Solved

Get key by idex from a ordered dictionary

Posted on 2006-10-24
8
4,474 Views
Last Modified: 2008-01-09
How can I retrieve the key by using the index?

I can retrieve the value by index like: oOrderedDictionary[0].toString()

Is there something similair for a key value?
(I believe a sortedlist has a GetKey() method, but the ordered dictionary does not?)
0
Comment
Question by:Kai77
  • 5
  • 3
8 Comments
 
LVL 9

Expert Comment

by:jonorossi
ID: 17795792
Have you tried using the TryGetValue method?
0
 

Author Comment

by:Kai77
ID: 17795845
I am using ASP.net 2.0 and intellisense does not say OrderDictionary has a TryGetValue method
0
 
LVL 9

Expert Comment

by:jonorossi
ID: 17795890
Is there a reason you are using System.Collections.Specialized.OrderedDictionary instead of System.Collections.Generic.Dictionary<TKey,TValue>
0
 

Author Comment

by:Kai77
ID: 17795986
from what i undestand an ordered dictionary the sort order is ordered by the order in which you addes key-value pairs. Does the generic.dictionary do the same?
0
Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

 

Author Comment

by:Kai77
ID: 17796028
I just took a quick look at the Generic.Dictionary .

I believe the TryGetValue needs you to enter a key and will return a value based on that key. What I need is to enter a index and get the key.
0
 
LVL 9

Expert Comment

by:jonorossi
ID: 17796034
If you require that the dictionary be sorted then you should use the generic SortedDictionary:

System.Collections.Generic.SortedDictionary<TKey, TValue>
0
 
LVL 9

Expert Comment

by:jonorossi
ID: 17796213
I see what you are after now. I can't seem to find what you are after in any of the collections built into .NET. For some reason none of them allow you to get the key by an index.
0
 
LVL 9

Accepted Solution

by:
jonorossi earned 500 total points
ID: 17796543
The reason you can't get the key by index with the SortedDictionary is because it is implemented as a binary tree. However, I am not sure why Microsoft didn't add a method to get the Key by index with the OrderedDictionary. Even the OrderedDictionaryKeyValueCollection which you get by going .Keys doesn't have a method to get out a key.

I was thinking get out the OrderedDictionaryKeyValueCollection from .Keys and enumerate the number of times to get to the index. But the GetEnumerator is declared internal so you can't use a foreach.

The only solution I can see is to build your own dictionary either from scratch or inherited from one of the .NET ones. Or try to get one off the internet. Or if you don't need it to be ordered you'd be able to use one of the .NET collections.

This one by Marc Clifton is pretty good http://www.codeproject.com/csharp/GenericKeyedList.asp
0

Featured Post

Is Your Active Directory as Secure as You Think?

More than 75% of all records are compromised because of the loss or theft of a privileged credential. Experts have been exploring Active Directory infrastructure to identify key threats and establish best practices for keeping data safe. Attend this month’s webinar to learn more.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Entity Framework is a powerful tool to help you interact with the DataBase but still doesn't help much when we have a Stored Procedure that returns more than one resultset. The solution takes some of out-of-the-box thinking; read on!
This article aims to explain the working of CircularLogArchiver. This tool was designed to solve the buildup of log file in cases where systems do not support circular logging or where circular logging is not enabled
Migrating to Microsoft Office 365 is becoming increasingly popular for organizations both large and small. If you have made the leap to Microsoft’s cloud platform, you know that you will need to create a corporate email signature for your Office 365…
Both in life and business – not all partnerships are created equal. As the demand for cloud services increases, so do the number of self-proclaimed cloud partners. Asking the right questions up front in the partnership, will enable both parties …

911 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

19 Experts available now in Live!

Get 1:1 Help Now