CODEWITHSUNDEEP
c#.netinstantiation
Dave
Dave

Reputation: 8461

Check if object instantiated

I have an object which is made of many other objects! I am trying to find the value of of one of the properties (an enum) but can't.

Now, normally if I want to check if an object is null I can do

if (object == null)

but this results in the same error.

I tried

if (object.Equals(null)) and the same error.

The error message I'm getting is objectName threw exception: System.NullReferenceException: Object reference not set to an instance of an object..

I'm trying to determine if my object is instantiated or not. Now, I can stick this into a try catch, if it errors then I know it's not, but to me this feels very wrong (although I may not have a choice).

The other problem I have is this project isn't mine and is a black box to everyone and so I can't make any changes to the original object! This means, all I have is what I have got, an object which may or may not be instantiated and I need a way of telling.

Other than the try catch, do I have any other options?

EDIT

So, the object is

public partial class SaveBundleResponse 
{
    SaveBundleResponseHeader header;
}

public partial class SaveBundleResponseHeader 
{      
        private SaveBundleResponseHeaderStatus status;
}

public enum SaveBundleResponseHeaderStatus 
{        
        Success, Fail, OK, OtherStates
}

So the SaveBundleResponse is created initially, the instance is then passed through a 'workflow' style environment and each property becomes 'populated/updated' etc as it goes deeper into the workflow. However, in a few situations, the enum is never set.

The problem is, I need to know the value of the enum (or if it is null).

The code I am trying to use is

        if (saveBundleResponse.Header.Status // what ever happens, it fails at this point as Status is not initiated.

Upvotes: 12

Views: 26785

Answers (2)

ThoBa
ThoBa

Reputation: 515

You should be able to use something like this:

SaveBundleResponse sbr = ...;
if (sbr.Header != null && !sbr.IsDisposed)
{
    //Do the work
}

This should work (if the class is not a control you can't use the IsDisposed check).

Upvotes: 4

Sergey Berezovskiy
Sergey Berezovskiy

Reputation: 236218

if (saveBundleResponse != null)
{
    var header = saveBundleResponse.Header;
    if (header != null)
    {
        var status = header.Status;
    }
}

Upvotes: 10

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