从.NET下载大文件并在.NET中使用resume / retry支持？

How to implement downloading a large file (~500MB) from HTTP in my application? I want to support automatic resume/retry, so that when connection is disconnected, my application can try to reconnect to get the file and avoid re-downloading the downloaded part, if possible (I know, this depends on the server as well).How to implement downloading a large file (~500