VB.NET Opening A File From Form - vb.net

I'm using the following the code to open a file that resides elsewhere on the computer:
System.Diagnostics.Process.Start(PathToOpen)
Where PathToOpen is the full address to the file I wish to open. This appears to work as intended for any file type that has an application installed that can open the file.
Whilst this works OK, if the file is on a networked drive, I want my VB.Net code to check if the file is currently in use, if so display a message. Currently what happens is if a second user tries to open the file, it opens read-only (a word file for example) which is handled outside of my application. I want to intercept before the file is opened and stop the process there.
Is this possible at all?

You are basically asking if it's possible to monitor files on a system that doesn't even belong to you ?
Word does know about a file already in use because it creates a hidden file next to the one you open. if there is already a hidden file, it means the file is already in use.
Other applications use different ways of knowing if a file they can use is already opened somewhere else.
In order to do what you want to do, you need to know how all the applications handle this problem...
A possible solution would be for you to create a small hidden file next to the file the user wants to open (just like MS Word does). Only problem, you need to destroy the file when it's closed by the user, and you have no way of knowing that...

Related

Excel on Mac. Cannot open IQY file in Data/Get External Data/Run Web Query

I am running Excel version 16.45 on Mac.
I have created a .iqy and saved it in the Queries directory alongside certain templates which were already there.
I go to Data/Get External Data/Run Web Queries. While the templates are accessible, my file is visible but greyed out (same thing happens if I save the file in a different directory).
Would anyone be able to help?
According to your information, I would like to confirm whether the issue occurs when you follow the steps as below:
1.Create a Word file, paste the web URL.
2.Save the Word as .iqy with .txt format.
3.Choose MS-DOS as coding.
4.Create an Excel file and click "Data >Get External Data >Run Web Query (Or Run Saved Query) " of the Bar
I was able to address the issue as follows.
When navigating to the relevant directory with Finder, the '.iqy' file appears to be appropriately named (as per Image 1).
In fact, if you reach the file in Terminal, the file is saved as '.iqy.txt'.
So all I had to do is rename the file, simply removing the '.txt' string at the end.
Screen you see when navigating in Finder

I want to copy the file in sandbox without NSOpenPanel

I want to copy some files to specified folder by NSOpemPanel.
The source file is reading from XML and show to list in NSTable.
I can copy file by copyItemAtPath.
But now my app will turn to sandbox, then I can’t copy the file by copyItemAtURL.
How do I copy the file in sandbox mode?
I was looked over a lot of post. And I think the Security-scoped Bookmark may be a solution for this.
But I can’t create "Security-scoped Bookmark" from XML inside the path (the path was convert to NSURL ready).
I was setting to sandbox.entitlements but it's not clear this problem.
Is there any way for this?
Develop in macOS10.12 and Xcode8.3.3
Thanks
How do I copy the file in sandbox mode?
It is unclear what your current code is doing, but the rules under the sandbox are simple: To read or write a file located outside of an application's own container (which is hidden away under the Library folder) your application must either:
Use NSOpenPanel to obtain a URL from the user for the file path; or
Use NSOpenPanel to obtain a URL from the user for one of the ancestor folders of the file.
The second option gives access to a whole folder, including any sub-folders; i.e. the whole file/folder subtree rooted in the folder.
As you want to copy "some files" it sounds like asking the user for permission for the folder is appropriate. You can customise the NSOpenPanel to be a "request permission" dialog. If you are requesting a specific folder you can also have the dialog open in it's containing folder and only have the specific folder enabled for selection by the user.
Once you have the URL for the folder from NSOpenPanel you can create a security scoped bookmark for it and save that in your app's preferences or other configuration file (stored within the app's container). Doing this enables your app to regain access to the folder on subsequent executions without asking the user again.
If after investigating this issue and writing some code you hit an issue ask a new question, showing your code, and explaining the problem. Someone will undoubtedly help you with the next step.
HTH

errors when opening file - it is opening as read only

Having a few issues when opening an external excel file.
Basically we have a system where we use a template excel file that writes to another excel workbook. (Multiple users could be in a template file at any one time)
The code is pretty straight forward in that it opens the file as readonly when extracting information and it opens the file as normal when adding/updating new information.
An issue has arose though with 1 particular user - when they click the button to update it always opens the file as read only (doesn't happen to anyone else) I have tried putting her on a different PC and it worked fine - so I am thinking it must be something to do with her settings on our system.
As anyone else come across this or any ideas how to resolve? (Done a office repair but didn't help)
Thanks

Problems overwriting file in application folder

I have a file called PolicyLookup.sql that sits in my application's root folder. My app loads this file into a text box, so that users can edit it and overwrite the original file by pressing a save button. This all worked perfectly during test, however after deployment users are unable to save the file due to write issues within C:\Program Files.
Is there a way around this - or is there a better way to implement this type of thing? One solution that springs to mind for me is placing the contents of the PolicyLookup.sql file within a User Setting - however it intrinsically feels wrong to me to put the entire contents of a file within a settings variable.
Ordinary users do not have write permissions on %ProgramFiles%. If you need to save a configuration file then put it in a subfolder of %APPDATA% (which for me is C:\Users\Gord\AppData\Roaming) or some other place where a regular user is allowed to write.

VB Open file then disallow access

My program will have to be run on different computers at the same time in the future. How can I open the file when my app loads up, then deny access to anything else EXCEPT the current instance of my app? (first come first serve for access to the file).
Or a way to just flag the file in a particular way and I can run a check on Form Load to see if it is flagged or not and pseudo-lock it by just disabling any button that triggers interactions with the file.
This is just to prevent more than one person from working with the same file at once.
Basically any method to allow this will be fine. I just need a starting point and I can tweak and optimize as I go on.
You can open the file with the File.Open and pass in FileShare.None as your sharing type. This will restrict others from opening the file.
File.Open(path, FileMode.Open, FileAccess.Read, FileShare.None)
Edit:
Just guessing from some of your other questions that you are calling XElement.Load on this file later in your application. One of the overload for Load takes a Stream. The File.Open method returns you a FileStream. You could just open the file immediately on application open, and then when you are ready to read the XML file, just pass the FileStream into XElement.Load.