[VB.NET]ASCII String與Hex String的互轉

ASCII要轉Hex，可透過ToString函式帶入"X2"，或是用Hex函式。因此ASCII String轉Hex String可寫成：
Public Function AsciiStringToHexString(ByVal asciiString As String) As String Dim ascii() As Byte = System.Text.Encoding.Default.GetBytes(asciiString) Dim count As Integer = ascii.Length Dim hexArray(count - 1) As String For idx As Integer = 0 To count - 1 hexArray(idx) = ascii(idx).ToString(“x2”) Next Return String.Join(" “, hexArray) End Function

而Hex要轉ASCII，可在前面帶入”&h"字串，轉成int後再轉為char。因此Hex String轉ASCII String可寫成:

  Public Function HexStringToAsciiString(ByVal hexString As String) As String 
    Dim array() As String = hexString.Split(New Char() {" "c}, StringSplitOptions.RemoveEmptyEntries) 
    For idx As Integer = 0 To array.Length - 1 
        array(idx) = Chr(CInt(String.Format("&h{0}", array(idx)))) 
    Next 
    Return String.Join(String.Empty, array) 
End Function

程式範例

範例介面

完整範例如下：

Public Class Form1

Public Function AsciiStringToHexString(ByVal asciiString As String) As String
    Dim ascii() As Byte = System.Text.Encoding.Default.GetBytes(asciiString)
    Dim count As Integer = ascii.Length
    Dim hexArray(count - 1) As String
    For idx As Integer = 0 To count - 1
        hexArray(idx) = ascii(idx).ToString("x2")
    Next
    Return String.Join(" ", hexArray)
End Function

Public Function HexStringToAsciiString(ByVal hexString As String) As String
    Dim array() As String = hexString.Split(New Char() {" "c}, StringSplitOptions.RemoveEmptyEntries)
    For idx As Integer = 0 To array.Length - 1
        array(idx) = Chr(CInt(String.Format("&h{0}", array(idx))))
    Next
    Return String.Join(String.Empty, array)
End Function

Private Sub tbxASCII_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tbxASCII.TextChanged
    If Me.ActiveControl Is sender Then
        tbxHex.Text = AsciiStringToHexString(tbxASCII.Text)
    End If
End Sub

Private Sub tbxHex_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tbxHex.TextChanged
    If Me.ActiveControl Is sender Then
        tbxASCII.Text = HexStringToAsciiString(tbxHex.Text)
    End If
End Sub

End Class