VB.Net/Network Remote/Web Request

Материал из VB Эксперт
Версия от 12:45, 26 мая 2010; Admin (обсуждение | вклад) (1 версия)
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Download Data from a URI

 
Imports System.IO
Imports System.Net
Imports System.Text
public class MainClass
   Shared Sub Main()
        Dim uri As New Uri("http://www.vbex.ru/index.htm")
        Dim request As WebRequest = WebRequest.Create(uri)
        Dim response As WebResponse = request.GetResponse()
        Dim stream As Stream = response.GetResponseStream()
        Dim reader As New StreamReader(stream)
        Dim data As String = reader.ReadToEnd()
        reader.Close()
        stream.Close()
        Console.WriteLine(data)
   End Sub
End Class


Get response and response stream from WebRequest

  
Imports System.Net
Imports System.IO
Public Class MainClass
    Public Shared Sub Main()
        Dim PageRequest As HttpWebRequest = WebRequest.Create("www.google.ru")
        Dim PageResponse As WebResponse = PageRequest.GetResponse()
        Dim PageReader As New StreamReader(PageResponse.GetResponseStream())
        Dim PageString As String = PageReader.ReadToEnd()
        PageReader.Close()
        System.Console.WriteLine(PageString)
    End Sub
End Class


Google Client

  
Imports System.IO
Imports System.Net
Imports System.Web
Imports System.Collections.Generic
Public Class GoogleClient
    Public Function Define(ByVal word As String) As String()
        Dim req As HttpWebRequest = Nothing
        Dim resp As HttpWebResponse
        Dim query As String
        Dim result As New List(Of String)
        query = "http://www.google.ru/search?q=define%3A" & HttpUtility.UrlEncode(word)
        Try
            req = DirectCast(WebRequest.Create(query), HttpWebRequest)
            With req
                .Method = "GET"
                resp = req.GetResponse
                If resp.StatusCode = HttpStatusCode.OK Then
                    ParseResponse(resp.GetResponseStream, result)
                Else
                    System.Console.WriteLine("Error calling definition service")
                End If
            End With
        Catch ex As Exception
            System.Console.WriteLine("Error getting definitions")
        End Try
        Return result.ToArray()
    End Function
    Private Sub ParseResponse(ByVal input As System.IO.Stream, ByRef output As List(Of String))
        Dim reader As New StreamReader(input)
        Dim work As String = reader.ReadToEnd
        System.Console.WriteLine(work) 
    End Sub
End Class


Is Connection Available

  
Public Class MainClass
    Public Shared Sub Main()
        System.Console.WriteLine(IsConnectionAvailable())
    End Sub
    Public Shared Function IsConnectionAvailable() As Boolean
        Dim objUrl As New System.Uri("http://www.yoursite.ru/")
        Dim objWebReq As System.Net.WebRequest
        objWebReq = System.Net.WebRequest.Create(objUrl)
        Dim objResp As System.Net.WebResponse
        Try
            objResp = objWebReq.GetResponse
            objResp.Close()
            objWebReq = Nothing
            Return True
        Catch ex As Exception
            Return False
        End Try
    End Function
End Class


Web Request and Response: type and content type, length

 
Imports System.IO
Imports System.Net
Imports System.Text
public class MainClass
   Shared Sub Main()
        Dim uri As New Uri("http://www.vbex.ru/index.htm")
        Dim request As WebRequest = WebRequest.Create(uri)
        Dim response As WebResponse = request.GetResponse()
        Console.WriteLine("Request type: " & request.GetType().ToString() )
        Console.WriteLine("Response type: " & response.GetType().ToString() )
        Console.WriteLine("Content length: " & response.ContentLength & " bytes" )
        Console.WriteLine("Content type: " & response.ContentType )
   End Sub
End Class