Need to check for null on something that throws exception

Question

_sponsorOrBankFacingBorrowerCompanyWizardData = CompanyData.GetCompanyWizardData(SponsorOrBankFacingBorrowerCompany.CompanyID);

So the problem here is that the code tries to go into this statement no matter what, I want it to only go if it CAN go, obviously.

However, if I perform a watch in Visual Studio 2010 ONLY on this object SponsorOrBankFacingBorrowerCompany, no properties, methods, anything, I get a null reference exception.

How do I check for null when I get an exception before the check even happens?

Here's the watch:

enter image description here

EDIT:

public STPProject STPData
        {
            get { return _STPData; }
            set
            {
                _STPData = value;

                //set WebIds
                foreach (STPCompany comp in _STPData.STPCompanyCollection)
                {
                    comp.WebId = comp.WebId < 1 ? GetNextWebId() : comp.WebId;
                    foreach (STPContact cont in comp.STPContactCollection)
                    {
                        cont.WebId = cont.WebId < 1 ? GetNextWebId() : cont.WebId;
                    }
                }

                //must be before AttachSTPEvents
                _STPData.AffiliateTradeIndicator = _STPData.AffiliateTradeIndicator.HasValue ? _STPData.AffiliateTradeIndicator.Value : false;

                //set company wizard defaults
                _sponsorOrBankFacingBorrowerCompanyWizardData = CompanyData.GetCompanyWizardData(SponsorOrBankFacingBorrowerCompany.CompanyID);

                AttachSTPEvents(_STPData);
            }
        }

Getter for other that is throwing exception:

public STPCompany SponsorOrBankFacingBorrowerCompany
        {
            get
            {
                if (STPData.AffiliateTradeIndicator.Value)
                {
                    return BankFacingBorrower;
                }
                else
                {
                    return Sponsor;
                }
            }
        }

You can't see the tree in the forest when it is scrolled off the right edge of the editor window. — Hans Passant, Mar 22 '11 at 13:36
What *is* SponsorOrBankFacingBorrowerCompany? If it is an object as you say, then the exception in the watch window is probably a debugger quirk. You can't get a null reference exception by checking if an object is != null. If SponsorOrBankFacingBorrowerCompany is a property though, it's possible the exception is thrown inside the getter code. — Misko, Mar 22 '11 at 13:40
I don't know what to tell you but I am, lol. It's within a setter overload. — slandau, Mar 22 '11 at 13:40
Can you post the code where SponsorOrBankFacingBorrowerCompany is declared? — Misko, Mar 22 '11 at 13:43
Check my answer below. For future referece, SponsorOrBankFacingBorrowerCompany is a "property" in this context, not an "object". — Misko, Mar 22 '11 at 13:50

Grant Thomas · Accepted Answer · 2011-03-22T13:53:09.867

3

Something like the following, unless I'm mistaking your question:

if (SponsorOrBankFacingBorrowerCompany != null)
{
    _sponsorOrBankFacingBorrowerCompanyWizardData = 
        CompanyData.GetCompanyWizardData(
            SponsorOrBankFacingBorrowerCompany.CompanyID);
}

Update:

Okay, this is elaborate but will hopefully make the problem become immediately evident, so let's drill this down, the long way; can you amend your property code to look like the following:

public STPCompany SponsorOrBankFacingBorrowerCompany
{
    get
    {
        if (STPData == null)
        {
            throw new InvalidOperationException("'STPData' is null");
        }

        if (STPData.AffiliateTradeIndicator == null)
        {
            throw new InvalidOperationException(
                "'STPData.AffiliateTradeIndicator' is null");
        }

        if (STPData.AffiliateTradeIndicator.Value == null)
        {
            throw new InvalidOperationException(
                "'STPData.AffiliateTradeIndicator.Value' is null");                ;
        }

        if (STPData.AffiliateTradeIndicator.Value)
        {
            return BankFacingBorrower;
        }
        else
        {
            return Sponsor;
        }
    }
}

edited Mar 22 '11 at 13:53

answered Mar 22 '11 at 13:29

Grant Thomas

44,454
10
85
129

That doesn't return a bool though, it throws an exception. Look at the edit, even though it's very small. – slandau Mar 22 '11 at 13:34
Okay - it would seem there is some operator overloading going on? I'm not 100%, but I'm sure we don't have the complete picture from data given in the question. – Grant Thomas Mar 22 '11 at 13:39
Yes exactly. This is within a setter overload. – slandau Mar 22 '11 at 13:39
_Pretty please_, can we see the code for `SponsorOrBankFacingBorrowerCompany`? Not just a property of it. – Grant Thomas Mar 22 '11 at 13:44
What is the value of `STPData.AffiliateTradeIndicator.Value` when you step through the code? – Grant Thomas Mar 22 '11 at 13:46
Yeah all this digging has shown me there is a more severe issue. Plus, I'm not really enjoying all of these custom getters and setters =/ – slandau Mar 22 '11 at 13:59
TBH, I thought so - hopefully this is enough to go by for now. :) – Grant Thomas Mar 22 '11 at 14:01

score 0 · Answer 2 · answered Mar 22 '11 at 13:47

0

I'm betting you're getting a null reference from your SponsorOrBankFacingBorrowerCompany getter in here:

STPData.AffiliateTradeIndicator.Value

Check all those parts in the debugger...

answered Mar 22 '11 at 13:47

Misko

2,044
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15

Need to check for null on something that throws exception

2 Answers2