delphi - Why would you check for Assigned(self) in object methods? -

-

I'm looking at some code (Delphi 7) with which the following check is at the top of each method call for a specific object : 

  If not assigned (self) then take exception. CreateRes (@sAbstractError); {The actual code for this method}

I think it will stop me from trying to call a method on an empty object pointer. But as soon as I am in the case of member data Tried to reach, I will get an exception, is not it?

Is this some type of standard that I have never seen before? The object in question arises from TPersistent.

You can call an example method on an empty pointer, though it is not something that you knowingly When this happens, the execution continues to a great extent until it needs to reach the frequency data and then it all gets banged.

In that case, will alert you to the top of the screening process for zero, so that you do something different as a stack trace logging or you can put a break point on the lifting line so that you can enter it Can and see what is happening.

Ie, there was something that I could do if I had a specific bug that I was trying to track down, a zero reference was being used

It regularly kills me as a code odor.


Comments

Post a Comment

Popular posts from this blog

c++ - Linux and clipboard -

-
After selecting the copies of the buffer in Linux, after the text, we can click and paste the button between the mouse. I think there is a special buffer for this, I want to use it. Programming Language: C ++ Your Library: Qt Thanks. There is just one more correct answer than Paul Dixon, which answers your needs: / P > QClipboard * clipboard = QApplication :: clipboard (); CastString Selected Text = Clipboard-> Text (QClipboard :: Selection);
Read more

Visual Studio 2005: How to speed up builds when a VSMDI is open? -

-
Using Visual Studio 2005, if I open the test in VSMFI and try to run the tests, then sometimes the projects are ready. However, they run very slow. CPU 99% waste and output window VS Shows things associated with compiling it. Is there any way to fix this? It does not make any sense. It is not necessary to upgrade that we are a viable alternative to those people who have to deal with the legacy code. Did you try to upgrade SP1? I do not know of any specific problem in this area, but this will be the first change I tried to do.
Read more

booting ubuntu from usb using virtualbox -

-
I am trying to install Ubuntu on a USB, the problem is that I do not want to repeat the boot once, I want to keep my windows, but I want to boot Ubuntu using the virtualbox and USB to the Ubuntu Want to use my hard drive, but how? The virtualbox will not recognize USB as a hard drive when installing an ISO In virtualbox, you have to create a virtual hard disk. Make a USB drive and tell the virtual box to install a virtual hard drive that you just created. EDIT: To answer some more questions: In the new Virtual Disk dialog, click the button next to the location field, click on the button Virtual Disk on Flash Drive To access, click the arrow next to Save in the Select File in the window next to Save In, and you can access your flash drive from there. I recommend setting the image to be allocated dynamically, because the size of your flash drive is not available disk space. I name the image, then select that image to install Ubuntu in the Verbill box. The virtualbox will never
Read more