My Delphi 2010 is sick

[WojTec]

So, I have custom constructor, I'm setting components in this constructor, all what happen later depend on these settings - and working, till I add this check box or combo box (I tried both).

For example I'm drawing gradient, in method I'm using cbPath.Checked - working.
When I add this condition then stop working

Code:

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Debugger Exception Notification
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Project x.exe raised exception class EAccessViolation with message 'Access violation at address 0062DCF7 in module 'x.exe'. Read of address 00000000'.
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Break   Continue   Help   
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Code:

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Debugger Exception Notification
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Project x.exe raised exception class EReadError with message 'Error reading edtSteps.SpinOptions.MinValue: Access violation at address 0062DCF7 in module 'x.exe'. Read of address 00000000'.
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Break   Continue   Help   
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This behaviour is completely nonesense for me...

[himitsu]

address 00000xxx = nil

Something does not exist.

Zitat von Sailor:

Probably cbPath has not yet been created. Check it by adding "IF cbPath <> NIL" to the first line.

or if not Assigned(cbPath) then DoError; , Assert(Assigned(cbPath)); , Assert(cbPath <> nil); , ...

[WojTec]

@himitsu, you are talking about first or second address in message?

Let's say Delphi creates it incorrectly (I repeat: error after changes, before working) - what to do?

[mkinzler]

The second. The First is the adress of the Code itself.

[WojTec]

Ok. So, what to do now?

[mkinzler]

cbPath references not an existing Object. It seems that it is never set at all ( 0 = nil = nirvana)
Check if/where you set that variable.

[Stevie]

Your dfm file does not match the pas file.

When loading the form it streams the dfm file and creates the components and places the references in the published fields if they exist (yes, you can have a component on your form but no field in your pas file, if you don't need to access it). But it does not work the other way around. If you placed your component field in the published part (which is by default if you dont specify the visibility) but never created it yourself.

Usually the IDE also complains about this when saving your form (like "Field Form1.CheckBox1 does not have a corresponding component. Remove the declaration?")

Also: did you call inherited in your custom constructor?