Export (0) Print
Expand All

Directory.EnumerateFiles Method (String, String, SearchOption)

Returns an enumerable collection of file names that match a search pattern in a specified path, and optionally searches subdirectories.

Namespace:  System.IO
Assembly:  mscorlib (in mscorlib.dll)

'Declaration
Public Shared Function EnumerateFiles ( _
	path As String, _
	searchPattern As String, _
	searchOption As SearchOption _
) As IEnumerable(Of String)

Parameters

path
Type: System.String
The directory to search.
searchPattern
Type: System.String
The search string to match against the names of directories in path.
searchOption
Type: System.IO.SearchOption
One of the values of the SearchOption enumeration that specifies whether the search operation should include only the current directory or should include all subdirectories.
The default value is TopDirectoryOnly.

Return Value

Type: System.Collections.Generic.IEnumerable(Of String)
An enumerable collection of file names in the directory specified by path and that match searchPattern and searchOption.

ExceptionCondition
ArgumentException

path is a zero-length string, contains only white space, or contains invalid characters as defined by GetInvalidPathChars.

- or -

searchPattern does not contain a valid pattern.

ArgumentNullException

path is Nothing.

-or-

searchPattern is Nothing.

ArgumentOutOfRangeException

searchOption is not a valid SearchOption value.

DirectoryNotFoundException

path is invalid, such as referring to an unmapped drive.

IOException

path is a file name.

PathTooLongException

The specified path, file name, or combined exceed the system-defined maximum length. For example, on Windows-based platforms, paths must be less than 248 characters and file names must be less than 260 characters.

SecurityException

The caller does not have the required permission.

UnauthorizedAccessException

The caller does not have the required permission.

The following wildcard specifiers are permitted in the searchPattern parameter.

Wildcard character

Description

*

Zero or more characters.

?

Exactly one character.

You can specify relative path information with the path parameter. Relative path information is interpreted as relative to the current working directory, which you can determine by using the GetCurrentDirectory method.

The EnumerateFiles and GetFiles methods differ as follows: When you use EnumerateFiles, you can start enumerating the collection of names before the whole collection is returned; when you use GetFiles, you must wait for the whole array of names to be returned before you can access the array. Therefore, when you are working with many files and directories, EnumerateFiles can be more efficient.

The returned collection is not cached; each call to the GetEnumerator on the collection will start a new enumeration.

The following example recursively enumerates all files that have a .txt extension, reads each line of the file, and displays the line if it contains the string "Microsoft".


Imports System.IO
Imports System.Xml.Linq
Module Module1

    Sub Main()

        Try
            Dim files = From chkFile In Directory.EnumerateFiles("c:\", "*.txt", _
                                                 SearchOption.AllDirectories)
                        From line In File.ReadLines(chkFile)
                        Where line.Contains("Microsoft")
                        Select New With {.curFile = chkFile, .curLine = line}

            For Each f In files
                Console.WriteLine("{0}\t{1}", f.curFile, f.curLine)
            Next
			Console.WriteLine("{0} files found.", _
					files.Count.ToString())
        Catch UAEx As UnauthorizedAccessException
            Console.WriteLine(UAEx.Message)
        Catch PathEx As PathTooLongException
            Console.WriteLine(PathEx.Message)
        End Try
    End Sub
End Module


.NET Framework

Supported in: 4

.NET Framework Client Profile

Supported in: 4

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Community Additions

ADD
Show:
© 2014 Microsoft