README.md
December 5, 2022 ยท View on GitHub
Description
The code sample given below demonstrates how to communicate with a news server using NNTP.
The sample is not a complete implementation of NNTP client, but rather a demonstratio of how to communicate with a NNTP server via System.Net.Sockets.TcpClient . For more details on NNTP communication please refer RFC0977.
More Info
| Submitted On | |
| By | Anoj Kumar |
| Level | Advanced |
| User Rating | 4.6 (23 globes from 5 users) |
| Compatibility | VB.NET, ASP.NET |
| Category | Miscellaneous |
| World | .Net (C#, VB.net) |
| Archive File |
Source Code
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Dynamically displaying messages from newsgroups using ASP.Net Summary The sample is not a complete implementation of NNTP client, but rather a demonstratio of how to communicate with a NNTP server via System.Net.Sockets.TcpClient . For more details on NNTP communication please refer RFC0977. Code <%@ Page Language="VB" Debug="true" %>
<%@ import Namespace="System.Net.Sockets" %>
<%@ import Namespace="System.IO" %>
<script runat="server">
Sub Page_Load(sender As Object, e As EventArgs)
Dim tcpClient As New System.Net.Sockets.TcpClient()
tcpClient.Connect("news.microsoft.com", 119)
Dim networkStream As NetworkStream = tcpClient.GetStream()
Dim responseArr() as string
Dim bytes(tcpClient.ReceiveBufferSize) As Byte
networkStream.Read(bytes, 0, CInt(tcpClient.ReceiveBufferSize))
' send GROUP command to get the staus and number of messages available
' the format returned will be
'211 104 10011 10125 microsoft.public.dotnet.framework.aspnet group selected
'(there are 104 articles on file, from 10011 to 10125)
Dim sendBytes As [Byte]() = Encoding.ASCII.GetBytes("GROUP " & _
DropDownList1.items(DropDownList1.selectedindex).value & ControlChars.CrLf)
networkStream.write(sendBytes,0,sendBytes.length)
bytes.clear(bytes,0,bytes.length)
networkStream.Read(bytes, 0, CInt(tcpClient.ReceiveBufferSize))
responseArr=split(Encoding.ASCII.GetString(bytes))
'we are interested in 3rd index as it contains the last number of message
Dim fetchFrom as long=ctype(responseArr(3),long)
fetchFrom =fetchFrom-6 ' subtract it from 10 as we r interested in latest 6 messages
Dim i as integer
for i=1 to 6
sendbytes=Encoding.ASCII.GetBytes("ARTICLE " & fetchFrom & ControlChars.CrLf )
networkStream.write(sendBytes,0,sendBytes.length)
bytes.clear(bytes,0,bytes.length)
networkStream.Read(bytes, 0, CInt(tcpClient.ReceiveBufferSize))
Dim Message as String
Dim Header as String
Dim Body as String
Dim curLine as String
Message=Encoding.ASCII.GetString(bytes)
if left(Message,3)="220" then ' if status is OK=220 then
Header=left(Message,instr(1,Message,ControlChars.CrLf & ControlChars.CrLf))' get the header
Body=mid(Message,instr(1,Message,ControlChars.CrLf & ControlChars.CrLf))' get the body part
Dim sr as new Stringreader(Header)
curLine=sr.readLine()
while not curLine is nothing
if instr(1,curLine,"From:")=1 or instr(1,curLine,"Sender:")=1 & _
or instr(1,curLine,"Date:")=1 or instr(1,curLine,"Message-ID:") then
AddToTable(curLine,true)
end if
curLine=sr.readLine()
end while
AddToTable(Body,false)
else
AddToTable("Failed to receive message (" & fetchfrom &")",true)
end if
fetchfrom += 1
next
tcpClient.Close()
End Sub
Sub AddToTable(ss as String,Header as Boolean)
Dim tr as new TableRow()
Dim td as new TableCell()
me.table1.rows.add(tr)
tr.cells.add(td)
if header then
td.BackColor=System.Drawing.Color.Silver
td.text=ss
else
td.text="<PRE>" & Server.HtmlEncode(ss) & "</PRE>"
end if
End SuB
</script>
<html>
<head>
</head>
<body>
<form runat="server">
<p>
<table style="WIDTH: 508px; HEIGHT: 28px" border="0">
<tbody>
<tr>
<td>
Select a Newsgroup</td>
<td>
<asp:DropDownList id="DropDownList1" runat="server" Width="274px">
<asp:ListItem Value="microsoft.public.dotnet.framework.aspnet">
microsoft.public.dotnet.framework.aspnet</asp:ListItem>
<asp:ListItem Value="microsoft.public.dotnet.languages.vb">
microsoft.public.dotnet.languages.vb</asp:ListItem>
<asp:ListItem Value="microsoft.public.xml">microsoft.public.xml</asp:ListItem>
</asp:DropDownList>
<input type="submit" value="Submit" /></td>
</tr>
</tbody>
</table>
</p>
<p>
<br />
<asp:Label id="lab1" runat="server"></asp:Label>
<br />
<asp:Table id="Table1" runat="server" BorderColor="Gray" BorderWidth="1px" CellSpacing="0"
CellPadding="3" BorderStyle="Solid" GridLines="Both"></asp:Table>
</p>
</form>
</body>
</html>
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