Declare Function inet_addr Lib "ws2_32.dll" (cp As BytePtr) As Long
Declare Function sendto Lib "wsock32.dll" (ByVal s As Long, buf As String, ByVal lngLen As Long, ByVal flags As Long,ByRef sTo As sockaddr_in, ByVal tolen As Long) As Long

Sub MainWnd_Destroy()
udp_DestroyObjects()
PostQuitMessage(0)
End Sub

Sub MainWnd_CommandButton1_Click()

'IPアドレス、ポート番号、ソケット
Dim destSocket As Dword

'sockaddr_in 構造体
Dim destSockAddr As SOCKADDR_IN

'各種パラメータ
Dim toSendText[256] As Byte
lstrcpy(toSendText,"Test")

'************************************************************
'* Windows 独自の設定 *
Dim wsaData As WSADATA
WSAStartup(MAKEWORD(2,0), wsaData)

'* 相手先アドレスの入力 *
'* sockaddr_in 構造体のセット *
ZeroMemory( VarPtr(destSockAddr), Len(destSockAddr))
destSockAddr.sin_family = AF_INET
destSockAddr.sin_port = htons(1234)
destSockAddr.sin_addr = inet_addr("127.0.0.1")

'* ソケット生成 *
destSocket = socket(AF_INET, SOCK_DGRAM, 0)

'* パケット送出 *
sendto ( destSocket, toSendText,lstrlen(toSendText)+1, 0, destSockAddr , len(destSockAddr.sin_addr ))
Sleep(5000)

MessageBox( 0,Str$(GetLastError()), "sendto", MB_OK)

'* Windows 独自の設定 *
closesocket(destSocket)
WSACleanup()

End Sub

Declare Function inet_addr Lib "ws2_32.dll" (cp As BytePtr) As Long
Declare Function sendto Lib "wsock32.dll" (ByVal s As Long, buf As *Byte, ByVal lngLen As Long, ByVal flags As Long,ByRef sTo As sockaddr_in, ByVal tolen As Long) As Long

Sub MainWnd_Destroy()
udp_DestroyObjects()
PostQuitMessage(0)
End Sub

Sub MainWnd_CommandButton1_Click()

'IPアドレス、ポート番号、ソケット
Dim destSocket As Dword

'sockaddr_in 構造体
Dim destSockAddr As SOCKADDR_IN

'各種パラメータ
Dim toSendText[256] As Byte
lstrcpy(toSendText,"Test")

'************************************************************
'* Windows 独自の設定 *
Dim wsaData As WSADATA
WSAStartup(MAKEWORD(2,0), wsaData)

'* 相手先アドレスの入力 *
'* sockaddr_in 構造体のセット *
ZeroMemory( VarPtr(destSockAddr), Len(destSockAddr))
destSockAddr.sin_port = htons(1234)
destSockAddr.sin_family = AF_INET
destSockAddr.sin_addr = inet_addr("127.0.0.1")

'* ソケット生成 *
destSocket = socket(AF_INET, SOCK_DGRAM, 0)
'* パケット送出 *
sendto ( destSocket, toSendText,lstrlen(toSendText)+1, 0, destSockAddr , len(destSockAddr ))
MessageBox( 0,Str$(GetLastError()), "sendto", MB_OK)

'* Windows 独自の設定 *
closesocket(destSocket)
WSACleanup()

End Sub