I have an old program that was made for us a looong time ago. It consists of a large MDB (Access) file with all the data (no encryption, I can manually open the file and browse all the data) and an EXE file (probably VB?) that was custom made to easily manage the data in the file.
I'm trying to move this program for another user, to run in his own laptop.
First I tried just copying all the files, but I had MSCOM, GRD, LST, and ocx missing file errors. I tracked them all down and regsvr32'd them, and the program seemed to go a little further.
Then I got an ODBC connector error. Playing with ODBC sources manager and I added an entry with the name of the program that points to the specific MBD file. This helped too.
Now program starts and shows all menus, buttons and everything. However, the default record that should be onscreen is empty and as soon as I hit any control (next record, list, etc...) it crashes with a VB error 91:
Run-time Error '91': Object variable or With block variable not set
So it looks like the program can open the database file itself but it cant really access the data inside.
What else can I try to see what I need to set it all up correctly? Is there anything that "spies" inside and VB program to see how it's trying to access the MDB file?
Any help would be appreciated!
Probable cause of your problem is some missing dll/ocx file referenced in your application. Open your exe file with notepad (or notepad++) and find all occurrences of .dll and .ocx files and check if those
files exist at user's laptop. If not, just copy them from your working machine and regsvr32 them.
I will go with #smith suggestion.
While looking at the error message on microsoft's website, below is the solution that applies to your scenerio
"The object is a valid object, but it wasn't set because the object library in which it is described hasn't been selected in the Add References dialog box."
So ensure all files are correctly copied to new system.
Related
So the images below were originally a vb files. I have just opened it and it looks like this and the compiler won't run it. I am unsure whether this is a compiler error or whether it may have become corrupt because the project is stored on an external drive. It is just these two forms that have broken like this; I have one other form and a module in the same project that are okay but the project can't run because of the two that are broke.
Broken Login Form
Broken Diary Form
If it changes anything, the designer files for the forms are intact it is just the scripting for the forms elements that is broken.
Also, if I can't identify the cause, is there a way to revert it back to the last working version in visual studio to get my code back? Just because I put a lot of time into it.
The data in those files is most likely gone.
IMPORTANT: Do not write anything to that disk drive unless you find that you cannot recover those files.
If you are using a version control system then you can revert to an earlier version.
If you are using Windows 10 and you happen to have stored those files in a location included in what File History saves, you can recover them from that.
If you use some other form of backup, retrieve the files from that.
If you have a separate disk drive with at least as much free space as the one with the corrupted files, you could try running file recovery software as it might be that the zeroed-out file was written to a different place on the HDD.
TinTnMn pointed out in a comment that if you previously compiled the code, you should have executable files in the "obj" and "bin" folders that can be decompiled to recover most of your work
It could be quicker to re-write the code while it is still fresh in your mind.
I'm in the process of building a program that has several external libraries and extensions outside of the main program files. My projects total size is 134.2 MB. I would like to make a portable version of it with Turbo Studio, but I face one glaring problem; After capturing the files and building the project I'm left with a 138.9MB executable. The program does run, but I don't want it to be so bloated.
I would like to bundle the bulk of the data as a separate .dat payload (or equivalent) but I can't seem to find any means of doing this with Turbo Studio. VMware ThinApp and Cameyo both do this automatically after the project exceeds a certain size, but it would appear that Turbo Studio doesn't.
Any help with is greatly appreciated.
There was a hack I had discovered some time ago that did exactly what you were asking.
It appears that the site that described it is not online anymore so read on.
Install your application while monitoring with TurboStudio.
If there are multiple entry points (e.g., a suite like office may have
shortcuts for excel, word etc) then make sure there are shortcuts for those entry points in the Start Menu. If there are not, then click Start, right click on All Programs, then Open All Users. Make sure you create in that folder shortcuts for all your desired entry points (e.g., one shortcut for word, one for excel etc.)
Capture and Diff with TurboStudio. Set your virtualization settings as desired.
Click Output File-->Browse, and select "All files(.)" in the Save as type list. Then enter a filename with the extension .dat
Build your app. You will now get a .dat file instead of an .exe
In the next step you must use ExeBuilder.exe. This file was originally hosted in csgotwisted.com. Do a google search for "2 utilities for spoon studio exebuilder" and it will most likely be the first result. Unfortunately, the link is dead now when I click it. So I uploaded the file to NitroFlare. You can find it here. Put it in the same folder as the .dat file and run it. It will create a shortcut with your executable. Sometimes it misses the icon, but it gives you the option to locate it manually.
I use TurboStudio often and I have found this way to be the most quick and reliable in allowing me to generate small executables and storing the virtual filesystem and registry in a .dat file. In addition, it has the advantage that it can get you multiple entry points and not only one, just like Thinapp does.
I'm making a simple VB.net application, which basically asks the user for multiple files and later it will need to access the selected files and modify them.
Right now, I'm saving the full paths of the selected files, and in the future, the application will iterate through each path, open the file from such path, and modify it.
The problem with that is that the user could select a file (so the full path is saved) and then they delete or move the file before my application modifies it.
Normally, I'd throw an error saying "File not found", but I'm under the impression that Windows had a feature that would disallow you from deleting/moving/renaming a file because "a program was using it" - which is a feature that would fit way better for my application.
I'm not very advanced with VB.NET, but I suppose that if I "open" a file using my application (with some IO thing), the feature I mentioned earlier would indeed trigger and the user would be unable to modify the file because it is "opened" by my application.
However, since my only desire is to "reserve" files, it seems to be quite wasteful to actually open them when I don't really need to (yet). Is there a way to tell Windows I need a certain file to be intact?
Opening files (with specifying desired sharing mode) is the way to do that.
I don't believe there is anything really wrong with opening multiple files (also you still will not be able to do anything for cases like removing of removable drive). In old times there were restrictions on number of opened files per process, but I it no longer practical limitation - Pushing the Limits of Windows: Handles
There is an easy solution: open each file in exclusive mode.
It should look like this:
Sub test()
Dim FS = System.IO.File.Open("path", IO.FileMode.Open, IO.FileAccess.ReadWrite, IO.FileShare.None)
End Sub
But beware: You have opened a file handle and if you code responsible for closing files fails without terminating the application files will still be locked for very long (till app shuts down).
You can use a using clause or a try/catch/finally clause - I don't know enough about your program to recommend anyone.
In the system32 directory I saw an .OCX file with a corresponding .OCA file.
I had thought .OCA files are used only by Visual Basic. Are they therefore unnecessary for program execution and could be removed?
If they are unnecessary, why would there be an .OCA in the system32 folder in the first place?
.OCA files serve as a cache of the extended type library information for its corresponding .OCX file.
If you delete an .OCA file for a control VB recognizes and uses, VB will recreate the .OCA file when you load a project requiring the control. The recreation process takes a little time but comes with no penalty otherwise.
Last reviewed: April 4, 1996
Article ID: Q149429
SUMMARY For every custom control file (.OCX) that Visual Basic uses,
there is an accompanying .OCA file of the same file name. For example,
GRAPH16.OCX has an accompanying .OCA file called GRAPH16.OCA. An .OCA
file is a binary file that functions as both an extended type library
file and a cache for the custom control file.
MORE INFORMATION
A type library is a file or component within another
file that contains OLE Automation standard descriptions of exposed
objects, properties, and methods. The actual working type library for
a custom control used in Visual Basic is a combination of the type
library of the control itself and the additional properties provided
by the framework that wrap the control.
Some of the properties of the control are provided by the framework
and some by the control itself. Programmatically, the properties from
the framework and the control all appear as properties of the control.
In order for these properties to appear, Visual Basic creates an
extended type library when the control is loaded into the toolbox.
Because the process of reading the control's type library and creating
the extended type library is time consuming, Visual Basic caches the
extended type library information into an OCA file.
If you delete the OCA file for a control Visual Basic recognized,
Visual Basic will re-create the .OCA file when you load a project
requiring the control. This re-creation process comes with a time
penalty.
