[toyotajon93]

Hello everyone I am new to this and fairly new to c#, helping a friend write and enhance a program we use for a game we love. I'm getting a debug error at this code section. Specifically the first HttpWEbrequest. The error is NUllReferenceException. I've tried numerous things to get it fixed. My program will compile but crashes when this process is requested. Any help/advice would be great. I know programming fairly well but new to c#. Thanks

public void LogOnToEmross()
        {
            try
            {
                HttpWebRequest requestEvents = WebRequest.Create(string.Concat(new object[] { server.server, "game/get_cdinfo_api.php?key=", this.userkey.key, "&city=", this.userinfo.user.city[0].id, "&_l=en" })) as HttpWebRequest;
                using (HttpWebResponse response = requestEvents.GetResponse() as HttpWebResponse)
                {
                    StreamReader reader = new StreamReader(response.GetResponseStream());
                    if (reader.ReadToEnd().Contains("code:0"))
                    {
                        HttpWebRequest requestEvents2 = WebRequest.Create(this.server.server + "game/get_userinfo_api.php?key=" + this.userkey.key + "&_l=en") as HttpWebRequest;
                        using (HttpWebResponse response2 = requestEvents2.GetResponse() as HttpWebResponse)
                        {
                            string responseText = new StreamReader(response2.GetResponseStream()).ReadToEnd();
                            string[] seperator2 = new string[] { "\"ret\":" };
                            string[] temp2 = responseText.Split(seperator2, StringSplitOptions.None);
                            UserInfo testResult = Json.Deserialize<UserInfo>(temp2[1].Substring(0, temp2[1].Length - 3).TrimEnd(this.trimmer).TrimStart(this.trimmer));
                            this.userinfo = testResult;
                        }
                        this.GetChestsAndKeys();
                    }
                    else
                    {
                        this.LogOn();
                        this.GetChestsAndKeys();
                    }
                }
            }
            catch
            {
                this.LogOn();
                this.GetChestsAndKeys();
            }
        }

[tlhIn`toq]

First bug in my article:
What does this error mean?

toyotajon93: What this shows us is that you aren't familiar with breakpoints and how to debug your own code. Learning to debug one's own code is an essential skill. Sadly, one that apparently few college courses teach. Silly if you ask me.

Placing breakpoints and walking through the code line by line allows you to actually WATCH it execute.

Visualizing what your code does will let you see why it behaves the way it does.

It would be well worth your time to do the tutorials on FAQ 2. A couple hours learning this skill will save you hundreds of hours of confusion in one project alone.


See FAQ # 2. (Click the SHOW button below)



TOP most asked:
What does this error message mean?
FAQ 2: How do I debug
FAQ 3: How do I make Class1/Form1 talk to Class2/Form2


FAQ (Frequently Asked Questions - Updated July 2012

Spoiler

My program is broken:


• Q: My program doesn't work. I didn't show you any code or actually tell you the error message. How do I fix it?
  
  Spoiler

  A: What have you tried so far? It is a requirment of this site that you at least make an effort to research (read the MSDN) and code a good faith effort for your own problem. Can you share your current code with us and better explain what issues or errors you are getting?
  
  Give us something to go on
  
  
  
  
• Q: I do x and y happens which I didn't expect but I don't know how to figure out why. How do I debug and find my problem?
  A:
  Spoiler

  • Debugging video 1: Breakpoints and Local variables
    
  • Debugging video 2: Advanced breakpoints
    
  • Debugging tutorial
    
  • Debugging tips
    
  • Debugging in detail
    
  • Great debugging tips
    
  • It still doesn't work, article
    
  • Debugging tools survival guide
    
  • Video: Tips & Tricks to use Visual Studio to the fullest
    
    
    
  • 5 return dataset.Tables[tableName].Columns.Count;
    A condensed line like this makes a lot of assuptions that everything goes right, and gives you nothing to check or debug.
    
    If only for R&D / Debug purposes it can often be advantagous to break down the line
    
    

    if (dataset != null)
    {
       if (datase.Tables != null)
       {
          if (!string.IsNullOrWhiteSpace(tableName)
          {
             if (dataset.Tables[tableName].Columns != null)
    

    
    
    Now you can put a breakpoint on the top line and walk through it with F10 and check every object. You also don't try to manipulate a thing that doesn't yet exist.

  
  
  
  
  
  
  How do I?
  
