Object reference not set to an instance of an object

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public HMIPGraphModel GetHMIPGraph(string currentIp, string dataSource, string geoId, string geoName)
        {
            var hmipGraphModel = new HMIPGraphModel();
            string baseUrl = CMHCConstants.HmiBaseUrl;
            hmipGraphModel.Geographies = new List<Geography_Region___City>();
            var scContext = new SitecoreContext();

            var reportTypeItem = scContext.GetItem<HMIReports>(dataSource);

            if (reportTypeItem == null)
            {
                Sitecore.Diagnostics.Log.Error($"[GetHMIPGraph] : Data source item {dataSource} not found", this);
                return null;
            }

            string reportType1 = reportTypeItem.Report1;
            string reportType2 = reportTypeItem.Report2;

            var geographyFolder = Sitecore.Context.Database.GetItem(HCConstants.HMIGeographyFolderPath);
            IEnumerable<Item> geoGraphyItems = new List<Item>();
            IEnumerable<Item> cityList = new List<Item>();
            if (geographyFolder != null)
            {
                geoGraphyItems = contentSearchAPI.GetIndexForRootItem(geographyFolder, IGeography_Region___CityConstants.TemplateId);
                if (geoGraphyItems != null)
                {
                    cityList = geoGraphyItems.Where(x => x != null && x.Fields["GeoID"] != null && !string.IsNullOrEmpty(x.Fields["GeoID"].Value));
                }
                else
                {
                    Sitecore.Diagnostics.Log.Info("HCWebHelper -> GetHMIPGraph - No Geography Items(s) found from Index", this);
                }
            }

            var geoIPInfo = LookupManager.GetInformationByIp(currentIp);
            var currentCity = geoIPInfo?.City;

            var currentGeographyId = string.Empty;

            if (geoId != null && geoName != null)
            {
                currentCity = geoName;
                currentGeographyId = geoId;
            }
            else if (currentCity == "N/A")
            {
                currentCity = "Delhi";
                currentGeographyId = "2070";
            }
            else
            {
                currentGeographyId = cityList.Where(x => x.Fields["GeoName"].Value == currentCity).Select(x => x.Fields["GeoID"].Value).FirstOrDefault();
                if (currentGeographyId == null)
                {
                    currentCity = "Delhi";
                    currentGeographyId = "2070";
                }
            }

            if (cityList != null && cityList.Any())
            {
                foreach (var city in cityList)
                {
                    var geo = scContext.GetItem<Geography_Region___City>(Guid.Parse(city.ID.ToString()));
                    if (geo != null)
                        hmipGraphModel.Geographies.Add(geo);
                }
            }
 
            hmipGraphModel.Geographies.Sort((x, y) => x.GeoName.CompareTo(y.GeoName));

            hmipGraphModel.CurrentGeographInfo = new Geography
            {
                GeoID = currentGeographyId,
                GeoName = currentCity
            };

            var reportUrl1 = string.Format("/{0}/Dashboard/{1}?geographyId={2}&t=3&geoName={3}", Sitecore.Context.Language.ToString().ToLower(), reportType1, hmipGraphModel.CurrentGeographInfo.GeoID, hmipGraphModel.CurrentGeographInfo.GeoName);

            var reportUrl2 = string.Format("/{0}/Dashboard/{1}?geographyId={2}&t=3&geoName={3}", Sitecore.Context.Language.ToString().ToLower(), reportType2, hmipGraphModel.CurrentGeographInfo.GeoID, hmipGraphModel.CurrentGeographInfo.GeoName);

            hmipGraphModel.ReportHtmlContent1 = CallHmiApi(reportUrl1, baseUrl).Result.Replace("/hmip-pimh", baseUrl);
            hmipGraphModel.ReportHtmlContent2 = CallHmiApi(reportUrl2, baseUrl).Result.Replace("/hmip-pimh", baseUrl);

            return hmipGraphModel;
        }

What I have tried:

I have tried the code as shown but i am getting the error:

Object reference not set to an instance of an object

Posted 20-Jul-20 20:04pm

@ksh@y

Updated 20-Jul-20 20:11pm

v2

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Comments

Sandeep Mewara 21-Jul-20 2:08am

At which line?

@ksh@y 21-Jul-20 2:15am

Line number is not mentioned in the logs

@ksh@y 21-Jul-20 2:15am

have i missed any initialization or any null check?

Sandeep Mewara 21-Jul-20 2:17am

That seems to be the case. Just debug and Visual Studio will tell you exactly which line is throwing this error.

Garth J Lancaster 21-Jul-20 2:09am

You might like to highlight the line where you get this error - use Improve question

2 solutions

Solution 2

Object reference not set to an instance of an object

This error happens when you try to use a property of an object that is null.

A simple use of Visual studio DEBUGGER can tell you the object because of which it is happening. Just look at the stack trace and put a debugger on that line. Check the objects of that line and see if any one is null and you are trying to use that objects property. Handle the same.

Posted 20-Jul-20 20:11pm

Sandeep Mewara

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OriginalGriff · Accepted Answer · 2020-07-20T20:10:00

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!