Salu2

[Mace Windu]

Descripción: Muestra en minutos el tiempo que lleva encendido el ordenador.
Controles: TextBox (1), Button(1).

Código:

Imports System
Imports System.Environment

Public Class Form1
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        TextBox1.Text = "Iniciaste el ordenador hace " & (TickCount / 1000 / 60).ToString & " minutos."
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.Text = "Tiempo en ejecución del sistema"
        Button1.Text = "&Averiguar"
    End Sub
End Class

Salu2

[Mace Windu]

Descripción: Suspende la actividad de la aplicación durante x segundos (TextBox1).
Controles: TextBox (1), Button(1).

Código:

Public Class Form1
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        System.Threading.Thread.Sleep(CInt(TextBox1.Text) * 1000)
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.Text = "Suspender la actividad de la aplicación"
        Button1.Text = "&Suspender"
    End Sub
End Class

Salu2

[Mace Windu]

Descripción: Averigua el número de núcleos de tu procesador.
Controles: TextBox (1), Button(1).

Código:

Código:

Public Class Form1
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        TextBox1.Text = CStr(System.Environment.ProcessorCount)
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Me.Text = "Averiguar número de núcleos"
        Button1.Text = "&Averiguar"
    End Sub
End Class

Salu2