  
• Q: ...get Form 'A' to make a change or talk to Form 'B'
  
  Spoiler

  
  NOTE: Don't try to access GUI controls across forms. Its wrong. Nobody will hire you if you do this sort of crap. It violates every guideline for 'black box' programming, Separation of Responsibility, loose binding of components, and event driven programming. Read the tutorials and learn to do it right the first time so you don't develop bad habits that you just have to un-learn later.
  A:

  • See this thread for the simplest of example code between two forms.
    
    The tutorials below actually teach and explain it further.
    
  • Passing values between forms/classes
    
  • Bulding an application - Part 1
    
  • Building an application - Part 2
    
  • Quick and easy custom events
    
  • Delegates, Lambdas and Events
    
  • http://www.codeproje...g-Windows-Forms
  
  
  
• Q: ...make a binary to int calculator
  A: Read my article
  
  
• Q: ...make a tabbed web browser?
  A: Read this thread
  
  
• Q: ...make a password/login form?
  A: Password handling tutorial
  
  
• Q: ... get all the sub-folders of a folder, and the sub-folders of those, to get all the levels of directories?
  A: [/b/Its a technique known as recursion.
  
  Spoiler

  
  The GetDirectories() method will get all the directories in a folder, then call itself with those directories... which in turn get all the subfolders and calls itself with those folders... which get all the subfolders and calls itself with those folders... Recursively calling itself as it drills down.
  
  It is demonstrated on the MSDN
  http://support.microsoft.com/kb/303974
  
  Found by Googling "MSDN Recursive Directory"
  
  
  
• Q: ... browse for/open a file?
  Read this tutorial
  
  
• Q: ...make a chat or client-server application?
  A:Client/server chat tutorial
  Peer-to-peer chat
  
  
• Q: ... get my program to programmatically simulate a mouse click or button press?
  A: Simulate mouse and keystroke (even to another application)
  
  
• Q: ... save data, save properties, save environmental variables, serialize my data/class?
  A:
  Spoiler

  • Separating data from GUI - PLUS - serializing the data to XML
    
  • Working with environmental variables
    
  • Writing a text file tutorial.
    
  • Reading a text file tutorial.
    
  • Easy Application Settings example
  
  
  
• Q:... get sound in my program?
  A: Adding sound to your C# application
  
  
• Q: ... use the serial port?
  A: Serial port communication
  
  
• Q: ...do compression or .zip files?
  A:
  • (de)Compression tutorial
    
  • Zip files tutorial
  
  
  
• Q:...do multi-threading? Having a problem with cross-threading...
  
  Spoiler

  A:

  • Cross thread calls tutorial
    
  • How to use a thread pool.
    
  • Decouple your multi-threaded work from the GUI so forms don't hang
    
  • thread synchonization
    
  • Advanced threading
    
  • MSDN asynch communication
  
  
  
• Q: ... make my textbox offer suggestions as the user types. (Autocomplete)
  A: Creating an auto-complete textbox
  
  
• Q: ... make a textbox just accept numbers and not letters?
  A: Read this thread
  
• Q:I get an error when I try to use a textbox for numeric values and the user types non-numbers. What do I do?
  A:
  Spoiler

  We see this a LOT, especially with rookies using textbox for numeric input.
  
  Any input that can't be converted to a number will do this.
  "5" can become 5
  "yogi" cannot become a number
  string.empty cannot become a number
  
  You would be best off changing from a textbox to a NumericUpDown or to inherit from textbox to make a numerictextbox.
  
  There are a LOT of articles on making a NumericTextBox. Try googling "C# NumericTextBox" and you should find a lot, such as this one on the MSDN:
  http://msdn.microsof...4(v=vs.80).aspx
  
  Once you study the code you'll see that as each key is pressed it is checked to see if it is a number. If not, then it is ignored. Thus the user can only enter numerically valid values.
  
  
  
• Q: ... use PInvoke and the Win32 api calls to get functions not available in .NET framework?
  A: Using the Win32 API Tutorial
  
  
• Q: ... have both a WinForms Windows app, and still have a Console window open?
  
  Spoiler

  A: Make your new project a WinForms project. Then go back to project properties (Right-click on the project, select Properties).
  
  On the Application tab go to the dropdown that says "Windows Forms" and change it to "Console Application." You now have a WinForms application with a console window. I do this on occassion to see my Console.WriteLine statements when I am debugging. But don't consider this mixed mode operation a proper way to release an application for real-world use.
  
