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DirectorySearcher.Filter Property

Gets or sets the Lightweight Directory Access Protocol (LDAP) format filter string.

[Visual Basic]
Public Property Filter As String
public string Filter {get; set;}
public: __property String* get_Filter();
public: __property void set_Filter(String*);
public function get Filter() : String;
public function set Filter(String);

Property Value

The search filter string in LDAP format, such as "(objectClass=user)". The default is "(objectClass=*)", which retrieves all objects.


The filter uses the following guidelines:

  1. The string must be enclosed in parentheses.
  2. Expressions can use the relational operators: <, <=, =, >=, and >. An example is "(objectClass=user)". Another example is "(lastName>=Davis)".
  3. Compound expressions are formed with the prefix operators & and |. Anexampleis"(&(objectClass=user)(lastName= Davis))".Anotherexampleis"(&(objectClass=printer)(|(building=42)(building=43)))".

When the filter contains an attribute of ADS_UTC_TIME type, its value must be of the yymmddhhmmssZ format where y, m, d, h, m, and s stand for year, month, day, hour, minute, and second, respectively. Note that the seconds (ss) value is optional. The final letter Z means there is no time differential. In this format, "10:20:00 A.M. May 13, 1999" becomes "990513102000Z". Note that Active Directory stores date and time as GMT time. If you specify a time with no time differential, you are specifying the time in GMT time.

If you are not in the GMT time zone, you can add a differential value to the GMT (instead of specifying Z) to specify a time according to your time zone. The differential is based on the following: differential = GMT- Local. To specify a differential, use the following format: yymmddhhmmss[+/-]hhmm. For example, "8:52:58 P.M. March 23, 1999" New Zealand Standard Time (the differential is 12 hours) is specified as "19990323205258.0+1200".


Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

.NET Framework Security: 

See Also

DirectorySearcher Class | DirectorySearcher Members | System.DirectoryServices Namespace