Question

我有一个可以在浏览器中正常运行的ASP.NET MVC应用程序。

我正在使用以下代码来编写检索到的页面的html到文件。（这是用于PDF转换组件）

但是这段代码不断出错，但不会在浏览器中出错。

我有时会因为500错误而出现超时错误。

Public Function GetPage(ByVal url As String, ByVal filename As String) As Boolean

        Dim request As HttpWebRequest
        Dim username As String
        Dim password As String
        Dim docid As String
        Dim poststring As String
        Dim bytedata() As Byte
        Dim requestStream As Stream

        Try
            username = "pdfuser"
            password = "pdfuser"
            docid = "docid=inv12154"
            poststring = String.Format("username={0}&password={1}&{2}", username, password, docid)
            bytedata = Encoding.UTF8.GetBytes(poststring)

            request = WebRequest.Create(url)
            request.Method = "Post"
            request.ContentLength = bytedata.Length
            request.ContentType = "application/x-www-form-urlencoded"
            requestStream = request.GetRequestStream()
            requestStream.Write(bytedata, 0, bytedata.Length)
            requestStream.Close()
            request.Timeout = 60000

            Dim response As HttpWebResponse
            Dim responseStream As Stream
            Dim reader As StreamReader
            Dim sb As New StringBuilder()
            Dim line As String = String.Empty

            response = request.GetResponse()
            responseStream = response.GetResponseStream()

            reader = New StreamReader(responseStream, System.Text.Encoding.ASCII)

            line = reader.ReadLine()
            While (Not line Is Nothing)
                sb.Append(line)
                line = reader.ReadLine()
            End While

            File.WriteAllText(filename, sb.ToString())


        Catch ex As Exception
            MsgBox(ex.Message)
        End Try
        Return True

    End Function

Answer 1

我建议您简化代码并处理一次性资源，例如流和流阅读器。您也可以使用WebClient：

Using client = New WebClient()
    Dim values = New NameValueCollection()
    values.Add("username", "pdfuser")
    values.Add("password", "pdfuser")
    values.Add("docid", "inv12154")
    Dim result = client.UploadValues(url, values)
    File.WriteAllBytes(filename, result)
End Using

尝试使用HttpWebRequest在文件中加载页面

1 个答案: