How To Get The Value of XDocument Using C#

Question

Hi My Code Masters Trust you all are doing just fine. Please I want to get the Values of this Element ART from my XML files if the vale is ART i will then count Regimen else i will not. so i use this code int RegimenCounter = 0 ; string result =  ; if(!string.IsNullOrEmpty( result = xd .Descendants(PrescribedRegimenTypeCode).Single().Value)) { if ( result == ART) { RegimenCounter = xd .Descendants(Regimen).Count(); } } when i execute the code i am getting an exception error Sequence Contain no Element . it because the first XML file does not contain that Element PrescribedRegimenTypeCode while other files have in them. please i need your help to resolve this challenge. thank you

Nitin Sontakke · Answer

Honestly I am not sure if you can do the assignment and evaluation in one go. Because from my knowledge of C (which is almost nothing) all assignments always return true. Personally i think same is the case in C#. So you cannot write code like: if(!string.IsNullOrEmpty( result =SomeValueHere! ) Because as per my knowledge and belief (which I am ready to discard at submission of first proof!) the variable result will not be evaluation here. It is the result of assignment which is always true will be evaluated. As such this condition will probably always return true.

Abraham Olatubosun · Answer

Many thanks Manas Mohapatra i have tried your suggestion it works as long as the Element PrescribedRegimenTypeCode is found in the XML document but if it can't find it then it throw  Object reference not set to an instance of an object what do i do in issue like this i suggest i will need to check first if that Element is present but how can i do that please i need any help as 9 am of 25th of Nov 2016 is my deadline thank you

Manas Mohapatra · Answer

Try like below: XDocument xd = XDocument.Load(@ D:\ConsoleApplication4\MyData.xml ); string result2 =  ; result2 = xd.Element( Container ).Element( IndividualReport ).Element( Condition ).Element( Regimen ).Element( PrescribedRegimenTypeCode ).Value;

Nitin Sontakke · Answer

When you know that some files may have it and some may not the code as follows is too optimistic: result=xd.Descendants(  PrescribedRegimenTypeCode ). Single ().Value; Here you are accessing the property .Value of a node which is not found. So may be you should just call .Descendants first. See what it returns and then call .Single().Value on result later. Hope you get the point!

Abraham Olatubosun · Answer

Many thanks Nitin Sontakke  I noticed that too after evaluating the code i then rewrite it in this form : int Regimen = 0 ; string result =  ; result = xd .Descendants(PrescribedRegimenTypeCode).Single().Value; if( result ==ART) { RegimenCounter = xd .Descendants(Regimen).Count(); } when i execute the code i get the error at this point result=xd.Descendants(  PrescribedRegimenTypeCode ). Single ().Value; knowing that some files may not have PrescribedRegimenTypeCode while other will surely have. how can i resolve this issue thanks