适用于VB.NET但不适用于C# - 字节转换

Question

所以我将一些代码从VB.NET迁移到C#,但是当它在C#中进行字节解析时失败了.

这是VB.NET代码可以工作:

Dim sModifiedAccountNumber_AsciiHex
Dim iByte As Byte = 0
Dim iIdx As Integer = 0
Dim strByte As String = String.Empty

sModifiedAccountNumber_AsciiHex = "FC13"
For iIdx = 1 To 3 Step 2

    iByte = CByte("&H" & Mid$(sModifiedAccountNumber_AsciiHex, iIdx, 2))
    If iByte >= 120 And iByte <= 127 Then
        iByte = iByte Or &H80
        strByte = Hex$(iByte)
        Do While Len(strByte) < 2
            strByte = "0" & strByte
        Loop
        Mid$(sModifiedAccountNumber_AsciiHex, iIdx, 2) = strByte
    End If

Next

C#版本:

string modAccountNumberAsciiHex = "FC13";
byte iByte;
string strByte = string.Empty;

for (int iIdx = 1; iIdx <= 3; iIdx += 2)
{
    iByte = byte.Parse(("&H" + modAccountNumberAsciiHex.Substring((iIdx - 1), 2)));
    if (iByte >= 120 && iByte <= 127)
    {
        iByte = iByte |= 0x80;
        strByte = BitConverter.ToString(new byte[] { iByte });
        while (strByte.Length < 2)
        {
            strByte = "0" + strByte;
        }

        // TODO: convert the line below to C#   
        // Mid$(sModifiedAccountNumber_AsciiHex, iIdx, 2) = strByte

    }
}

所以在C#中,我总是得到一个FormatException做时byte.Parse(后直for语句行)

关于C#应该是什么的任何想法？

此外 - TODO评论中的C#版本也将受到赞赏:-)

Answer 1

错误是在字符串的开头包含"&H",并且在byte.Parse没有指定的情况下使用NumberStyles.AllowHexSpecifier.Convert.ToByte尽管使用起来会更简单:

 byte x = Convert.ToByte(modAccountNumberAsciiHex.Substring(iIdx - 1, 2), 16)

另请注意,您的代码目前非常"基于1".这感觉就像移植VB.更惯用的C#将是:

for (int index = 0; index < 3; index += 2)
{
    byte x = Convert.ToByte(text.Substring(index, 2), 16);
    ...
}