Question

希望有人可以帮助我。

我有以下代码返回我从这里获得的IP地址：

https://www.novell.com/communities/coolsolutions/cool_tools/reading-ldap-networkaddress-attribute-server-or-user-object/

在C＃（下面的代码）中完美运行

LdapAttribute serverNetAddr = entry.getAttribute("networkaddress");

// loop through the multivalued networkaddress field
foreach (sbyte[] addrBytes in serverNetAddr.ByteValueArray)
{

    // get the first character in the line which indicates type
    char type = (char)addrBytes[0];

    if (type == '9')
    { // only interested in TCP address
        string serverTCPAddr = "";
        for (int i = (addrBytes.Length - 4); i < addrBytes.Length; i++)
        { // last four bytes are the ip address
            byte b = unchecked((byte)addrBytes[i]); // convert sbyte to byte
            serverTCPAddr = serverTCPAddr + b; // append value to string
            if (i > 0 && i < (addrBytes.Length - 1))
                serverTCPAddr = serverTCPAddr + "."; // brute force the dots
            textBox1.Text = serverTCPAddr;
        }

    }

}

当我尝试使用VB.net中的代码时（参见下面的代码）它只能工作到“For i As Integer = (addrBytes.Length - 4) To addrBytes.Length – 1”当代码变为“Dim b As Byte = unchecked(CByte(addrBytes(i)))”然后我收到以下错误消息：

＆＃34; System.OverflowException：算术运算导致了。溢出＆＃34;

    Dim serverNetAddr As LdapAttribute = entry.getAttribute("networkaddress")



    ' loop through the multivalued networkaddress field
    Dim addrBytes() As System.SByte
    For Each addrBytes In serverNetAddr.ByteValueArray

        ' get the first character in the line which indicates type
        Dim type As Char = ChrW(addrBytes(0))

        If type = "9"c Then
            ' only interested in TCP address
            Dim serverTCPAddr As String = ""
            Dim i As Integer
            For i = (addrBytes.Length - 4) To addrBytes.Length - 1
                ' last four bytes are the ip address
                '  Dim b As Byte = CType(addrBytes(i), Byte)  ' convert sbyte to byte



                Dim b As Byte = unchecked(CByte(addrBytes(i)))

                ' Dim b As SByte = unchecked(CType(addrBytes(i), Byte))  ' convert sbyte to byte
                serverTCPAddr = serverTCPAddr + b ' append value to string
                If i > 0 And i < (addrBytes.Length - 1) Then
                    serverTCPAddr = serverTCPAddr + "." ' brute force the dots
                End If
                TextBox6.Text = serverTCPAddr
            Next

        End If

    Next

End If

下一步

我尝试过“Dim b As Byte = CByte(addrBytes(i))”和“Dim b As SByte = unchecked(CType(addrBytes(i), Byte))”＆＃39; convert sbyte to byte 无济于事，它继续在Dim b As Byte部分崩溃。

任何人都可以告诉我为什么它在C＃中运行而不是VB.net，可能还有一种解决方法吗？

谢谢你，问候， Zain Peters

Answer 1

名为Viorel_的用户在此处解决了问题：https://social.msdn.microsoft.com/Forums/vstudio/en-US/5e68f6c5-0e60-4c1f-bcd4-c7aad97e83fb/vbnet-sbyte-to-byte-poroblem?forum=vbgeneral

Dim sb As SByte

Dim b As Byte

sb = -2

b = CByte(sb And &HFF) ' result: 254

谢谢大家！

VB.net Sbyte to Byte poroblem

1 个答案: