用Socket类构建网页下载器-.NET教程,评论及其它

private sub btnhtml_click(byval sender as system.object, byval e as system.eventargs) handles btnhtml.click
　　dim serverip as ipaddress = dns.resolve(“http://www.tuenhai.com“).addresslist(0)
　　 default web server port = 80
　　dim port as string = “80”
　　dim serverhost as new ipendpoint(serverip, int32.parse(port))

　　dim clientsocket as new socket(addressfamily.internetwork, sockettype.stream, protocoltype.tcp)

　　try
　　　　clientsocket.connect(serverhost)

　　　　if clientsocket.connected = false then
　　　　　　msgbox(“connect error.”, msgboxstyle.critical, “http”)
　　　　　　exit sub
　　　　end if

　　　　dim httpreq as string = “get / http/1.0” & controlchars.crlf & controlchars.crlf

　　　　clientsocket.send(ascii.getbytes(httpreq))

　　　　dim buffer(1024) as byte
　　　　dim bytecount as int16 = clientsocket.receive(buffer, buffer.length, 0)

　　　　txthtml.text = ascii.getstring(buffer, 0, bytecount)

　　　　do while bytecount > 0
　　　　　　bytecount = clientsocket.receive(buffer, buffer.length, 0)
　　　　　　txthtml.text = txthtml.text & ascii.getstring(buffer, 0, bytecount)
　　　　loop
　　catch ex as exception
　　 　msgbox(ex.stacktrace.tostring(), msgboxstyle.critical, “exception”)
　　end try
end sub