  
  
• Q: ... make a username/password logon (login) system?
  A: Read this tutorial
  
  
• Q: ... make global hotkeys?
  A: Global Hotkeys Tutorial
  
  
  
  
  
  Can someone explain...
  
  
• Q: ...Why my multi-thread throws a cross-threading error when it tries to update my GUI?
  A: Your thread shouldn't be trying to affect any GUI at all: Ever.
  
  Spoiler

  
  

  Quote

  But when I kick off the background worker and it goes to change a label in this panel

  
  
  I'll stop you right there. That underlying principal for your program is the problem and just won't work. The worker is a different thread than the one that created the GUI.
  
  Background threads do not, ever, directly access anything that they didn't make. Period. Accept that and start re-designing.
  
  Background worker raises events. You main class that makes this background worker has to subscribe to those events. Then that thread can update its GUI.
  
  This is how is it meant to work. Each 'thing' in a program really should have only one purpose in life and cause no side affects. The background worker should do its job and nothing else. Its job is not to manage the GUI. The GUI thread's job is to manage the GUI.
  
  Think of it this way: Your car dashboard has one job: To be the GUI for your car. But if the speedometer dies you don't want that to keep the engine from starting. The speedometer and the engine are 'loosely bound' for a reason. Your program is the same. You need the GUI to run whether or not the background worker does, and you want the background worker to run regardless which GUI you have on display.
  
  So the background worker is kept ignorant of which panel you have up. It just says "I'm 50% done". If you have the simple panel or the complex panel on display doesn't matter. It hears the event and does whatever it is designed to do to display those results. Maybe the simple panel uses a progress bar, while the advanced panel display the exact percentage. The background thread doesn't know or care how it is shown.
  
  

  Quote

  So my main application should make a dozen threads to update the dozen similar controls?

  
  
  To me that sounds like the main application is doing too much work and micromanaging the other controls. If the main application is coded for 12 background threads and panels, what happens in 6 months when you want to add a couple more panels? You have to update all your infrastructure to support them.
  
  Personally I would make UserControls that consist of the Panel, its own backgroundworker and any pure objects that you might want to serialize for later restoration. The idea is to make a complete and fully self-contained 'Lego Block' of functionality. Then use your application to just hook them all together.
  
  Now you can place 2 of your custom controls on screen... or 20... and they each take complete care of themselves. Only when one of your custom controls raises an event like LogThis(string message) or HighLevelWarning(int level) does the application have to do anything. The bulk of the work is done within the UserControl
  
  In each of these UserControls I would create methods for Start() and Stop(). Let the UserControl handle its own needs.
  
  Your main application should do nothing more than:
  
  

  StartAllPanels()
  {
     foreach(CustomPanel cp in myPanelsCollection)
     {
        cp.Start(); // Tell the panel to start
        cp.WarningMessage += WarningHandlerMethod; // Subscribe to warning event
        cp.LogThis += LogMessageHandlerMethod; // Subscribe to logging event
     }
  }
  

  
  
  See how your main application has no idea what the panel needs to do to start up? It doesn't try to micromanage the panel and tell it to start it's backgroundworker. The main app is blissfully ignorant of the inner needs of the component. Its like a the driver of a car. The driver doesn't tell the car: Close 12v power, start fuel pump, begin ignition computer, calibrate fuel/air mix, confirm foot is on brake, start ignition... The driver just turns the key to Start(). Your application should be the same. It only needs to know what it NEEDS to know. Let the rest of the parts take on as much responsibility as you can push on them.
  
  Spending a little time on these tutorials before writing any more code should help you with a better understanding of all this and enable you to architect a better blueprint for your application. Work smarter not harder.
  
  The tutorials below walk through making an application including inheritance, custom events and custom controls, object serialization and more.
  Quick and easy custom events
  Bulding an application - Part 1
  Building an application - Part 2
  Separating data from GUI - PLUS - serializing the data to XML
  WPF version (WPF-MVVM data binding)
  Passing values between forms/classes
  Decouple your multi-threaded work from the GUI so forms don't hang
  
  
  
  
• Q: What are lambdas? What Is (Obj, E) => ?
  A: Excellent article by Curtis Rutland
  
  
• Q: ... how to do x, y, z with the HTML that comes out of a website ...
  A: Check out the HTML Agility Pack. Yes its free.
  
  
• Q:... how to do x,y,z with a database {probably for the first time}...
  A: Read this tutorial
  Entire section of tutorials
  Parameterizing Your SQL Queries: The RIGHT Way To Query A Database.
  Using SqlDependency to monitor SQL database changes
  
  
• Q: Can someone explain bitwise operations?
  A: Terrific explanation by CodingSup3rnatur@l-360. Be sure to +1 him for this thread.
  
  
  
  
  
  
  I'm lost while learning xyz... I don't know where to begin...
  
  
• Q:I'm trying to teach myself programming. I'm writing a program to do xyz, rather than following a guided self teaching book or lesson plan or on-line tutorial because I just don't learn from books.
  A:
  Spoiler

  I'm sorry for how this sounds. I tend to take the stance that I can do you more good and give you more long-term meaningful help by being frank and give you adult-level honesty. I don't feel it does anyone any good to coddle them and do nothing but blow sunshine and rainbows up their skirt. I'd rather say something
  to motivate you than feel my place is to bolster your false high self esteem.
  
  

  Quote

  ]
  I've tried going through those, the only way im learning is through struggling to write code from scratch, the thought process i guess is helping me, i've tried reading sooo much and watching videos but honestly I'm not learning until I actaully type it.

  
  
  I hear this a lot and the only thing I can think is students are buying the wrong books. Or they read the information and don't feel they need to actually work the lessons/exercises. This argument sounds like there are only two choices:
  

  • Develop from scratch even though they haven't learned the language yet.
    
  • Just read C# dictionaries.

  
  
  Maybe this is from students buying the course textbook and reading it on their own, without the benefit of the teacher and their lesson plan and exercise assignments. When one mis-uses the materials, or only has 25% of the materials, of course they won't learn.
  
  Here's a tip when selecting a book: If it is a dictionary of the language it is not a teaching book. Titles like "C# 4.0, The Complete Language" are not teaching books. If the title includes the words "Learn" or "Master" or "Teach" they might be teaching books. "Learn C# in 21 days", "Master C# in 2 hours a night", "Head First C#, A self-teaching guide" Then they are probably teaching books with a lesson plan and exercises to help you build up skills.
  
  Obviously you didn't read the resources list I posted or get any one of the NUMEROUS self-teaching books.
  
  Self-teaching books HAVE YOU TYPING CODE. They are NOT just reading as you describe.
  
  C# is a language just like Russian or English. You cannot learn Italian by just reading an Italian dictionary.
  
  Or even reading an English-to-Italian dictionary. You have to take lessons and do the learning exercises. Those lessons and exercises are developed by professionals to take place in a sequence proven to work, by taking the student from simple to complex concepts. You did not learn how to compose literary works in English by just reading a dictionary. You worked at lessons that taught you the syntactical use of verbs, nouns, additives and so on. You worked lessons that had you build simple things first like "Those are my apples. These are your pencils", and worked up from there.
  
  So why are you trying to "just read" to learn C#? Or why are you insisting on trying to design and code a working program without first learning the language? It makes no sense! Its like saying you have to design and write a mystery novel as your introductory educational process to learn German. Its just a fraking ridiculous argument to try to take or defend.
  
  There are numerous on-line learning series on the internet that have you learning and WRITING code, not just reading. We have them right here on DIC and they have been linked to you several times. There are many good guided self-teaching books, that once again are NOT just reading but teaching through proven methods of:
  

  • Introduce new material
    
  • Have student exercise with new material

  
  
  Yet you insist that you don't need to go the route that has worked for the 3 generation of coders before you:
  
  Representatives of which are here TELLING you that is the way to learn this science/skill/art.
  
  

  Quote

  would i be able to take out the private double[] months = new double[12];
  and place it in a method instead of leaving it in a private field, why does it have to be in a private field as opposed to a method in just placing it in the main method?

  
  
  Questions like this last one show just how badly you need to stop trying to write this program and just concentrate on learning the language through some sort of guided lesson plan. This question is filled with so much lack of understanding that it is hard to know where to start in an effort to answer it. To answer this someone would have to back up 5 chapters and help you get a grasp of certain introductory concepts. It's not right to ask that of people that have already devoted tens or hundreds of hours to develop the tutorials we have here. You shouldn't be asking them to repeat themselves because you feel you need special hand-holding or because you don't want to get the right books or because you don't want to actually work the exercises in the books or tutorials.
  
  
  
  
  
• Q: I'm making a maze generator/solver and...
  A: http://www.codeproje...enerator-Solver
  
  
  
• Q: I am making a calculator as my school homework project and ...
  A: Calculator tutorial
  
  
• Q: I've been struggling with this for days/weeks and I can't figure it out and my professor is worthless and can't teach. Can someone here explain it to me?
  A:
  Spoiler

  If you are struggling with how to do this you need to talk to your professor. Let him/her know you are struggling at this early stage in class. Make your professor do the job (s)he gets paid to do by either helping you or finding you a tutor or giving you more exercises from earlier in the book. You are paying for this education. Be an active part in not allowing the teacher to brush you off and let you slip through the cracks. If the other 50 people in class aren't struggling then don't blame the teacher. If the other 50 people are struggling then you all need to go to the professor's superior and tell him/her. If the prof is really incompetent then you don't need to help him keep his cushy 100,000/year job. If the prof isn't incompetent then you need to study harder or consider buying another book on programming. You aren't required to ONLY use the text book provided for the class.
  "How do you resolve your issues" survey.
  
  
  
  
• Q: I am doing a dice game for a school homework and...
  A:Drawing dice on the console
  
  
  
  
• Q:

  Quote

  Hi,I'm currently learning C# in class at the moment and I'm a little bit stuck on what this question means.[...]show me where I can get help,
  
  A:
  Spoiler

  Your professor. That's where to start for a couple reasons:
  1. They are getting paid to teach you. If they aren't teaching you this needs to come to their attention and that of their superiors.
  2. You're the one paying them. Tens of thousands of dollars for your education. You need to learn to take every ounce of knowledge you can from these teachers and not sit passively back and try to learn it on the outside. If you were going to do that then you didn't need to take out all the student loans that are going to keep you in
  
  debt for the next 15 years.
  3. You need to let the teacher do their job. If you are struggling here you don't want to hide it. You need them to be aware of position so they can give you the time and attention you need. Otherwise you will be a little lost on chapter 1. A little more on 2. Way behind by chapter 3. You have to get a good foundation now if you are to gain anything in the later lessons.
  
  
  
• Q: I want to write a program that does x, y and z with features for A, B, and C. {Notice there is no question in this question}
  A:
  Spoiler

  That is a very good statement of intent. Go right ahead. You don't need to announce your intentions to us, nor get anyone's permission. After you have made an effort to your own code (in good faith as described in the Welcome DIC email you got when you joined) and the forum rules that I'm sure you read before posting, and you have a QUESTION about this project... Please post the QUESTION here in this same thread.
  
  There is no need to start a new thread for this same topic.
  
  
  
• Q: I need to code to do x... Someone tell me the code for y...
  A:
  Spoiler

  Your question is about to get bounced for begging for code anyway but...
  So you're asking the volunteers here to write your code for you, to make it do everything in your wish list?
  
  Please read the rules.
  
  You seem to misunderstand what we do here. We help people learn to code. We help people with their projects. We help people better understand the errors and exceptions they are getting so they can fix their issues. We are not a free code writing service. If you have made an effort to code a specific feature, but are not getting the results you wanted then please post the relivant code for that feature along with the error messages or an explanation of what results you are seeing as compared to the results you were expecting, and we will try to guide you onto the right path.
  Read this article!!!!!
  
  
  
  
  Discussion topics:
  
  
• Q: What is the best programming language/OS? What programming language/OS should I learn?
  A:
  Spoiler

  All of them. And none of them. You might as well be asking "What is the best kind of vehicle?" Because the answer for both questions is "It depends on your needs and what personally suites you the best." C, C++, C#, Objective-C, Cocoa, F#, Visual Basic, Python, JAVA...
  
  Are all good languages. They all have their pros and cons. They each have their strengths and weaknesses. Some have stronger footholds in some markets than others. Do you want to write for iPhone/iPad then you need Objective-C. Do you want to write for generic mobile phone use then you need JAVA. And so on. If you have no idea what area of programming you want to move to (Gaming, Financial, Windows, Macintosh, Cell phones) then nobody can advise you on a language. Personally, I would point you to C# because, like it or not, Microsoft owns the desktop computer market and C# will teach you good habits of design, OOP (Object Oriented Programming) design, inheritance and so on: Concepts that translate well to all other OOP languages.
  
  The OS is a by-product of the type of coding you want to do, which in turn dictates the language you need, which then decides the operating system you probably need. Not the other way around.
  
  Do you want to code apps for iOS devices like the iPad and iPhone? Then you need a Macintosh to do it right. Are you hankering to do machine vision programming? Industrial robot control? Financial applications?
  
  What are your programming goals? Do you want to market $9.99 desktop applications to the masses? Do you want to make control systems for helicopters? XBox games requires the .NET XNA framework so you are now in Windows. Do you want to do embedded controls for automotive computers? Do you just love MS Office and love to make extensions for it? Do you want to work on web apps or desktop apps or mobile apps?
  
  Do you now see why we can't even begin to tell you what is best for you? Only you know what you like and what you don't like. Only you know what area of programming is interesting to you. If you ask me for advice I might tell you video processing for the movie industry is great so you should get a Mac. Someone else is going to tell you cool stories of working on CSI lab equipment so you should do C embedded stuff.
  
  The short answer for this question is: Get in touch with your own wants and needs then think for yourself.
  
  Join these discussions on the topic:
  Which coding language?
  VB6 is dead
  C# or C++?
  
  
  
  
• Q: How do I become a programmer?
  A: Click the link
  
  
• Q: I'm not really sure what I want to do with my future? Do you guys like programming? I think I kinda like math and games and computers? What should I do or study?
  A:
  Spoiler

  
  You are asking a very vague, generalize question about a broad topic.
  You might as well be asking... What is the best kind of vehicle to buy? Or what is the best kind of plastic to make? It all depends on your needs... Your area of business.
  
  If you are interested in embedded devices like computers that control automobile engines it is still programming - but it is entirely different to writing a point of sale program meant to be used as a self-service kiosk like you see at Home Depot. And that is entirely different to writing a program that is meant to be used on a mobile platform.
  
  You need to make a decision about what kind of programming, what area of interest, what industry you want to work in, before you can worry about the specifics of which language and OS and platform.
  Which Language Should I Learn?
  DIC Tutorials Section
  Good thread on the topic
  Get experience while you find yourself
  
  
  
• Q: What's your installation like? What sofware do you use? What are your Visual Studio extensions?
  A:
  Spoiler

  
  

  • Host Operating System - 16gig, quadcore, 3x24" Dell LCDs at 1920x1200 (2 landscape, 1 portrait)
    
    • 20 times of on-line update/reboot cycle
      
    • Device Drivers
    • AVG antivirus
      
    • VMware workstation
    
    
    • VM Operating System
      
      • 20 times of on-line update/reboot cycle
        
      • Device Drivers
        
      • Visual Studio
        
        • ReSharper
          
        • Dotfuscator
          
        • CodeMaid
          
        • XAML regions
          
        • XAML code cleanup
          
        • InstallShield
        
        
      • Expression blend studio
        
      • MS Office
        
      • SnagIt
        
      • Safari
        
      • iTunes
        
      • Fences
        
      • Yahoo messenger
        
      • FoxIt PDF reader
        
      • AnyDVD (I have DVDs from 3 different regions)
        
      • TightVNC
        
      • Dropbox
        
      • AVG anti-virus
        
      • Quicken
        
      • Canon RAW codec
        
      • Shark007 codec pack for Media Center
        
      • Another 20 rounds of on-line update/reboot
        
      • Take a snapshot of the VM machine for easy restoration

  
  
  That is my entire install
  
  
  
  
  
  
  Working for myself/Deploying/Selling software:
  
  
• So you want to be a game programmer...
  
  
• Q:How do I stay a free lance coder for a living?
  A:http://justcreatived...eelancing-life/
  
  
• Q: How do I become a better coder?
  Read this, and practice a lot.
  How to be a better coder
  
  
• Q: Are there any resources for small C# projects a novice to become a better coder?
  A:
  Spoiler

  There is a novice projects thread here on DIC. But here's my advice whenever this comes up:
  
  Look around. Anyone who can't find a dozen projects a day by just walking through life, is doing so with their eyes closed to the world.
  

  • Do you like the weather? What about a program to get the various weather reports from different web sites?
    
    Or to integrate with one of the numerous USB weather station hobby kits on the market?
    
  • Do you like the run? What about a program to log your runs, routes and progress?
    
  • Do you like movies? What about a program to catalog all your DVD's and AVI's?
    
  • Do you like photography? What about a program to browse your images, assign tags and GPS?
    
  • Do you like shooting? What about a program to track your aim and improvement?
    
  • What about every time you walk into a business and someone says "Oh, I'm sorry. The computers are slow/suck.
    
    This is going to take 10 minutes and 25 screens." Sounds like an opportunity to make and maybe even sell them a new program. So go home and make it first before you open your mouth. If you succeed in something great. If you fail, then you know where to study more and you haven't embarrassed yourself.

  
  
  What about every time you walk into a business and someone says "Oh, I'm sorry. The computers are slow/suck. This is going to take 10 minutes and 25 screens." Sounds like an opportunity to make and maybe even sell them a new program. So go home and make it first before you open your mouth.
  
  If you succeed in something great. If you fail, then you know where to study more and you haven't embarrassed yourself.
  
  Go to any of the on-line coder for hire sites. Read the new contract descriptions. DON'T BID ON THEM. Just read them. This will tell you what is requested by employers so you know where you have the potential to make money, and tell you where you should study. Then pick a project and build it. TRACK YOUR TIME. If you don't know how
  
  long it takes you to build a project then you won't be able to bid on contracts. If you bid $50 for 50 hours of work you're going to starve to death. Again, building projects just to learn the technology and learn your own speed and weaknesses is something we all do/did and you need to do too. Once you can build a project just for the learning experience, fast enough that you could have made a competitive bid... Now you can start considering actually bidding on new contracts that are in your skill set.
  
  
  
  
• Q: How do I sell the software I've developed?
  A:http://www.dreaminco...m_notifications
  
  
• Q: How do I decide how much to charge for my application?
  A: Read this
  A lot of questions about freelancing were covered in the Q&A with the Experts thread
  
  
• Q: How do I deploy my program / Make an installer?
  [b]A: C# application deployment project
  Include the smallest .NET possible

---

This post has been edited by tlhIn`toq: 04 August 2012 - 07:03 AM

[toyotajon93]

I agree, I have not had a ton of experience debugging. I will read the faq as you mentioned. Thanks, any advice on the code itself?

[MrShoes]

Is server instantiated before the method is called?

Which line are you getting the exception on (as highlighted in VS)?

Where is the method being called from?

There are too many unknown factors to resolve your problem. In the meantime, I recommend reading up on NullReferenceException - understanding what exceptions mean will help you resolve bugs.

[toyotajon93]

Server is called here, I can send you the project if interested.

private void LogOn()
        {
            try
            {
                HttpWebRequest request = WebRequest.Create("http://m.emrosswar.com/info.php?user=" + activeUser.SelectSingleNode("username").InnerText + "&action=login&pvp=0") as HttpWebRequest;
                using (HttpWebResponse response2 = request.GetResponse() as HttpWebResponse)
                {
                    string responseText = new StreamReader(response2.GetResponseStream()).ReadToEnd();
                    string[] seperator2 = new[] { "\"ret\":" };
                    string[] temp2 = responseText.Split(seperator2, StringSplitOptions.None);
                    ServerInfo testResult = Json.Deserialize<ServerInfo>(temp2[1].Substring(0, temp2[1].Length - 3).TrimEnd(trimmer).TrimStart(trimmer));
                    server = testResult;
                }
                request = WebRequest.Create(server.server + "game/login_api.php?username=" + server.user + "&password=" + activeUser.SelectSingleNode("password").InnerText) as HttpWebRequest;
                using (HttpWebResponse response3 = request.GetResponse() as HttpWebResponse)
                {
                    string responseText = new StreamReader(response3.GetResponseStream()).ReadToEnd();
                    string[] seperator2 = new[] { "\"ret\":" };
                    string[] temp2 = responseText.Split(seperator2, StringSplitOptions.None);
                    Login testResult = Json.Deserialize<Login>(temp2[1].Substring(0, temp2[1].Length - 3).TrimEnd(trimmer).TrimStart(trimmer));
                    userkey = testResult;
                }
                request = WebRequest.Create(server.server + "game/get_userinfo_api.php?key=" + userkey.key) as HttpWebRequest;
                using (HttpWebResponse response4 = request.GetResponse() as HttpWebResponse)
                {
                    string responseText = new StreamReader(response4.GetResponseStream()).ReadToEnd();
                    string[] seperator2 = new[] { "\"ret\":" };
                    string[] temp2 = responseText.Split(seperator2, StringSplitOptions.None);
                    UserInfo testResult = Json.Deserialize<UserInfo>(temp2[1].Substring(0, temp2[1].Length - 3).TrimEnd(trimmer).TrimStart(trimmer));
                    userinfo = testResult;
                }
            }
            catch
            {
                MessageBox.Show("There was a problem login into account.\n Verify that username and password before continuing.");
            }
        }

This post has been edited by tlhIn`toq: 04 August 2012 - 08:30 AM
Reason for edit:: Please use code tags in replies as well as initial post

[tlhIn`toq]

I'm not certain, but this concerns me.

