Question

在ftp位置放一些照片。我的控制器正在获取放置在ftp上的某些特定图像的路径列表。我想要做的是使用这些路径将这些图片下载到本地临时文件夹，然后在视图中显示它们。目前我正在努力与模型下载这些图片，但在尝试下载图片时遇到一些问题。下面发布的错误以及当前代码。还缺少文件夹创建代码。

这是我的控制器方法，它会获取路径列表，然后调用下载方法将图片从ftp位置下载到一些临时文件夹（这个临时文件夹应该是我的应用程序，然后视图可以打开该文件夹中的图像：

Function Details(Optional ByVal id As Long = Nothing) As ActionResult

        '--Temporary directory for pictures to be downloaded from ftp location (temp_dir) should be created besides application folders
        Dim temp_dir As String = "/temp_dir/"

        '--If not temp_dir exist ==> create this folder 
        '--if folder has been created properly go all next lines..

        '--Take list of all ftp paths e.g \someFolderForPictures\image1.jpg to be downloaded to temp_dir
        Dim PicsTrans As List(Of tblTransPics) = db.tblTransPics.Where(Function(f) f.IdTrans = id).ToList

        '--For each picture path download it to temp_dir folder with temporary name
        For Each imgFtpPath In PicsTrans
            Dim temp_picName As String = Guid.NewGuid.ToString
            DownloadFile(imgFtpPath.PicturePath, temp_dir & temp_picName)
        Next

        '-- If everythings went well - pass either temp_dir path to view and inside view those pictures will be opened or pass list of pictures (bytes)???
        Return View(temp_dir)
    End Function

下载文件方法：

Public Function DownloadFile(ByVal ftpPicLocation As String, destinationLocation As String) As Boolean
    Dim reqFTP As FtpWebRequest

    Try
        reqFTP = DirectCast(FtpWebRequest.Create("ftp://someftpserver.com" & ftpPicLocation), FtpWebRequest)
        reqFTP.Method = WebRequestMethods.Ftp.DownloadFile
        reqFTP.UseBinary = True
        reqFTP.Credentials = New NetworkCredential("myusername", "somepassword")

        Using outputStream As New FileStream(destinationLocation, FileMode.OpenOrCreate)
            Using response As FtpWebResponse = DirectCast(reqFTP.GetResponse(), FtpWebResponse)
                Using ftpStream As Stream = response.GetResponseStream()
                    Dim bufferSize As Integer = 2048
                    Dim readCount As Integer
                    Dim buffer As Byte() = New Byte(bufferSize - 1) {}
                    readCount = ftpStream.Read(buffer, 0, bufferSize)
                    While readCount > 0
                        outputStream.Write(buffer, 0, readCount)
                        readCount = ftpStream.Read(buffer, 0, bufferSize)
                    End While
                End Using

            End Using
        End Using
        Return True

    Catch ex As Exception
        Throw New Exception("Failed to download", ex.InnerException)
    End Try
End Function

此行发生错误：

  Using outputStream As New FileStream(destinationLocation, FileMode.OpenOrCreate)

它说：

 Cannot find part of path „C:\temp_dir\f0f43089-4a16-4229-8ea6-2c3a55fde2ae”.

顺便提一下C：\？

Answer 1

删除temp_dir变量中的第一个斜杠。

Dim temp_dir As String = "temp_dir/"

使用此斜杠表示您想要写入根目录。你的根等于C：\ 通过删除第一个斜杠，您可以在应用程序运行的文件夹下获得临时文件夹。

MVC从ftp下载图像并在VIew

1 个答案: