Visual Studio crashes when opening PDF for second time - c#

I have a bit of a strange problem, in my program, when I open a PDF file using the following command:
Process.Start("test.pdf");
the first time, the file is opened just fine, but the second time I use this command on ANY pdf file, at ANY position in the code, vshost.exe crashes.
My next step was to disable vshost, with vshost disabled, the application its self crashes.
When I say 'crashes' I mean it says that it has stopped responding.
If I create a new project, it works just fine, so it must be something wrong with my project?
I am using the iTextSharp library at other points in the code to create the pdfs, could this be a cause?
I realise this problem is very general but I have no idea what could be causing it so I dont know what information to provide.
More info:
When I look at the output of the debugger after the program crashes it says "The program '[4320] SmartShelf.exe: Managed (v4.0.30319)' has exited with code -1073741819 (0xc0000005) 'Access violation'."
Edit: Does anybody know any other way of viewing a pdf using c#?

I would use using context or the dispose command to get rid of any open file connections before calling the start("asdf.pdf") and see if that takes care of it.
Also make sure your process is running as admin in win7.
And another thing you can try is use process.start(cmd, "aspdf.pdf") this way your starting a command window and it calls the pdf starter.

Although not perfect, my solution in the end was to display the pdf in a webBrowser control, by setting the URL to the path of the PDF using
webBrowser1.Navigate("asdf.pdf");
this displayed it in adobe reader but within a web browser.
This solution suited my needs absolutely fine (if not better) and doesn't cause the application to crash. Thanks for everybody's suggestions.

Related

Process.Start() exits right away on Windows 7

Process.Start("d:/test.txt"); //simple .txt file works perfectly fine on Windows 8 onward but on Windows 7 (x64) it starts the process and immediately closes it.
I've already tried the following:
Calling through ProcessStartInfo and setting CreateNoWindow=true, UseShellExecute=true and Verb="runas" (though not sure why I had to set this one).
Tried attaching Exit event and it confirms that the process does start but it exits right away and I don't even see the Notepad window open for a blink of a second.
Edit: I've tried it with an image files and few other extensions and they open just perfect. Something wrong with just the .txt files (and/or probably other formats).
I was able to solve this bug just by changing build platform from AnyCPU to specifically x64 (my target machine is x64). This is strange but it solved the problem! Thanks Simon Mourier for this tip.
Its definitely an issue with file association. I have tried it windows 7 and it works fine. Try double clicking on the file and check if it opens in notepad, if it doesn't then configure it to open via notepad.Also you should check the exception that it throws,
If File association is missing then it will launch the Openwith dialog.
If it is associated with wrong program then you can change it manually.
If you want to find association type pragmatically then, I would suggest looking at this answer.
How to I get file type information....
You're saying your code is working fine in other OS and other file formats even in Win 7.
Let's try following checks to verify if things are correct
Verify if notepad.exe is in path
Start -> Run -> notepad.exe should launch Notepad
Double click on a .txt file and see if it automatically opens in Notepad
Verify if Process.Start("notepad.exe") starts an instance of Notepad
var process = Process.Start(file used in step 2); and verify the returned process info in the debug mode and see if says the newly created process is still running or not.
I've had this happen on Windows 7 before. It's likely that your Path environment variable has become corrupted. The maximum number of characters that can be used in the Path variable is 2047. Installing many executables on your machine can overflow the Path variable. Here is a SO discussion that shows some ideas to get around it:
How do you avoid over-populating the PATH Environment Variable in Windows?
If you just need to get notepad running again quickly, you can modify the Path environment variable and just put the system location to Notepad at the beginning of the variable. (ex. "c:\windows\system32\notepad.exe").
And if you're not sure how to modify your Path variable, here is a good how-to:
http://geekswithblogs.net/renso/archive/2009/10/21/how-to-set-the-windows-path-in-windows-7.aspx
What about just using
Process.start("start", "d:\\test.txt")
or
Process.start("explorer", "d:\\test.txt")
or
Process.start("cmd", "/c notepad.exe d:\\test.txt")
If it still doesn't work, try using the straight shellexecute, as described here
Executing another program from C#, do I need to parse the "command line" from registry myself?
https://www.gamedev.net/topic/310631-shellexecuteex-api-call-in-c/

