Get index from a Dictionary

[Luigi]

Hi all,
I have a Dictionary like this:

Dictionary<string, Object>

and I need to retrieve the index (0,1,2, etc) of a particular key (based on
dictionary insertion).

How can I accomplish this?

Thanks in advance.

 

[Jon Skeet [C# MVP]]

I have a Dictionary like this:

Dictionary<string, Object>

and I need to retrieve the index (0,1,2, etc) of a particular key (based on
dictionary insertion).

How can I accomplish this?

Dictionaries have no notion of insertion order - that information is
basically lost. If you need to maintain it, you'll need another data
structure (e.g. a list).

Jon

 

[Luigi]

Dictionaries have no notion of insertion order - that information is
basically lost. If you need to maintain it, you'll need another data
structure (e.g. a list).

Hi Jon,
and can I "pour" the keys collection of my Dictionary in a List, so I can
investigate the order of my strings?

Luigi

 

[Peter Morris]

and can I "pour" the keys collection of my Dictionary in a List, so I can

investigate the order of my strings?

No, you can inspect the order they were taken out of the dictionary and put
into the list. At best this will give you a current index; as soon as you
add a new value every index in the list could change, or non might.

What do you want to achieve?

 

[Luigi]

No, you can inspect the order they were taken out of the dictionary and put
into the list. At best this will give you a current index; as soon as you
add a new value every index in the list could change, or non might.

What do you want to achieve?

My problem is that this dictionary serve a datasource of DevExpress
TreeList, and I have to write some tests that verify that the strings (the
keys in the dictionary) appear in a prestabilite order in that control (like
user preferences).

Luigi

 

[Peter Morris]

Create a facade class that acts as the data source. Inside that class have
both a List and a Dictionary that you maintain. Use the dictionary for
quickly locating items based on their key, and the list for determining
items at a specific index.