ServerInfo testResult = Json.Deserialize<ServerInfo>(temp2[1].Substring(0, temp2[1].Length - 3).TrimEnd(trimmer).TrimStart(trimmer));
                    server = testResult;

ServerInfo testResult is a method-level variable that will be destroyed at the end of the method.

server is then referenced to this object... that gets destroyed.

It wouldn't surprise me to find out that server becomes null once garbage collection takes place.

It might be wise to .Clone() the object rather than just use the = assignment which on objects is a reference to the existing object, not a duplication of the object.

[toyotajon93]

I didnt write most of the code, just trying to help a friend make improvements. I may be in over my head for my knowledge...

[toyotajon93]

here is my project file if interested.

Sorry I cant do anything right this morning, lol

Attached File(s)

•  Wolffsens Utilities for Emross War1.zip (172.79K)
  Number of downloads: 52

[CodingSup3rnatur@l-360]

MrShoes was spot on with the question regarding the server variable. The problem is that server is null when LogOnToEmross is called, meaning this line; server.server fails as you cannot access a property/field on a null object.

Yes, you instantiate server in the LogOn() method, but you don't call LogOn before you call LogOnToEmross.

I strongly suggest you read and learn from tlhIn`toq's What does this error mean? article. Using the techniques discussed in that article, and the articles about debugging linked from it, I was able to find the problem in under a minute. That's the power of the debugger for you

Also, just to clarify;

Quote

ServerInfo testResult is a method-level variable that will be destroyed at the end of the method.

server is then referenced to this object... that gets destroyed.

It wouldn't surprise me to find out that server becomes null once garbage collection takes place.

that won't be a problem in C#. If Json.Deserialize() returns an reference type, the reference stored in the server variable will keep the object alive on the heap, and only the reference that was stored on the stack or CPU register will be destroyed.

If it returns a value type, the structure will be copied into the server variable's storage location on the heap, and so will still be alive beyond the LogOn() method, and the original copy that would most commonly be on the stack or in CPU registers will be destroyed.

EDIT:

The garbage collector doesn't run at the end of every method, and when it does run, it will only collect objects that don't have any strong references to them

This post has been edited by CodingSup3rnatur@l-360: 04 August 2012 - 12:43 PM
Reason for edit:: I seem to have become confused about when to use quote tags vs code tags

[toyotajon93]

I have it call Logon() in the LogontoEmross() method. Where should I add Logon() to LogonToEmross()? I have tried different locations with no luck.

[CodingSup3rnatur@l-360]

toyotajon93, on 04 August 2012 - 05:54 PM, said:

I have it call Logon() in the LogontoEmross() method.

Yes, but not until after you have accessed server.server, which causes the NullReferenceException.

Quote

Where should I add Logon() to LogonToEmross()?

I have no idea. You (or your friend) have to evaluate what to do. I don't know your application well enough to comment with any accuracy. All I can tell you is that if you want to use server.server, you must give the variable server on the left hand side of the . a none null value first. How you manage that is down to you i'm affraid.

This post has been edited by CodingSup3rnatur@l-360: 04 August 2012 - 11:25 AM

[toyotajon93]

Thank you, this is where I wish I knew c# better. I'll keep playing with it, has me pulling my hair out at the moment....

[toyotajon93]

Thanks to everyone for the help, I have more of a feeling now that I was given decompiled source code. I'm seeing strings like, each like in the return causing a recursive call error.

public static Wolffsens_Utilities_for_Emross_War.Item bronzeKey
        {
            [CompilerGenerated]
            get
            {
                return bronzeKey;
            }
            [CompilerGenerated]
            set
            {
                bronzeKey = value;
            }
        }

In the code and I dont think this is part of the code. I'm not sure how much time I should waste trying to get this up and running since I'm no expert. If anyone has some free time and is bored would love their input. I'm sorry for wasting time thinking it was source.

[JackOfAllTrades]

This looks like a violation of the game's TOS, so I'm nuking this.