How to know if Array FileInfo[] contains a file

Question

I have the following code, I receive an error at "if statement" saying that FileInfo does not contain a definition "Contains"

Which is the best solution for looking if a file is in a directory?

Thanks

string filePath = @"C:\Users\";
DirectoryInfo folderRoot = new DirectoryInfo(filePath);
FileInfo[] fileList = folderRoot.GetFiles();

IEnumerable<FileInfo> result = from file in fileList where file.Name == "test.txt" select file;
if (fileList.Contains(result))
{
      //dosomething
}

You already moved the files into result, don't you just want to check the contents of result now? — Kevin DiTraglia, Jun 13 '12 at 14:41
you are queryng filelist for result, then how can fileList not contain result ? — Felice Pollano, Jun 13 '12 at 14:42
Are you looking to see if *any* file is in a directory or if a *specific* file is in a directory? — Jay Sullivan, Jun 13 '12 at 14:45
@KDiTraglia yes, i want to check if the file "test.txt" is in the directory — Daniel Camacho, Jun 13 '12 at 14:49
@FelicePollano test.txt may not exist in the directory. At If statement i need to evaluate it. — Daniel Camacho, Jun 13 '12 at 14:50
@notfed if a specific file is in a directory, in this case "test.txt" — Daniel Camacho, Jun 13 '12 at 14:50

Grant Winney · Accepted Answer · 2012-06-13T14:56:46.937

Remove fileList.Contains(result) and use:

if (result.Any())
{

}

.Any() is a LINQ keyword for determining whether result has any items in it or not. Kinda like doing a .Count() > 0, except quicker. With .Any(), as soon as an element is found the sequence is no longer enumerated, as the result is True.

In fact, you could remove the last five lines of your code from from file in... to the bottom, replacing it with:

if (fileList.Any(x => x.Name == "test.txt"))
{

}

score 3 · Answer 2 · answered Jun 13 '12 at 14:44

3

you could check the count of result

 if (result.Count() > 0)
 {
    //dosomething
 }

answered Jun 13 '12 at 14:44

Dxsolo

51
5

Leng Weh Seng · Answer 3 · 2013-03-22T02:59:45.707

How about this, code below will give you a list of files (fullname as a string); the reason why return as a list is because your sub directories may have the same file name as 'test.txt'.

var list = Directory.EnumerateFiles(@"c:\temp\", "test.txt",
           SearchOption.AllDirectories);

if you are very sure 'test.txt' file will only in one of the directory, you can use:

string fullname = Directory.EnumerateFiles(@"c:\temp\", "test.txt",
                  SearchOption.AllDirectories).FirstOrDefault();
if (fullname != null) { ..... }

How to know if Array FileInfo[] contains a file

3 Answers3