WebClient.DownloadFile 路径问题

Question

I am using WebClient.DownloadFile to download an image to a local repository as follows:

            WebClient myWC = new WebClient();
            myWC.Credentials = new System.Net.NetworkCredential(username, password);
            string photoPath = @"\images\Employees\" + employee + ".jpg";
            myWC.DownloadFile(userResult[12].Values[0].Value.ToString(), photoPath);

My expected results were as follows: My web app is deployed here:

C:\\Inetpub\\wwwroot\\MyWebApp

I expected this to save the photo to

C:\\Inetpub\\wwwroot\\MyWebApp\\images\\Employees...

Instead, all my photos get saved here:

C:\\images\\Employees

I guess I don't completely understand the DownloadFile method because I felt like the path should be relative to the directory the app is deployed in. How can I change the path so that it is relative to the directory of the app?

Note: I don't want to use a physical path because I have a Dev and QA site and I don't want the paths to break if things get moved around.

Answer 1

在 ASP.NET 应用程序中，您可以使用Server.MapPath方法映射到网站内相对于站点根目录（由~表示）的物理文件夹：

string photoPath = Server.MapPath("~/images/Employees/" + employee + ".jpg");

Answer 2

The leading backslash in your photoPath makes the path an absolute path starting at the root directory ( C:\\ in your example). Do make it a relative path just remove the leading backslash:

string photoPath = @"images\Employees\" + employee + ".jpg";

Remark: DownloadFile(...) will not create the directory for you. Make sure it's there:

Directory.CreateDirectory("images\Employees");

Answer 3

string photoPath = @"images\Employees\" + employee + ".jpg";

doesn't work in powershell and gives the following error:

At line:1 char:22
+ string photoPath = @"images\Employees\" + employee + ".jpg";
+                      ~
No characters are allowed after a here-string header but before the end of the line.
    + CategoryInfo          : ParserError: (:) [], ParentContainsErrorRecordException
    + FullyQualifiedErrorId : UnexpectedCharactersAfterHereStringHeader