Click here to Skip to main content
15,886,110 members
Home / Discussions / C#
   

C#

 
QuestionDrag and Drop Ms-Word,Excel Pin
Member 1370632014-Jun-19 19:45
Member 1370632014-Jun-19 19:45 
AnswerRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
OriginalGriff14-Jun-19 19:58
mveOriginalGriff14-Jun-19 19:58 
GeneralRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
Member 1370632014-Jun-19 21:37
Member 1370632014-Jun-19 21:37 
AnswerRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
OriginalGriff14-Jun-19 21:42
mveOriginalGriff14-Jun-19 21:42 
GeneralRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
Member 1370632014-Jun-19 22:07
Member 1370632014-Jun-19 22:07 
AnswerRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
OriginalGriff14-Jun-19 22:22
mveOriginalGriff14-Jun-19 22:22 
GeneralRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
Member 1370632018-Jun-19 18:30
Member 1370632018-Jun-19 18:30 
GeneralRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
OriginalGriff18-Jun-19 20:08
mveOriginalGriff18-Jun-19 20:08 
Member 13706320 wrote:
Object reference not set to an instance of an object.


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!
Sent from my Amstrad PC 1640
Never throw anything away, Griff
Bad command or file name. Bad, bad command! Sit! Stay! Staaaay...
AntiTwitter: @DalekDave is now a follower!

AnswerRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
Eddy Vluggen15-Jun-19 1:00
professionalEddy Vluggen15-Jun-19 1:00 
GeneralRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
Member 1370632015-Jun-19 1:35
Member 1370632015-Jun-19 1:35 
GeneralRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
Dave Kreskowiak15-Jun-19 5:51
mveDave Kreskowiak15-Jun-19 5:51 
GeneralRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
Member 1370632018-Jun-19 5:46
Member 1370632018-Jun-19 5:46 
GeneralRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
Dave Kreskowiak18-Jun-19 9:24
mveDave Kreskowiak18-Jun-19 9:24 
GeneralRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
Member 1370632018-Jun-19 18:17
Member 1370632018-Jun-19 18:17 
GeneralRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
Dave Kreskowiak19-Jun-19 2:59
mveDave Kreskowiak19-Jun-19 2:59 
AnswerRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
Eddy Vluggen15-Jun-19 1:32
professionalEddy Vluggen15-Jun-19 1:32 
GeneralRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
Member 1370632015-Jun-19 2:33
Member 1370632015-Jun-19 2:33 
GeneralRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
Eddy Vluggen15-Jun-19 2:48
professionalEddy Vluggen15-Jun-19 2:48 
GeneralRe: Drag and Drop Ms-Word,Excel and PowerPoint Pin
Member 1370632015-Jun-19 3:20
Member 1370632015-Jun-19 3:20 
QuestionCatching exceptions in fire&forget tasks Pin
Bernhard Hiller14-Jun-19 2:58
Bernhard Hiller14-Jun-19 2:58 
AnswerRe: Catching exceptions in fire&forget tasks Pin
BillWoodruff14-Jun-19 11:58
professionalBillWoodruff14-Jun-19 11:58 
AnswerRe: Catching exceptions in fire&forget tasks Pin
Eddy Vluggen14-Jun-19 13:37
professionalEddy Vluggen14-Jun-19 13:37 
GeneralRe: Catching exceptions in fire&forget tasks Pin
Bernhard Hiller16-Jun-19 20:49
Bernhard Hiller16-Jun-19 20:49 
QuestionRe: Catching exceptions in fire&forget tasks Pin
Eddy Vluggen16-Jun-19 22:45
professionalEddy Vluggen16-Jun-19 22:45 
AnswerRe: Catching exceptions in fire&forget tasks Pin
Gerry Schmitz14-Jun-19 20:59
mveGerry Schmitz14-Jun-19 20:59 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Praise Praise    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.