C＃将FileStream复制到HttpPostedFileBase

Question

I am having problem to copy FileStream to HttpPostedFileBase. My code is something like this.

HttpPostedFileBase postedFile = null;    
FileStream f = new FileStream(Server.MapPath("Path"), FileMode.Open, FileAccess.Read);
postedFile.InputStream.CopyTo(f);
f.Close();

However I can read file but having error when try to copy f to postedFile. Please correct me if I am doing wrong or any problem in this code block. Furthermore, I am getting this exception:

"System.NullReferenceException: Object reference not set to an instance of an object."

Thanks in advance!

Answer 1

您的postedFile为null-这就是为什么您会得到null引用异常的原因。