c# - AjaxFileUpload 获取文件流

Question

System.IO.Stream我想像这样使用 AjaxFileUpload获取文件。这是经典的 FileUpload 组件。

System.IO.Stream theStream = fileUpload.PostedFile.InputStream;

有人可以告诉我该怎么做吗？

Answer 1

如果您正在处理UploadComplete事件，那么您可以从事件参数的GetStreamContents（作为流）和GetContents（作为字节数组）方法中获取流AjaxFileUploadEventArgs

例如

protected void afu_OnUploadComplete(object sender, AjaxFileUploadEventArgs file) 
{ 
    using (var stream = file.GetStreamContents())
    {
        // Read the stream...
    }
}

您可以查看源代码中可用的内容AjaxFileUploadEventArgs- 远不止文档中的内容。

Answer 2

您可以暂时保存文件，然后读取它以获取您的 FileStream。它可能有点脏，但它对我有用。

VB.NET：

Dim tempPath As String = System.IO.Path.GetTempFileName()
yourAjaxFileUpload.SaveAs(tempPath)
Using fs As FileStream = File.OpenRead(tempPath)
    'Do stuff with fs here
End Using
File.Delete(tempPath)

C＃：

string tempPath = System.IO.Path.GetTempFileName();
yourAjaxFileUpload.SaveAs(tempPath);
using (FileStream fs = File.OpenRead(tempPath)) {
    //do stuff with fs here
}
File.Delete(tempPath);

Answer 3

如果有人想在您保存图像之前进行转换（例如：Png 到 jpg）。下面可能对ajaxcontroltoolkit中的asyncfileuploader有所帮助

   Protected Sub FileUploadComplete(ByVal sender As Object, ByVal e As EventArgs)
    Try
        Dim id As String = Session("MBRId")
        Dim contentType As String = AsyncFileUploadProfileImage.ContentType
        If (contentType = "image/jpeg" Or contentType = "image/png") Then
            Dim filename As String = System.IO.Path.GetFileName(AsyncFileUploadProfileImage.FileName)
            Dim TOjpegImage = System.Drawing.Image.FromStream(AsyncFileUploadProfileImage.FileContent)
            TOjpegImage.Save(Server.MapPath("img_prof/" + id + ".jpg"), System.Drawing.Imaging.ImageFormat.Jpeg)
            Dim Ext As String = System.IO.Path.GetExtension(AsyncFileUploadProfileImage.FileName)
            'Commented working save due to conversion of image above
            ' AsyncFileUploadProfileImage.SaveAs(Server.MapPath("img_prof/") + id + Ext)
            lblMesg.Text = "File Uploaded Successfully"


        Else
            lblMesg.Text = "We support only images of type jpg and png"
        End If
    Catch ex As Exception
        iHelperClasses.ErrorLogger.ErrorWriter("Method:FileUploadComplete()Error:" + ex.Message)
    End Try


End Sub