how to retrieve object value from an arraylist?

Question

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hai all,

i am trying to get arraylist form web service and trying to store it in new arraylist but it gives me the following error

following is the code i have used

display.MathService mymathservice = new display.MathService();
        object temp_result = mymathservice.display_messages(this.txtmessage.Text,"velu");
        final_result.Add(temp_result);
           for (int i = 0; i < final_result.Count; i++)
            {
                this.txtareamsg.Value += final_result[i].ToString();
            }

The error message says:
"Unable to cast object of type 'System.Object[]' to type 'System.Collections.ArrayList'."

Now tell me how should i retrieve value from an arraylist but rite now it gives me only system.object..i dont know how to find out index value exactly

please help me
thanks in advance

Posted 26-Apr-12 19:30pm

Iam Velu

Updated 26-Apr-12 21:13pm

v6

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Comments

hitech_s 27-Apr-12 2:00am

at what line you are getting error ?

Iam Velu 27-Apr-12 2:03am

now look at the questions i made changes ..i want to know how to retrieve object value from an arraylist

m@dhu 27-Apr-12 2:13am

I didn't get the purpose of using foreach loop in your code as that is not used.

Iam Velu 27-Apr-12 2:21am

i am just trying boss if u have solution for how to retrieve object value from an arraylist please put the sample code here atleast give me some idea how to execute tis successfully

2 solutions

Solution 1

You declare temp_result as of type object.
final_result.Add() accepts parameters of type System.Collections.Arraylist. The latter cannot implicitly be converted to the former.

If you know that display_messages() does return an ArrayList, then you should declare temp_result as such in the first place.
If it does not return an ArrayList, then it won't work at all.

Posted 26-Apr-12 20:45pm

lukeer

Comments

Iam Velu 27-Apr-12 2:53am

thanks for ur reply but i have even tried that way if i assign result like this also

final_result = mymathservice.display_messages(this.txtmessage.Text, "velu") as ArrayList;
or
final_result = (ArrayList) mymathservice.display_messages(this.txtmessage.Text, "velu");

then it shows type casting error

Error 1 Cannot convert type 'object[]' to 'System.Collections.ArrayList' via a reference conversion, boxing conversion, unboxing conversion, wrapping conversion, or null type conversion

lukeer 27-Apr-12 4:45am

That means that you cannot simply cast display_messages()'s return type to ArrayList.
Check the documentation. What type does display_messages() return?

Iam Velu 27-Apr-12 4:59am

i understand that..display messages return only arraylist i know that..i think the problem is this line i am creating object for calling webservices

display1.MathService mymathservice = new display1.MathService();

now with that object only i am calling display messages() method thatsy it shows error.is there any way to come out from this?please help me iam struck here

Iam Velu 27-Apr-12 5:00am

i am getting a build error so iam not even able to run the project and see what dsiplaymessages() is returning but i know from web services i am returning only arraylist

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

Iam Velu · Accepted Answer · 2012-04-27T00:31:00

hai all thank you i have solved this myself..thanks for the replies

C#

this.final_result = new ArrayList();
        livechat.MathService mymath = new livechat.MathService();
        object[] temp = mymath.show_initial_msgs();
        foreach (object o in temp)
        {
            final_result.Add(o.ToString());
        }
        if (final_result.Count == 0)
        {
         //do nothing
        }
        else
        {
            for (int i = 0; i < final_result.Count; i++)
            {
                this.txtareamsg.Value = final_result[i].ToString() + Environment.NewLine;
            }
        }

how to retrieve object value from an arraylist?

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how to retrieve object value from an arraylist?

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