GET访问：
dim httpClient as new WebClient() httpClient.strUrl="http://www.baidu/com?wd=hello" httpClient.Proc() Msgbox(httpClient.RespHtml)
POST访问：
dim httpClient as new WebClient() httpClient.strUrl="http://www.baidu/com?wd=hello" httpClient.strTextField="user=zhans&psd=1332" httpClient.Proc(true)'true表示要记录cookie Msgbox(httpClient.RespHtml)
Imports System Imports System.Text Imports System.IO Imports System.Net Imports System.Net.Sockets Imports Microsoft.VisualBasic ''' <summary> ''' 实现向web发送和接收数据的类 ''' </summary> ''' <remarks></remarks> Public Class WebClient Const BOUNDARY As String = "--HEDAODE--" Const SEND_BUFFER_SIZE As Integer = 8000 Const RECEIVE_BUFFER_SIZE As Integer = 15000 Dim _strUrl, _strTextField, _strFileField As String Dim method, contentType, host, path, _headerText, _respHtml, _referer, _cookie As String Public Encode As Encoding = Encoding.Default Dim r As RegularExpressions.Regex Dim m As RegularExpressions.Match Dim PostDataList()(), header() As Byte Dim _start As Boolean = True Dim _SendProgress, _ReceiveProgress, _SendContentLength, _ReceiveContentLength, startIndex As Integer ''' <summary> ''' 请求的url地址 ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> Property strUrl() As String Get Return _strUrl End Get Set(ByVal value As String) If value <> "" Then m = r.Match(value, "https*://([^/]+)(/(.+))?") If m.Success Then host = m.Groups(1).Value path = "/" + m.Groups(3).Value _strUrl = value Else MsgBox("URL不合法!") End If End If End Set End Property ''' <summary> ''' 要发送的文本域 ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> Property strTextField() As String Get Return _strTextField End Get Set(ByVal value As String) If value <> "" Then m = r.Match(value, "(\w+=[^&]+)|((\w+=[^&]+&)+)") If m.Success Then _strTextField = value Else MsgBox("数据有误:" & value) End If End If End Set End Property ''' <summary> ''' 要发送的文件域 ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> Property strFileField() As String Get Return _strFileField End Get Set(ByVal value As String) If value <> "" Then m = r.Match(value, "(\w+=[^&]+)|((\w+=[^&]+&)+)") If m.Success Then _strFileField = value Else MsgBox("数据有误:" & value) End If End If End Set End Property ''' <summary> ''' 获取或设置Cookie ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks>用来跟踪用户身份</remarks> Property Cookie() As String Get Return _cookie End Get Set(ByVal value As String) _cookie = value End Set End Property ''' <summary> ''' 获取或设置Referer ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks>模拟上一次访问地址</remarks> Property Referer() As String Get Return _referer End Get Set(ByVal value As String) _referer = value End Set End Property ''' <summary> ''' 获取http响应头文本 ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> ReadOnly Property headerText() As String Get Return _headerText End Get End Property ''' <summary> ''' 获取服务器返回的文本 ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> Property RespHtml() As String Get Return _respHtml End Get Set(ByVal value As String) _respHtml = value End Set End Property ''' <summary> ''' 获取发送实体大小 ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> ReadOnly Property SendContentLength() As Integer Get Return _SendContentLength End Get End Property ''' <summary> ''' 获取接收实体大小 ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> ReadOnly Property ReceiveContentLength() As Integer Get Return _ReceiveContentLength End Get End Property ''' <summary> ''' 获取数据发送进度 ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> ReadOnly Property SendProgress() As Integer Get Return _SendProgress End Get End Property ''' <summary> ''' 获取数据接收进度 ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> ReadOnly Property ReceiveProgress() As Integer Get Return _ReceiveProgress End Get End Property ''' <summary> ''' 设置是否立即中断发送和接收数据 ''' </summary> ''' <value></value> ''' <returns></returns> ''' <remarks></remarks> Property Start() As Boolean Get Return _start End Get Set(ByVal value As Boolean) _start = value End Set End Property ''' <summary> ''' 建立socket连接 ''' </summary> ''' <param name="server"></param> ''' <param name="port"></param> ''' <returns></returns> ''' <remarks></remarks> Private Function ConnectSocket(ByVal server As String, ByVal port As Integer) As Sockets.Socket Dim s As Sockets.Socket = Nothing Dim hostEntry As IPHostEntry = Nothing ' Get host related information. Try hostEntry = Dns.GetHostEntry(server) ' Loop through the AddressList to obtain the supported AddressFamily. This is to avoid ' an exception that occurs when the host host IP Address is not compatible with the address family ' (typical in the IPv6 case). Dim address As IPAddress For Each address In hostEntry.AddressList Dim endPoint As New IPEndPoint(address, port) Dim tempSocket As New Sockets.Socket(endPoint.AddressFamily, SocketType.Stream, ProtocolType.Tcp) tempSocket.Connect(endPoint) If tempSocket.Connected Then s = tempSocket Exit For End If Next address Return s Catch ex As Exception Return Nothing End Try End Function ''' <summary> ''' 发送并接收数据 ''' </summary> ''' <returns></returns> ''' <remarks></remarks> Private Function SocketSendReceive(Optional ByVal progress As Boolean = False) As Byte() _SendProgress = 0 _ReceiveProgress = 0 Dim s As Sockets.Socket = ConnectSocket(host, 80) If s Is Nothing Then Return Encode.GetBytes("无法解析主机名称") End If Dim i, count As Integer Dim receivedByte() As Byte '创建请求数据 CreateRequestData() Try '发送数据**************************************** s.SendTimeout = 5000 s.Send(header) '发送请求头 '如果有数据要发送就继续发送 If Me._SendContentLength > 0 Then For i = 0 To PostDataList.Length - 1 If Not Start Then s.Close() Return Encode.GetBytes("中断") End If s.Send(PostDataList(i)) '将缓冲区的数据发送出去 _SendProgress += PostDataList(i).Length Next s.Shutdown(SocketShutdown.Send) '停止发送数据 End If '接收数据***************************************** Do If Not Start Then s.Close() Return Encode.GetBytes("中断") End If Dim receiveBuffer(RECEIVE_BUFFER_SIZE) As Byte count = s.Receive(receiveBuffer) ReDim Preserve receiveBuffer(count - 1) receivedByte = UniteArr(receivedByte, receiveBuffer) _ReceiveProgress += count Loop While count > 0 s.Close() Me._strTextField = "" Me._strFileField = "" Return GetResponseByte(receivedByte) Catch ex As Exception Return Encode.GetBytes(ex.Message) End Try End Function ''' <summary> ''' 分析服务器返回的字节流，去掉响应头，返回实体部分 ''' </summary> ''' <param name="receivedByte"></param> ''' <returns></returns> ''' <remarks></remarks> Function GetResponseByte(ByRef receivedByte() As Byte) As Byte() Dim tempByte() As Byte If Not receivedByte Is Nothing Then If receivedByte.Length <= 5000 Then GetHeaderInfo(receivedByte) Else Dim headByte(5000) As Byte Array.Copy(receivedByte, headByte, 5000) GetHeaderInfo(headByte) End If If Me._ReceiveContentLength > receivedByte.Length - startIndex Then ReDim tempByte(receivedByte.Length - startIndex - 1) Me._ReceiveContentLength = tempByte.Length Array.Copy(receivedByte, startIndex, tempByte, 0, tempByte.Length) Else ReDim tempByte(Me._ReceiveContentLength - 1) Array.Copy(receivedByte, startIndex, tempByte, 0, Me._ReceiveContentLength) End If Return tempByte Else Return Encode.GetBytes("没有数据返回") End If End Function ''' <summary> ''' 分析获取响应头，获取实体大小 ''' </summary> ''' <param name="receiveBuffer"></param> ''' <remarks></remarks> Private Sub GetHeaderInfo(ByVal receiveBuffer() As Byte) Dim text As String = Encode.GetChars(receiveBuffer) m = r.Match(text, "(.+" + vbCrLf + ")+" + vbCrLf + "((?<len>[a-fA-F0-9]{1,20}) {0,20}" + vbCrLf + ")?") If m.Success Then If m.Groups("len").Value <> "" Then '某些服务器在响应头里 Me._ReceiveContentLength = "&H" + m.Groups("len").Value Else Me._ReceiveContentLength = 500000 '如果响应头中没有实体大小，就取前500K，但这种几率很小 End If startIndex = Encode.GetBytes((m.Value)).Length '实体开始的字节位置 _headerText = m.Value '响应头 End If '获取实体大小 m = r.Match(text, "Content-Length:(?<len>.+)") If m.Success Then Me._ReceiveContentLength = Trim(m.Groups("len").Value) End If End Sub ''' <summary> ''' 向服务器请求数据并返回响应文本 ''' </summary> ''' <param name="SetCookie">如果要保存cookie则为true</param> ''' <returns></returns> ''' <remarks></remarks> Function Proc(Optional ByVal SetCookie As Boolean = False) As String _respHtml = Encode.GetChars(SocketSendReceive) If SetCookie And _headerText <> "" Then '从响应头中获取cookie m = r.Match(_headerText, "Set-Cookie:([^;]+)") Do While m.Success Cookie += m.Groups(1).Value + ";" m = m.NextMatch Loop Cookie = Trim(Cookie) End If Return _respHtml End Function ''' <summary> ''' 上传文件 ''' </summary> ''' <returns></returns> ''' <remarks></remarks> Function UploadFile() As String _respHtml = Encode.GetChars(SocketSendReceive) Return _respHtml End Function ''' <summary> ''' 下载文件 ''' </summary> ''' <param name="SavePath">文件保存路径，含文件名</param> ''' <remarks></remarks> Sub DownLoadFile(ByVal SavePath As String) Dim receivedData() As Byte = SocketSendReceive() If Start Then Dim fs As New FileStream(SavePath, FileMode.Create) fs.Write(receivedData, 0, receivedData.Length) fs.Close() fs = Nothing End If End Sub ''' <summary> ''' 创建http请求数据包 ''' </summary> ''' <remarks></remarks> Private Sub CreateRequestData() Dim PostData() As Byte If strTextField = "" And strFileField = "" Then '不发送任何数据 Me.method = "GET" Me._SendContentLength = 0 ElseIf strTextField <> "" And strFileField <> "" Then '发送文本和文件数据 Dim strText As String = "" m = r.Match(_strTextField, "(\w+)=([^&]+)") Do While m.Success strText += "--" + BOUNDARY + vbCrLf strText += "Content-Disposition: form-data; name=""" + m.Groups(1).Value + """" + vbCrLf + vbCrLf + m.Groups(2).Value + vbCrLf m = m.NextMatch Loop PostData = UniteArr(Encode.GetBytes(strText), GetFileByte(_strFileField)) Me.method = "POST" Me.contentType = "multipart/form-data; boundary=" + BOUNDARY Me._SendContentLength = PostData.Length GetPostDataList(PostData) ElseIf strTextField <> "" Then '只发送文本数据 PostData = Encode.GetBytes(strTextField) Me.method = "POST" Me.contentType = "application/x-www-form-urlencoded" Me._SendContentLength = PostData.Length GetPostDataList(PostData) ElseIf strFileField <> "" Then '只发送文件数据 PostData = GetFileByte(strFileField) Me.method = "POST" Me.contentType = "multipart/form-data; boundary=" + BOUNDARY Me._SendContentLength = PostData.Length GetPostDataList(PostData) End If header = GetHeader() End Sub ''' <summary> ''' 获取http请求头数据 ''' </summary> ''' <returns></returns> ''' <remarks></remarks> Private Function GetHeader() As Byte() Dim strHeader As String strHeader = method + " " + path + " HTTP/1.1" + vbCrLf strHeader += "Accept: */*" + vbCrLf strHeader += "Accept-Language: zh-cn" + vbCrLf strHeader += "User-Agent: Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)" + vbCrLf strHeader += "Host: " + host + vbCrLf If Referer <> "" Then strHeader += "Referer: " + Referer + vbCrLf End If Referer = "" If Me._SendContentLength > 0 Then strHeader += "Content-Type: " + contentType + vbCrLf strHeader += "Content-Length: " & Me._SendContentLength & vbCrLf 'strHeader += "Expect:100-continue" + vbCrLf strHeader += "Connection: Keep-Alive" + vbCrLf Else strHeader += "Connection: Close" + vbCrLf End If If Cookie <> "" Then strHeader += "Cookie: " + _cookie + vbCrLf strHeader += vbCrLf Return Encode.GetBytes(strHeader) End Function ''' <summary> ''' 获取发送文件数据 ''' </summary> ''' <param name="strFileField">文件域名称及文件路径</param> ''' <returns></returns> ''' <remarks></remarks> Private Function GetFileByte(ByVal strFileField As String) As Byte() Dim postByte() As Byte Dim filePath As String m = r.Match(strFileField, "(\w+)=([^&]+)") Do While m.Success filePath = m.Groups(2).Value If File.Exists(filePath) Then strFileField = "--" + BOUNDARY + vbCrLf strFileField += "Content-Disposition: form-data; name=""" + m.Groups(1).Value + """; filename=""" + filePath + """" + vbCrLf strFileField += "Content-Type: image/jpeg" + vbCrLf + vbCrLf postByte = UniteArr(postByte, Encode.GetBytes(strFileField)) Dim fs As New FileStream(filePath, FileMode.Open) Dim br As New BinaryReader(fs) postByte = UniteArr(postByte, br.ReadBytes(fs.Length)) br.Close() fs.Close() postByte = UniteArr(postByte, Encode.GetBytes(vbCrLf)) Else MsgBox("上传文件不存在！") End If m = m.NextMatch Loop postByte = UniteArr(postByte, Encode.GetBytes("--" + BOUNDARY + "--" + vbCrLf)) Return postByte End Function ''' <summary> ''' 将大数据包拆分成小包 ''' </summary> ''' <param name="postData">要拆分的数据包</param> ''' <remarks></remarks> Private Sub GetPostDataList(ByRef postData() As Byte) Dim blockCount, remnant, i, p As Integer blockCount = postData.Length \ SEND_BUFFER_SIZE '整块个数 remnant = postData.Length Mod SEND_BUFFER_SIZE '零头 Dim bufferList(blockCount + IIf(remnant > 0, 0, -1))() As Byte '复制整块 For i = 0 To blockCount - 1 ReDim bufferList(i)(SEND_BUFFER_SIZE - 1) System.Array.Copy(postData, p, bufferList(i), 0, SEND_BUFFER_SIZE) p += SEND_BUFFER_SIZE Next '复制零头 If remnant > 0 Then ReDim bufferList(i)(remnant - 1) System.Array.Copy(postData, p, bufferList(i), 0, remnant) End If PostDataList = bufferList End Sub ''' <summary> ''' 合并两个字节数组 ''' </summary> ''' <param name="byte1"></param> ''' <param name="byte2"></param> ''' <returns></returns> ''' <remarks></remarks> Function UniteArr(ByVal byte1() As Byte, ByVal byte2() As Byte) As Byte() Dim temp() As Byte If byte1 Is Nothing And byte2 Is Nothing Then MsgBox("两个数组不能同时为空！") Return Nothing ElseIf byte1 Is Nothing Then ReDim temp(byte2.Length - 1) Array.Copy(byte2, 0, temp, 0, byte2.Length) ElseIf byte2 Is Nothing Then ReDim temp(byte1.Length - 1) Array.Copy(byte1, 0, temp, 0, byte1.Length) Else ReDim temp(byte1.Length + byte2.Length - 1) Array.Copy(byte1, 0, temp, 0, byte1.Length) Array.Copy(byte2, 0, temp, byte1.Length, byte2.Length) End If Return temp End Function End Class