DirectoryInfo.EnumerateDirectories Method (String, SearchOption)
Returns an enumerable collection of directory information that matches a specified search pattern and search subdirectory option.
Assembly: mscorlib (in mscorlib.dll)
Public Function EnumerateDirectories ( searchPattern As String, searchOption As SearchOption ) As IEnumerable(Of DirectoryInfo)
Parameters
- searchPattern
-
Type:
System.String
The search string to match against the names of directories. This parameter can contain a combination of valid literal path and wildcard (* and ?) characters (see Remarks), but doesn't support regular expressions. The default pattern is "*", which returns all files.
- searchOption
-
Type:
System.IO.SearchOption
One of the enumeration values that specifies whether the search operation should include only the current directory or all subdirectories. The default value is TopDirectoryOnly.
Return Value
Type: System.Collections.Generic.IEnumerable(Of DirectoryInfo)An enumerable collection of directories that matches searchPattern and searchOption.
| Exception | Condition |
|---|---|
| ArgumentNullException | searchPattern is null. |
| ArgumentOutOfRangeException | searchOption is not a valid SearchOption value. |
| DirectoryNotFoundException | The path encapsulated in the DirectoryInfo object is invalid (for example, it is on an unmapped drive). |
| SecurityException | The caller does not have the required permission. |
searchPattern can be a combination of literal and wildcard characters, but doesn't support regular expressions. The following wildcard specifiers are permitted in searchPattern.
Wildcard specifier | Matches |
|---|---|
* (asterisk) | Zero or more characters in that position. |
? (question mark) | Zero or one character in that position. |
Characters other than the wildcard are literal characters. For example, the string "*t" searches for all names in ending with the letter "t". ". The searchPattern string "s*" searches for all names in path beginning with the letter "s".
The EnumerateDirectories and GetDirectories methods differ as follows:
When you use EnumerateDirectories, you can start enumerating the collection of DirectoryInfo objects before the whole collection is returned.
When you use GetDirectories, you must wait for the whole array of DirectoryInfo objects to be returned before you can access the array.
Therefore, when you are working with many files and directories, EnumerateDirectories can be more efficient.
This method pre-populates the values of the following DirectoryInfo properties:
The returned collection is not cached; each call to the GetEnumerator method on the collection will start a new enumeration.
The following example, starting from a specified directory, uses this method and the EnumerateFiles method to enumerate the files and directories within the start directory and display details of any files over 10 MB in size.
Imports System Imports System.IO Class Program Public Shared Sub Main(ByVal args As String()) Dim diTop As New DirectoryInfo("d:\") Try For Each fi In diTop.EnumerateFiles() Try ' Display each file over 10 MB; If fi.Length > 10000000 Then Console.WriteLine("{0}" & vbTab & vbTab & "{1}", fi.FullName, fi.Length.ToString("N0")) End If Catch UnAuthTop As UnauthorizedAccessException Console.WriteLine("{0}", UnAuthTop.Message) End Try Next For Each di In diTop.EnumerateDirectories("*") Try For Each fi In di.EnumerateFiles("*", SearchOption.AllDirectories) Try ' // Display each file over 10 MB; If fi.Length > 10000000 Then Console.WriteLine("{0}" & vbTab & vbTab & "{1}", fi.FullName, fi.Length.ToString("N0")) End If Catch UnAuthFile As UnauthorizedAccessException Console.WriteLine("UnAuthFile: {0}", UnAuthFile.Message) End Try Next Catch UnAuthSubDir As UnauthorizedAccessException Console.WriteLine("UnAuthSubDir: {0}", UnAuthSubDir.Message) End Try Next Catch DirNotFound As DirectoryNotFoundException Console.WriteLine("{0}", DirNotFound.Message) Catch UnAuthDir As UnauthorizedAccessException Console.WriteLine("UnAuthDir: {0}", UnAuthDir.Message) Catch LongPath As PathTooLongException Console.WriteLine("{0}", LongPath.Message) End Try End Sub End Class
Available since 10
.NET Framework
Available since 4.0
Silverlight
Available since 4.0