Console.WriteLine(format: "Message: {0}", arg0: "Hello World!");

string str = string.Format("{0}+{0}={1}", "Uno", "Dos");

string str = "Hola, ¿cómo estás?.";
 
str = str.Substring(0, str.TrimEnd(' ').LastIndexOf(' ')); // "Hola, ¿cómo"

c:\Users\<username>\AppData\Local o Roaming\<companyname>\<appdomainname>_<eid>_<hash>\<verison>

C:\Users\Administrador\AppData\Local\ElektroStudios\MasterMusik_Reports.exe_Url_q2a441mf5bc330sftjmvcdv30vohiv0o\2.0.0.0\user.config

Dim value As Integer = 0
 
Select Case value
 
    Case Is = 0
        ' Activar aplicaciones.
 
    Case Is = 1
        ' Denegar aplicaciones.
 
    Case Else
        ' ...
 
End Select

    ''' <remarks>
    ''' *****************************************************************
    ''' Title : Get CPU Identifier
    ''' Author: Elektro
    ''' Date  : 03-June-2015
    ''' 
    ''' Required Namespaces:
    ''' <see cref="System.Management"/>
    ''' 
    ''' Usage Example: 
    ''' Dim Value as String = GetCpuId()
    ''' *****************************************************************
    ''' </remarks>
    ''' <summary>
    ''' Gets the motherboard ID of the current computer machine.
    ''' </summary>
    ''' <returns>The motherboard ID.</returns>
    Public Shared Function GetCpuId() As String
 
        Using wmi As New ManagementObjectSearcher("select ProcessorID from Win32_Processor")
 
            Using query As ManagementObjectCollection = wmi.Get
 
                Return DirectCast(query(0), ManagementObject).Properties("ProcessorID").Value.ToString
 
            End Using
 
        End Using
 
    End Function

    ''' <remarks>
    ''' *****************************************************************
    ''' Title : Get Motherboard Identifier
    ''' Author: Elektro
    ''' Date  : 03-June-2015
    '''
    ''' Required Namespaces:
    ''' <see cref="System.Management"/>
    ''' 
    ''' Usage Example: 
    ''' MsgBox(GetMotherboardId)
    ''' *****************************************************************
    ''' </remarks>
    ''' <summary>
    ''' Gets the motherboard ID of the current computer machine.
    ''' </summary>
    ''' <returns>The motherboard ID.</returns>
    Public Shared Function GetMotherboardId() As String
 
        Using wmi As New ManagementObjectSearcher("select SerialNumber from Win32_BaseBoard")
 
            Using query As ManagementObjectCollection = wmi.Get
 
                Return DirectCast(query(0), ManagementObject).Properties("SerialNumber").Value.ToString
 
            End Using
 
        End Using
 
    End Function

    ''' <remarks>
    ''' *****************************************************************
    ''' Title : AES Encryptor
    ''' Author: Elektro
    ''' Date  : 03-June-2015
    ''' 
    ''' Required Namespaces:
    ''' <see cref="System.IO"/>
    ''' <see cref="System.Security.Cryptography"/>
    ''' <see cref="System.Text"/>
    ''' 
    ''' Usage Example: 
    ''' Dim encrypted As String = AESEncryptor("Hello World!", key:="My Encryption Key", size:=128)
    ''' *****************************************************************
    ''' </remarks>
    ''' <summary>
    ''' Encrypts an string using AES algorithm.
    ''' </summary>
    ''' <param name="str">The string to encrypt.</param>
    ''' <param name="key">The encryption key.</param>
    ''' <param name="size">The key size. 128, 192 or 256 bits.</param>
    ''' <param name="salt">The key salt.</param>
    ''' <param name="mode">The encryption mode.</param>
    ''' <returns>The encrypted string.</returns>
    Public Function AESEncryptor(ByVal str As String,
                                 ByVal key As String,
                                 ByVal size As Integer,
                                 Optional ByVal salt As Byte() = Nothing,
                                 Optional ByVal mode As CipherMode = CipherMode.ECB) As String
 
        If (size <> 128) AndAlso (size <> 192) AndAlso (size <> 256) Then
            Throw New ArgumentException(message:="Key size for this algorithm should be 128, 192 or 256.", paramName:="keySize")
 
        ElseIf (salt IsNot Nothing) AndAlso (salt.Length < 8) Then
            Throw New ArgumentException(message:="Salt should contain at least 8 bytes.", paramName:="salt")
 
