Using ASP.NET, how can I select multiple files through the same dialog

Question

I'm trying to upload some files to an ftp server from an ASP.NET page. Everything is ready however I would like to use an open file dialog to select the files I want to upload. How can I enable file upload to select multiple files, and if I can't, can I simply use the OpenFileDialog like a normal windows forms application ?

Thanks in advance

Answer 1

The issue is that in the context of a web application, you post data as a KeyValuePair. So a single <input type="file" name="Something" /> element can contain only one file because it is only one key.

An OpenFileDialog would be executed server side in a window there; the client would never see it.

Your options are to either limit to 1 file (and have a button to add another file upload), or move to a gmail like approach where you use a flash / plugin to get that functionality.

Answer 2

The standard HTML browse dialogue won't let you. However, there's a video on the official ASP.NET site called Multiple File Uploads in ASP.NET 2 that you should look at. There's some code based on that here .

Generally you would either use a Flash or JavaScript/AJAX based solution. There are plenty of controls available that can do this eg.

• http://www.codeproject.com/KB/aspnet/multiple_file_upload.aspx
• http://swfupload.org/
• http://ajaxuploader.com/

Just google 'multiple file upload' for far more.

Answer 3

我也在这一点上进行了研究，但是由于一个文件控件的局限性是一次只能选择一个文件，因此无法在一个文件控件中选择多个文件，因此您将需要多个文件控件来导入多个文件

Answer 4

将OpenFileDialog的MultiSelect属性设置为true。

Answer 5

Have a look here on how to upload multiple files. You have multiple FileUpload controls and use HttpFileCollection to get the files.

http://www.dotnetcurry.com/ShowArticle.aspx?ID=68&AspxAutoDetectCookieSupport=1

Answer 6

You may want to look at these SO posts:

How to select multiple files for upload?

Selecting Multiple Files for Upload in Web Page