本节将用一个简单的例子来说明文本编码：

窗体设计如下：

comboBox中的数据：

请引用 System.Text

Imports System.Text

当按下“生成”按钮时的代码：

    Private Sub btnChange_Click(sender As Object,e As EventArgs) Handles btnChange.Click
        Dim enc As Encoding
        Select Case cbEncode.Text
            Case "ASCII"
                enc = Encoding.ASCII
            Case "Unicode"
                enc = Encoding.Unicode
            Case "UTF32"
                enc = Encoding.UTF32
            Case "UTF7"
                enc = Encoding.UTF7
            Case "UTF8"
                enc = Encoding.UTF8
            Case "GB2312"
                enc = Encoding.GetEncoding("gb2312")
            Case "big5"
                enc = Encoding.GetEncoding("big5")
        End Select


        Dim byteSource() As Byte = enc.GetBytes(txtSource.Text)

        Dim strEnc As String = ""
        For i As Integer = 0 To byteSource.Length - 1
            strEnc &= Convert.ToString(byteSource(i),16).ToUpper & " "
        Next
        txtDest.Text &= "编码方式：" & enc.EncodingName & "编码结果：" & strEnc & vbCrLf
    End Sub

运行结果：

可以看到ASCII不支持繁体 "無" 字，返回的是3F（十进制：63），查找ASCII表，可知，返回的是“?”。

同样，Big5不支持简体的“无”字，返回的也是3F。

简单的测试将字节数组编码成字符：

    Private Sub Button1_Click(sender As Object,e As EventArgs) Handles Button1.Click
        Dim byteSource() As Byte
        ReDim byteSource(1)
        '無
        byteSource(0) = 181  '=>B5
        byteSource(1) = 76   '=>4C

        Dim enc As Encoding
        enc = Encoding.GetEncoding("big5")
        Dim strDest As String
        strDest = enc.GetString(byteSource)
        txtSource.Text = strDest
    End Sub

由于.net平台下C#和vb.NET很相似，本文也可以为C#爱好者提供参考。

学习更多vb.net知识，请参看 vb.net 教程 目录