        ElseIf salt Is Nothing Then
            salt = {&H49, &H76, &H61, &H6E, &H20, &H4D, &H65, &H64}
 
        End If
 
        Using crypto As Aes = Aes.Create()
 
            Dim pdb As Rfc2898DeriveBytes = New Rfc2898DeriveBytes(key, salt:=salt)
 
            crypto.KeySize = size ' 128, 192 or 256 Bits.
            crypto.Key = pdb.GetBytes(cb:=(size \ 8)) ' 16, 24, or 32 or Bytes (128, 192 or 256 Bits).
            crypto.IV = pdb.GetBytes(cb:=16) ' 16 Bytes (128 Bits).
            crypto.Mode = mode
 
            Using ms As New MemoryStream()
 
                Using cs As New CryptoStream(ms, crypto.CreateEncryptor(), CryptoStreamMode.Write)
 
                    Dim strBytes As Byte() = Encoding.Unicode.GetBytes(str)
                    cs.Write(strBytes, 0, strBytes.Length)
                    cs.Close()
 
                End Using
 
                Return Convert.ToBase64String(ms.ToArray)
 
            End Using
 
        End Using
 
    End Function
 
    ''' <remarks>
    ''' *****************************************************************
    ''' Title : AES Decryptor
    ''' Author: Elektro
    ''' Date  : 03-June-2015
    ''' 
    ''' Required Namespaces:
    ''' <see cref="System.IO"/>
    ''' <see cref="System.Security.Cryptography"/>
    ''' <see cref="System.Text"/>
    ''' 
    ''' Usage Example: 
    ''' Dim decrypted As String = AESDecryptor("JRVQnb2q7f3BtIDaq5Tdcqu2+2GYGEMLyQrBT9mMjgw=", key:="My Encryption Key", size:=128)
    ''' *****************************************************************
    ''' </remarks>
    ''' <summary>
    ''' Decrypts a previously encrypted string using AES algorithm.
    ''' </summary>
    ''' <param name="str">The encrypted string to decrypt.</param>
    ''' <param name="key">The key used for encryption.</param>
    ''' <param name="size">The key size used for encryption. 128, 192 or 256 bits.</param>
    ''' <param name="salt">The key salt used for encryption.</param>
    ''' <param name="mode">The encryption mode.</param>
    ''' <returns>The decrypted string.</returns>
    Public Function AESDecryptor(ByVal str As String,
                                 ByVal key As String,
                                 ByVal size As Integer,
                                 Optional ByVal salt As Byte() = Nothing,
                                 Optional ByVal mode As CipherMode = CipherMode.ECB) As String
 
        If (size <> 128) AndAlso (size <> 192) AndAlso (size <> 256) Then
            Throw New ArgumentException(message:="Key size for this algorithm should be 128, 192 or 256.", paramName:="keySize")
 
        ElseIf (salt IsNot Nothing) AndAlso (salt.Length < 8) Then
            Throw New ArgumentException(message:="Salt should contain at least 8 bytes.", paramName:="salt")
 
        ElseIf salt Is Nothing Then
            salt = {&H49, &H76, &H61, &H6E, &H20, &H4D, &H65, &H64}
 
        End If
 
        Using crypto As Aes = Aes.Create()
 
            Dim pdb As New Rfc2898DeriveBytes(key, salt)
 
            crypto.KeySize = size ' 128, 192 or 256 Bits.
            crypto.Key = pdb.GetBytes(cb:=(size \ 8)) ' 16, 24, or 32 or Bytes (128, 192 or 256 Bits).
            crypto.IV = pdb.GetBytes(cb:=16) ' 16 Bytes (128 Bits).
            crypto.Mode = mode
 
            Using ms As New MemoryStream()
 
                Using cs As New CryptoStream(ms, crypto.CreateDecryptor(), CryptoStreamMode.Write)
 
                    Dim cipherBytes As Byte() = Convert.FromBase64String(str)
                    cs.Write(cipherBytes, 0, cipherBytes.Length)
                    cs.Close()
 
                End Using
 
                Return Encoding.Unicode.GetString(ms.ToArray)
 
            End Using
 
        End Using
 
    End Function

If Not My.Settings.IsRandomized Then
  My.Settings.RandomValue = ' Generar valor aleatorio
  My.Settings.IsRandomized = True
End If
 
lbl.text = My.Settings.RandomValue.ToString