How to check if property exists

Question

I'm trying to read properties from DirectoryEntry. Unfortunately not all records have employeeNumber property so I need to check if it exists. I already tried:

a == one DirectoryEntry record
a.GetType().GetProperty("employeeNumber")==null //always returns true
String.IsNullOrWhiteSpace(a.Properties["employeeNumber"].ToString()) //exception

what else can I try?

Properties are usually written with PascalCasing, not camelCasing. How is your property defined? — Ondrej Janacek, Apr 15 '14 at 06:43
Can you try `bool doesExist = a.Properties.Contains("employeeNumber");`? — Ulugbek Umirov, Apr 15 '14 at 06:52

Rahul Tripathi · Accepted Answer · 2014-04-15T07:01:40.380

10

You can try like this:

OBJECT.GetType().GetProperty("PROPERTY") != null

So in your code it would be like:

var a = one DirectoryEntry record;
var pi = a.GetType().GetProperty("employeeNumber");
var value = pi.GetValue(a, null);

EDIT:-

Try this:

bool x = a.Properties.Contains("employeeNumber");

edited Apr 15 '14 at 07:01

answered Apr 15 '14 at 06:43

Rahul Tripathi

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It's not about reflection. It's about Active Directory. – Ulugbek Umirov Apr 15 '14 at 06:48
GetValue throws NullPointerException – szpic Apr 15 '14 at 06:49
@UlugbekUmirov:- Got that: bool x = a.Properties.Contains("employeeNumber"); What about this? – Rahul Tripathi Apr 15 '14 at 06:55
1

@szpic:- Try this:- bool x = a.Properties.Contains("employeeNumber"); – Rahul Tripathi Apr 15 '14 at 06:56
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Thx put this in answer and I'll accept – szpic Apr 15 '14 at 06:57
Propperties.contains only works when the attribute is not null. – Pieter Feb 21 '19 at 12:59

IliaJ · Answer 2 · 2014-04-15T07:01:28.873

1

Something like this:

a.Properties["employeeNumber"] == null || a.Properties["employeeNumber"].ToString().Length == 0

In your case a.Properties["employeeNumber"] can be null and you get an exception, trying to convert null to string.

edited Apr 15 '14 at 07:01

answered Apr 15 '14 at 06:47

IliaJ

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left side always returns false even if there is no `employeeNumber` right side is error because property doesn't have Length property – szpic Apr 15 '14 at 06:55

How to check if property exists

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