Object reference not set to an instance of an object - when dealing with datetime fields

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Hi,

I am trying to display the systemDate where named as SystemCreatedOn. In that process, used the code as shown below:

var SystemCreatedOn = ((DateTime)Task.Fields[GUIDCollection.SYSTEM_CREATED_ON_GUID.ToString()].Value.Value).ToString("yyyy-MM-dd");

but i am getting error as "

Object reference not set to an instance of an object". Please help me resolving this error.

What I have tried:

Trying multiple ways to resolve this.

Posted 14-Sep-16 22:21pm

Member 8010354

Updated 14-Sep-16 23:24pm

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F-ES Sitecore 15-Sep-16 4:50am

This question is asked daily, please google before asking a question. Something you are referencing is null (ie something you are putting a "." or "[" after, so maybe Task, or Fields, or the result of Fields[..] etc). We can't run your code in context so we don't know. Use the debugger to find out what is null and either fix it so it isn't null, or change your code to handle the null, whichever is appropriate.

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Karthik_Mahalingam · Answer 1 · 2016-09-14T23:24:00

Validate for null on each object:

string SystemCreatedOn = "";
       string field = "";
       if (GUIDCollection != null && GUIDCollection.SYSTEM_CREATED_ON_GUID != null)
           field = GUIDCollection.SYSTEM_CREATED_ON_GUID.ToString();
       if (Task != null && Task.Fields != null && Task.Fields[field] != null && Task.Fields[field].Value != null && Task.Fields[field].Value.Value != null)
           if (field != "")
               SystemCreatedOn = ((DateTime)Task.Fields[field].Value.Value).ToString("yyyy-MM-dd");

For explanation, Refer Solution 1 & 2

OriginalGriff · Answer 2 · 2016-09-14T22:34:00

This is one of the most common problems we get asked, and it's also the one we are least equipped to answer, but you are most equipped to answer yourself.

Let me just explain what the error means: You have tried to use a variable, property, or a method return value but it contains null - which means that there is no instance of a class in the variable.
It's a bit like a pocket: you have a pocket in your shirt, which you use to hold a pen. If you reach into the pocket and find there isn't a pen there, you can't sign your name on a piece of paper - and you will get very funny looks if you try! The empty pocket is giving you a null value (no pen here!) so you can't do anything that you would normally do once you retrieved your pen. Why is it empty? That's the question - it may be that you forgot to pick up your pen when you left the house this morning, or possibly you left the pen in the pocket of yesterdays shirt when you took it off last night.

We can't tell, because we weren't there, and even more importantly, we can't even see your shirt, much less what is in the pocket!

Back to computers, and you have done the same thing, somehow - and we can't see your code, much less run it and find out what contains null when it shouldn't.
But you can - and Visual Studio will help you here. Run your program in the debugger and when it fails, VS will show you the line it found the problem on. You can then start looking at the various parts of it to see what value is null and start looking back through your code to find out why. So put a breakpoint at the beginning of the method containing the error line, and run your program from the start again. This time, VS will stop before the error, and let you examine what is going on by stepping through the code looking at your values.

But we can't do that - we don't have your code, we don't know how to use it if we did have it, we don't have your data. So try it - and see how much information you can find out!

Patrice T · Answer 3 · 2016-09-14T23:09:00

You should learn to use the debugger as soon as possible. Rather than guessing what your code is doing, It is time to see your code executing and ensuring that it does what you expect.

The debugger allow you to follow the execution line by line, inspect variables and you will see that there is a point where it stop doing what you expect.
Debugger - Wikipedia, the free encyclopedia[^]
Mastering Debugging in Visual Studio 2010 - A Beginner's Guide[^]

The debugger is here to show you what your code is doing and your task is to compare with what it should do.
When the code don't do what is expected, you are close to a bug.

Split this

C#

var SystemCreatedOn = ((DateTime)Task.Fields[GUIDCollection.SYSTEM_CREATED_ON_GUID.ToString()].Value.Value).ToString("yyyy-MM-dd");

with one operation per line, and use the debugger to see what happen on each step.

Object reference not set to an instance of an object - when dealing with datetime fields

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