Option Explicit On
Option Strict On
Imports System.Text
''' --------------------------------------------------------------------------------
''' Project: RoundShapeLib
''' Class: CharInitializer
'''
''' Easy way to provide Char variable initialisation to your programs
''' This class is most efficient if your programs uses many char operations in the ASCII encoding
'''
'''
''' Author: Adam Ward
''' Date: 15 March 2005
'''
''' --------------------------------------------------------------------------------
Public Class CharInitializer
#Region "Member Data"
Private Shared _buffer() As Char = Nothing
Private Shared _enc As ASCIIEncoding = Nothing
#End Region
#Region "Public"
''' --------------------------------------------------------------------------------
''' Class.Method: CharInitializer.Chr
'''
''' Used mainly to initialise (or assign values to) char variables.
''' This is a framework compliant version of the old VB6 Chr$() function
'''
'''
''' The ASCII character code of the required char.
''' Value Type: (System.Byte)
'''
''' (System.Char)
'''
'''
''' --------------------------------------------------------------------------------
Public Shared Function Chr(ByVal index As Byte) As Char
If _buffer Is Nothing Then InitBuffer()
Return _buffer(index)
End Function
''' --------------------------------------------------------------------------------
''' Class.Method: CharInitializer.Chr
'''
''' Used mainly to initialise (or assign values to) char variables.
''' This is a framework compliant version of the old VB6 Chr$() function
'''
'''
''' The ASCII character code of the required char.
''' Value Type: (System.Int16)
'''
'''
''' Thrown when index is not in the range 0 to 255.
'''
''' (System.Char)
'''
'''
''' --------------------------------------------------------------------------------
Public Shared Function Chr(ByVal index As Short) As Char
If index < 0 Or index > Byte.MaxValue Then Throw New IndexOutOfRangeException
If _buffer Is Nothing Then InitBuffer()
Return _buffer(index)
End Function
''' --------------------------------------------------------------------------------
''' Class.Method: CharInitializer.Chr
'''
''' Used mainly to initialise (or assign values to) char variables.
''' This is a framework compliant version of the old VB6 Chr$() function
'''
'''
''' The ASCII character code of the required char.
''' Value Type: (System.Int32)
'''
'''
''' Thrown when index is not in the range 0 to 255.
'''
''' (System.Char)
'''
'''
''' --------------------------------------------------------------------------------
Public Shared Function Chr(ByVal index As Integer) As Char
If index < 0 Or index > Byte.MaxValue Then Throw New IndexOutOfRangeException
If _buffer Is Nothing Then InitBuffer()
Return _buffer(index)
End Function
''' --------------------------------------------------------------------------------
''' Class.Method: CharInitializer.Asc
'''
''' This is a framework compliant version of the old VB6 Asc() function
'''
'''
''' The char in question.
''' Value Type: (System.Char)
'''
''' (System.Byte)
'''
'''
''' --------------------------------------------------------------------------------
Public Shared Function Asc(ByVal character As Char) As Byte
If _buffer Is Nothing Then InitBuffer()
Return _enc.GetBytes(character)(0)
End Function
#End Region
Private Shared Sub InitBuffer()
'fills the _buffer with ascending char values, for example _buffer(65) contains "A"
Dim temp As Byte() = New Byte(255) {}
For i As Integer = 0 To 255
temp(i) = CType(i, Byte)
Next i
_enc = New ASCIIEncoding
_buffer = _enc.GetChars(temp)
End Sub
End Class