Encasing a filename inside an app.config file using C#

Question

Is it possible to encase filenames inside an app.config file and use them in your code?

For instance, this code works perfectly:

string folder = @"C:\CDR_FTP1\ttfiles_exported\";

If I want to get the above value from an app.config file

1. is it possible to do that?
2. what would the syntax be?

For instance, inside the app.config, I could try and have something like this:

<add key="InputDir" value=@"D:\CDR_FTP1\ttfiles_exported\" />

I can't add the "@" because it will give me the following error:

"The character '@', hexadecimla value 0x40 is illegal at the beginning of an XML name."

If I try and use it in my code like below, it's fine, but where and how would I need to stick the "@" for the application to read it properly?

string folder = ConfigurationSettings.AppSettings["InputDir"];

Answer 1

Just use:

<add key="InputDir" value="D:\CDR_FTP1\ttfiles_exported\" />

There is no need to escape \ in XML attribute.

Answer 2

To expand Kirill's answer:

The special characters in XML attributes are different than those of C# strings.

In C# the character '\' is the string escape character, used to denote escape sequences such as '\n' for end of line, as you are probably aware; and hence needs to be escaped either as '\\' or by using @"".

In XML '\' has no especial meaning inside attribute values and can be use as is. This is not true for the '&' and '"' characters among others. If you wanted to include the value:

M & M "The chocolates"

in an app.config they would have to be escaped so:

<add key="SomeString" value="M &amp; M &quot;The chocolates&quot;" />