(http://support.microsoft.com/kb/149429)
So, don't worry about including them when you deploy your application.
Sorry to resurrect a zombie thread, but I want to summarize to make sure I understand this.
An OCA file is only needed during compilation of a program and if it is missing, VB will create what it needs so all that is lost is time during compiling. Unless you have really sloppy programming and another homemade dll or ocx needs a particular oca.
If an oca is shipped with a product, it should be able to be safely deleted.
No, they are not necessary for it to execute but they are necessary for the program to run properly (if the program required the file in the first place).
They never need to be deployed with a finished program for it to run.
This could be a dumb attempt to answer, but you could simply rename the file and see if the application quits working. If so, those files are necessairy.
DNA-science is about the same:
Remove a gene and see what stopped "working". De facto, this gene is related to / necessairy for that body-part or whatever.
Re: No, they are not necessary for it to execute but they are necessary for the program to run properly (if the program required the file in the first place).
Since execute and run mean the same thing - what you are saying is that:
it's not required for it to run but it's required for it to run properly??
or alternately
it's not required for it to execute but it's required for it to execute properly??
I am suspecting that the *.OCA files are not required EXCEPT for compiling a program using VB and if they don't exist when you load a project then VB will create any missing OCA files automatically in order to speed up future load or compile operations in VB.
I just deleted EVERY OCA file off my system (I'm a brave man when I'm using a cloned virtual machine to do this).
I then rebooted and ran my software and it worked just fine without ANY OCA files on my entire system. Now it might take a bit longer to load/compile my programs next time as vb will regenerate the OCA files but I'm using an i7 with 16Gb of RAM and an SSD so who cares!
I have a Windows service application on Vista SP1 and I've found that users are renaming its executable file (while it's running) and then rebooting, thus causing it to fail to start on next bootup because the service manager can no longer find the exe file since it's been renamed.
I seem to recall that with older versions of Windows you couldn't do this because the OS placed a lock on the file. Even with Vista SP1 I still cannot copy over the existing file when it's running - Windows reports that the file is in use - makes sense. So why should I be allowed to rename it? What happens if Windows needs to page in a new code page from the exe but the file has been renamed since it was started? I ran Process Monitor while renaming the exe file, etc, but Process Mon didn't report anything strange and just logged changing the filename like any other file.
Does anyone know what's going on here behind the scenes? It's seem counter intuitive that Windows would allow a running process' filename (or its dependent DLLs) to be changed. What am I missing here?
your concept is wrong ... the filename is not the center of the file-io universe ... the handle to the open file is. the file is not moved to a different section of disk when you rename it, it's still in the same place and the part of the disk the internal data structure for the open file is still pointing to the same place. bottom line is that your observations are correct. you can rename a running program without causing problems. you can create a new file with the same name as the running program once you've renamed it. this is actually useful behavior if you want to update software while the software is running.
As long as the file is still there, Windows can still read from it - it's the underlying file that matters, not its name.
I can happily rename running executables on my XP machine.
The OS keeps an open handle to the .exe file,. Renaming the file simply changes some filesystem metadata about the file, without invalidating open handles. So when the OS goes to page in more code, it just uses the file handle it already has open.
Replacing the file (writing over its contents) is another matter entirely, and I'm guessing the OS opens with the FILE_SHARE_WRITE flag unset, so no other processes can write to the .exe file.
Might be a stupid question but, why do users have access to rename the file if they are not suppose to rename the file? But yeah, it's allowed because, as the good answers point out, the open handle to the file isn't lost until the application exits. And there are some uses for it as well, even though I'm not convinced updating an application by renaming its file is a good practice.
You might consider having your service listen to changes to the directory that your service is installed in. If it detects a rename, then it could rename itself back to what it's supposed to be.
There are two aspects to the notion of file here:
The data on the disk - that's the actual file.
The file-name (could be several or none) which you can give that data - called directory entries.
What you are renaming is the directory entry, which still references the same data. Windows doesn't care about your doing so, as it still can access the data when it needs to. The running process is mapped to the data, not the name.