Web Crawler - object not found [duplicate] - c#

This question already has answers here:
What is a NullReferenceException, and how do I fix it?
(27 answers)
Closed 9 years ago.
I am developing a web crawler in asp.net.
My web-crawler has a main page from which it opens other HTML pages from HREF tags, downloads the HTML page and fetches the data.
The problem now is sometimes I get an exception of object reference not found sometimes the code works perfectly.
Is it because the asp.net buffer memory is full? If you want I can show you my code.

You will need to debug your code. There is some code of your project or some library you are using that is not right checking if a object is null before using it.
Try this:
On Visual Studio
On the Debug menu, click Exceptions.
In the Exceptions dialog box, select Thrown for 'Common Language Runtime Exceptions'.
Start debugging (F5).
When the exception is throw, VS will break and it will show what is the possible code line with the problem.
More in How to: Break When an Exception is Thrown

Related

What is the meaning of the runtime error - internal CLR error 0x80131506 [duplicate]

This question already has answers here:
Troubleshooting .NET "Fatal Execution Engine Error"
(5 answers)
Closed 3 months ago.
While I was debugging a simple bit of C#. I got the error 'internal clr error 0x80131506' and the program being debugged crashed. It's .NET Core 3.1 running on Windows 10 x64.
The code wasn't doing much interesting, just calling a method that iterates an array, from another static method in a class, ultimately called by a console application Main method.
I'd be interested to know if there is some way to look up these types of error codes, I couldn't find anything in my search - but perhaps I'm not searching for the correct thing, so any pointers would be appreciated.
After YEARS of using Unity, I finally got this error.
Similar to a lot of other weird and unexplainable errors.
When in doubt, reboot!
Deleted Library folder and rebuilt it - problem gone!

Unknown message while debugging in Visual Studio 2012 [duplicate]

This question already has answers here:
Your step-into request resulted in an automatic step-over of a property or operator
(9 answers)
Closed 8 years ago.
Today while i was debugging my code step by step i encountered one message while debugging my ASP.net web api.
I had never encountered any such message. What is this message and why it came, what is the main purpose of it. Can anybody explain.
Visual Studio is asking that its going to skip some code and debug your program. And this message is to ask that do you need to be informed whenever this happens.
If you want to be informed in future, you can select "Yes" otherwise select "No"
You can simply ignore this and continue.

Object reference not set to an instance of an object with no error line [duplicate]

This question already has answers here:
What is a NullReferenceException, and how do I fix it?
(27 answers)
Closed 8 years ago.
I know that it is a wrong type of question but I have been tired...
I have sent the published files to the customer and now they say they have an error. They printed the error for me. It is something like this:
It is an intranet application and does not have any problem in my local and because of security reason I can not remote to their server.
What is your suggestions...
Any help...
The exception means some object is null and you try to access one of it's properties or methods.
The exception is thrown from ReportSection method from SiteMaster class, you can put your .pdb files beside your dll to get the line number too.
If want error line to be printed in your Error stack trace than you have to include .pdb file.
Pdb file generally contains debugging information used by the debugger.
So you have to put .pdb file along with .dll file to get more debugging information.

How do I remove the debug string in the windows emulator? [duplicate]

This question already has an answer here:
Closed 10 years ago.
Possible Duplicate:
WP7 RTM Emulator is displaying the framecounter and dx info on the rightside - is this the default?
I want to take a nice screenshot of my app and send to a friend, but I got the silly debug string in the upper right corner. How to I remove it?
Seems to be numbers and shift if using acceleration for instance
Try running it as non-debug as you can:
Use a release build instead of a debug build
Use Ctrl-F5 instead of F5 to launch (so there's no debugger attached)
IIRC, that will prevent the diagnostic information from showing. It's probably that you only need to take one of these steps, but I couldn't tell you which offhand.

Catching First Chance Exceptions in Managed Code without being debugged [duplicate]

This question already has answers here:
Is there a way to log or intercept First Chance Exceptions
(3 answers)
Closed 5 years ago.
Is there a way to catch First-Chance exceptions, and log them without running under a debugger?
I suppose another way to ask the question is can I write something that will act like a debugger being attached to my process and see what is going wrong while it happens?
If you are on .NET 4.0, you can use theAppDomain.FirstChanceExceptionevent to get notification of exceptions.

Categories