Conversion between IP address point notation and decimal notation

'

' Convert IP address point-to-point to decimal.

'

Public   Shared   Function dot2longip () Function Dot2longip ( Byval Dotip As   String ) As   Long

' Use regular expressions to check IP addresses

Dim Subip As   String () =   Split (Dotip, " . " )

' IP address = W. x. y. Z

' IP number = 16777216 * w + 65536 * x + 256 * Y + z



Dot2longip =   16777216   *   Clng (Subip ( 0 )) +   65536   *   Clng (Subip ( 1 )) +   256   *   Clng (Subip ( 2 )) +   Clng (Subip ( 3 ))


End Function


Public   Shared   Function longip2dot () Function Longip2dot ( Byval Longip As   Long ) As   String

' IP address = W. x. y. Z

' IP number = 16777216 * w + 65536 * x + 256 * Y + z



' W = int (IP number/16777216) % 256

' X = int (IP number/65536) % 256

' Y = int (IP number/256) % 256

' Z = int (IP number) % 256



Dim Dotip As   String

Dim Subip As   Integer


Subip =   CINT (Fix (longip /   16777216) ) MoD   256

Dotip =   CSTR (Subip) +   " ."



Subip =   CINT (Fix (longip /   65536) ) MoD   256

Dotip + =   CSTR (Subip) +   " ."



Subip =   CINT (Fix (longip /   256) ) MoD   256

Dotip + =   CSTR (Subip) +   " ."



Subip =   CINT (Fix (longip MoD   256) )

Dotip + =   CSTR (Subip)


Return Dotip

End Function

In addition, ninputer: The method is indeed good, and the efficiency must be higher than the previous calculation method.
< Structlayout (layoutkind. Explicit ) > _

Public   Structure ipconvert Structure Ipconvert

< Fieldoffset ( 0 ) >   Public Longip As   Long  

< Fieldoffset ( 0 ) >   Public Dotip0 As   Byte  

< Fieldoffset ( 1 ) >   Public Dotip1 As   Byte  

< Fieldoffset ( 2 ) >   Public Dotip2 As   Byte  

< Fieldoffset ( 3 ) >   Public Dotip3 As   Byte  

End Structure  

Note that the namespace system. runtime. interopservices must be introduced, and the longip type is indeed long, not integer.