error that i gt when i run my application

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Object reference not set to an instance of an object. in Line 68: while (dr.Read()) i do not understand that error please help pple!!!

Posted 19-Sep-12 12:26pm

Fakude23

Updated 19-Sep-12 12:27pm

v2

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Kenneth Haugland 19-Sep-12 18:44pm

Can I se the declaration of dr?

[no name] 19-Sep-12 20:28pm

The error is perfectly clear. You are trying to use an object that is null.

Sergey Alexandrovich Kryukov 20-Sep-12 0:24am

Right, it the line is shown correctly, there is no room for guesswork.
--SA

Rockstar_ 20-Sep-12 0:25am

please assign the dr with some value...

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Sergey Alexandrovich Kryukov · Answer 1 · 2012-09-19T12:49:00

Solution 1

If you are sure that the exception is thrown exactly in that line, it can only mean that dr is equal to null. Check up where this object is constructed and make sure it's not null at the moment of de-referencing; or change the logic of the code to check if (dr != null) … to use it only when it is not null. Always run it under debugger to make sure all object gets appropriate value.

Actually, you should use the debugger whenever you have a slightest concern about your run-time behavior (not only when you have an unexpected exception), and also before you ask a question. Do your homework to get the most from the help you may get.

—SA

Posted 19-Sep-12 12:49pm

Sergey Alexandrovich Kryukov

Updated 19-Sep-12 18:23pm

v3

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CodeHawkz 19-Sep-12 23:59pm

Correct answer :) My 5

Just a small note, you've used '==', it should be '=' :)

Sergey Alexandrovich Kryukov 20-Sep-12 0:22am

Thank you very much.
No, I meant "==", not "=". This is not a part of the code, but the part of statement meaning "that dr is equal to null". Well, to avoid confusion, I'll replace it with words...
--SA

CodeHawkz 20-Sep-12 0:45am

hehe, I got it but thought others might not, that's why :)

Sergey Alexandrovich Kryukov 20-Sep-12 0:47am

Reflection can cause the avalanche effect; did you think about it?
--SA

CodeHawkz 20-Sep-12 1:02am

agreed :)