CODEWITHSUNDEEP
c#.netlinqc#-4.0
John
John

Reputation: 41

LINQ - Add static text to each result

I have an array of files, but the problem is the root path isn't attached to the file, so using the data below, how would I go about appending the linq item to the static string?

string rootPath = "C:\\Users\\MyUserName";

List<string> files = new List<string>();
files.Add("\\My Documents\\File1.txt");
files.Add("\\My Documents\\File2.txt");

I essentially want a list that is Path.Combine(rootPath, x); I tried this but no luck:

var fileList = (from x in files
               select Path.Combine(rootPath, x)).ToList();

But it doesn't append the rootPath, fileList is the same as the files list.

Any ideas?

Upvotes: 4

Views: 1287

Answers (2)

user372724
user372724

Reputation:

the query works fine if you change

"\\My Documents\\File1.txt" to @"My Documents\\File1.txt" .

The reason is being described in the post mentioned by Donut.

Hence,

string rootPath = "C:\\Users\\MyUserName";

List<string> files = new List<string>();
files.Add(@"My Documents\\File1.txt");
files.Add(@"My Documents\\File2.txt");

var fileList = (from x in files select Path.Combine(rootPath, x)).ToList(); 

OR

var fileList = files.Select(i => Path.Combine(rootPath, i));

works fine.

If at all you donot want to change the existing source , then instead of Path.Combine use string.Concat

e.g.

string rootPath = "C:\\Users\\MyUserName";

List<string> files = new List<string>();
files.Add("\\My Documents\\File1.txt");
files.Add("\\My Documents\\File2.txt");

var fileList = (from x in files select string.Concat(rootPath, x)).ToList(); 

OR
var fileList = files.Select(i => string.Concat(rootPath, i));

Hope this helps

Upvotes: 0

Donut
Donut

Reputation: 112855

Apparently Path.Combine will ignore the first parameter if the second parameter has a leading "\" (this blog entry has some more info).

This should work, it uses Path.Combine and the ? operator to account for leading slashes in the second parameter:

var fileList = (from f in files 
                select Path.Combine(rootPath, 
                f.StartsWith("\\") ? f.Substring(1) : f)).ToList();

Upvotes: 4

Related Questions