不寻常的整数编码为字节 - 这是什么方案?
Unusual Integer encoding to bytes - what scheme is this?
使用什么整数编码方案来实现以下内容,我们如何在.Net中做到这一点:
127 = 7F
128 = 8001
255 = FF01
256 = 8002
500 = F403
不太确定它有正式名称,它是一个 7 位编码。它是一种可变长度编码,如果后面跟着另一个字节,则设置一个字节的高位。字节顺序是小端。
.NET Framework uses it,Write7BitEncodedInt() 方法。由 BinaryWriter.WriteString() 方法使用,它节省了 space,因为大多数实用的字符串少于 128 个字符。
所以 F403 => 03F4 => |0000011|1110100| => |00000001|11110100| => 0x1F4 == 500
已解决。我希望这对其他人有帮助。
Dim o = {127, 128, 255, 256, 500}
For Each i As Integer In o
Console.WriteLine("{0} = {1}", i, Write(i))
Next
Function Write(value As Short) As String
Dim a = New List(Of Byte)
' Write out an int 7 bits at a time. The high bit of the byte,
' when on, tells reader to continue reading more bytes.
Dim v = CShort(value)
' support negative numbers
While v >= &H80
a.Add(CByte((v And &HFF) Or &H80))
v >>= 7
End While
a.Add(CByte((v And &HFF)))
Return B2H(a.ToArray)
End Function
Function B2H(b() As Byte) As String
Return BitConverter.ToString(b).Replace("-", "")
End Function
结果:
127 = 7F
128 = 8001
255 = FF01
256 = 8002
500 = F403
使用什么整数编码方案来实现以下内容,我们如何在.Net中做到这一点:
127 = 7F
128 = 8001
255 = FF01
256 = 8002
500 = F403
不太确定它有正式名称,它是一个 7 位编码。它是一种可变长度编码,如果后面跟着另一个字节,则设置一个字节的高位。字节顺序是小端。
.NET Framework uses it,Write7BitEncodedInt() 方法。由 BinaryWriter.WriteString() 方法使用,它节省了 space,因为大多数实用的字符串少于 128 个字符。
所以 F403 => 03F4 => |0000011|1110100| => |00000001|11110100| => 0x1F4 == 500
已解决。我希望这对其他人有帮助。
Dim o = {127, 128, 255, 256, 500}
For Each i As Integer In o
Console.WriteLine("{0} = {1}", i, Write(i))
Next
Function Write(value As Short) As String
Dim a = New List(Of Byte)
' Write out an int 7 bits at a time. The high bit of the byte,
' when on, tells reader to continue reading more bytes.
Dim v = CShort(value)
' support negative numbers
While v >= &H80
a.Add(CByte((v And &HFF) Or &H80))
v >>= 7
End While
a.Add(CByte((v And &HFF)))
Return B2H(a.ToArray)
End Function
Function B2H(b() As Byte) As String
Return BitConverter.ToString(b).Replace("-", "")
End Function
结果:
127 = 7F
128 = 8001
255 = FF01
256 = 8002
500 = F403