How to process values of object within dictionary

Question

1.00/5 (1 vote)

See more:

I have the following code:

C#

Dictionary<string, object> dict= new Dictionary<string, object>();

someClass tmpClass = new someClass();

tmpClass.a = "blah";
tmpClass.b = "123";
tmpClass.c = "abc";

dict.Add("532Key", tmpClass);

// Now that the key and value (string and object) been assigned, how can I check if the ley is indeed "532Key" then get the values of tmpClass within the dictionary and process each element of the object assigning each to a class property (let call the new class newClass which have a,b, and c as properties). Thanks in advnce.

Posted 1-Aug-12 11:29am

Member 8714829

Updated 1-Aug-12 11:33am

Kenneth Haugland

v2

Add a Solution

Comments

Sergey Alexandrovich Kryukov 1-Aug-12 17:35pm

Does not seem to make sense. Why checking the key? If it is "523Key", it will be it all the time. You are missing something.
What do you mean by "class property"? A static property? (as others are "instance properties")? "Process each element of the object assigning each to a class property" really sounds like "assign each element to itself".
--SA

Christian Graus 1-Aug-12 17:45pm

He's clearly playing with a dictionary to understand the concept, not writing code he is going to use.

Member 8714829 1-Aug-12 18:35pm

hi Sergey, it will have other keys, I just used this key as an example. There is logic that will make use of the different keys in the dictionary that is why I have to do this sort of a check. the class I am using in my example have public strings/int that are using set and get.

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Christian Graus · Answer 1 · 2012-08-01T11:35:00

Solution 1

dict.ContainsKey lets you check if a key exists. You can iterate over dict.Keys and then look up each value as you go. But, you will struggle when you're using 'object', your best bet is to use the 'as' keyword to iterate over a list of possible types, and if you're doing that, you're better off strongly defining a class that contains those types. using string -> object will greatly complicate your code. string mapping to someClass would work way better.

Posted 1-Aug-12 11:35am

Christian Graus

Comments

Member 8714829 1-Aug-12 17:41pm

Thank you for your feedback, I wonder if you have an example of how to use "as" in looping through the object to read and assign each element. I will place this "if" statment first:
if(dict.ContiansKey["532key"])

{
do the looping to read and assign the values in the "object" - but not sure how to do it
}

Christian Graus 1-Aug-12 17:43pm

You would do something like

object o = dict["432key"];

someOtherObject soo = o as someOtherObject;
if (soo != null)
{
// It was of that type
}else
{
someObject so = o as someObject;
if (so != null)
{
// It was a someObject, so use it.
}

}

As you can see, this gets messy and ugly fast. Don't map to object if you can avoid it.

lewax00 · Answer 2 · 2012-08-01T11:38:00

Solution 2

First, if you know all values are going to be of type someClass, then change it from Dictionary<string, object> to Dictionary<string, someClass>. To access the value at "532Key", just use:

C#

var value = dict["532Key"];

(Note: If you leave it as-is, you'll need to cast value to the proper type before you can access any of it's properties!)

Posted 1-Aug-12 11:38am

lewax00

Comments

Christian Graus 1-Aug-12 17:43pm

Of course, if he does not know for sure that this key exists, this will throw an exception if it does not.

lewax00 1-Aug-12 17:46pm

Of course. But that's true for any collection, you can't read an entry from an invalid index. I guess I assumed the asker would already know that much.

Christian Graus 1-Aug-12 17:47pm

Yeah, but a dictionary is different, you know what your indices are in a list by getting the maximum. And he didn't seem to know about the Keys property.