Difference in behavior between ProcessInfo/Process.Start and the Run prompt

I'm trying to open a PDF from within my application. I've gone through several iterations for this and have resolved that my only remaining option is to just open Adobe Reader passing the location of the PDF as an argument. The libraries I've looked at don't support what I need (rendering form fields) nor does the Telerik PDF control. So, I've absolutely explored the buy option over build.
Anyway, this works fine from the Run prompt like so:
"C:\Program Files (x86)\Adobe\Reader 11.0\Reader\AcroRd32.exe" "C:\Users\Foo\AppData\Local\Temp\Bar.pdf"
However, from code, doing the following does NOT work:
ProcessStartInfo info = new ProcessStartInfo(#"C:\Program Files (x86)\Adobe\Reader 11.0\Reader\AcroRd32.exe", location);
Process.Start(info);
Using Process.Start, I can see the Adobe process in my Task Manager list as a background process but there is no UI while it works flawlessly from Run where it shows up under App and gives the UI as I'd expect.
I don't see a way to force a UI to appear. The MainWindowHandle is 0, the WindowStyle is set to Normal, and CreateNoWindow is false.
Other things I've tried is setting the EnvironmentVariables collection manually and turning off shell execution. I've also tried loading the user profile into the process to no effect.
What do I need to do do here?
I ended up getting around this situation entirely. I used iTextSharp to flatten the PDF and from there my normal tooling for rendering PDFs worked fine. Thankfully, this has other benefits for my needs as well.
I still couldn't solve the different in behavior I described. I was about to go down the path of Win32 via ShellExecute to leave a "where I left off" note.
*.Pdf files are always opened using Adobe reader, unless you have installed some other pdf reader. So don't call the adobe application, just call the file using Process.start(#"file location and name.pdf"). Then the file will be opened in the default pdf reader.
You'll need a system reference using System.Diagnostics;
And here's another thing, above you have used Process.Start() to give the file location but remember this won't help if the application mentioned doesn't take any arguments/instructions.
Process.Start(#"application.exe", "instructions to application.exe")

c# Programme Error

Unable to copy file "obj\Debug\FootballLeague.exe" to "bin\Debug\FootballLeague.exe". The process cannot access the file 'bin\Debug\FootballLeague.exe' because it is being used by another process.
I got this problem and I couldnt find any another process.Other c# programmes are working properly.I changed the place which I haved saved first time, but I couldnt get any clue to find the error.
Chances are the other process is FootballLeague.exe - are you sure you aren't still running it?
Another alternative is to use Process Explorer to find out what's got a handle on the file.
If your FootballLeague.exe has been launched and is still running, it is the process that is locking the file.
Do you have a virus scanner turned on? They tend to open files for exclusive access at just the wrong time. I would advise that you turn off real-time scanning in your project directory at a minimum.
Other than that, you'll want to use something like Process Explorer to find out who actually has the file open.

c# program works from cmd prompt but not run separately?

I would post a snippet, but I honestly have no idea what part of my code could possibly be doing this. The program is sizable, I don't want to make you all wade through it. What kinds of things could possibly be the cause of this? Everything works perfectly when called from the command prompt: "readoo.exe". But when I click the exe in its file. . . "readoo.exe has encountered a problem and needs to close. . ."
this is intended to eventually be a scheduled task -> i'm worried, will it work?
i've never debugged, all i've ever used is notepad. I am learning, and feel that this strengthens my understanding of a project.
it crashes nearly immediately. there are no shortcuts, though the file paths are relative.
trying this method: shortcut -> properties -> shortcut -> Start In. I don't have a "shortcut" option
my program reads log files, parses, and creates 4 new files based on the found content
Microsoft Error Report says file not found. But how can this be? the files are there, albeit relative.
Take a copy of your project, and then start hacking bits out of it. When it no longer crashes, you've removed the bit causing the problem.
At what point does it fail when you double-click on it? Immediately, or only when you take a certain action?
You could also add a lot of logging to it, which could indicate where the problem is too.
This is probably looking for a dll that it can't find or is finding a different version from what it wants.
You could try Process Monitor or Process Explorer from sysinternals to see what dlls it loads when it does work and where it finds them.
Try putting a System.Diagnostics.Debugger.Break()call as the first thing in Main() and you'll be asked to attach a debugger - this should definitely show you what is different betweent the 2 invocations.
I would start with identifying what is different in the two methods of execution. Is there a shortcut modifying anything?
The starting directory?
The execution account?
command line arguments?
There are 2 things that it could be:
The current directory could be different when you click on the program or run from the command prompt.
The settings and path could be different when you click on the programe you are using the standard command prompt, are you opening the visual studio command prompt when you run the program from the prompt.
If your application relies on some file that should be on the same path of that exe, that can occurr.
You will have to change the properties of the exe (or shortcut to the exe) to "Start In" the directory where your exe is. For a shortcut, right click on the shortcut -> properties -> shortcut -> Start In.
I guess that is what I think could be the cause.
EDIT: Add a Console.ReadLine towards the end of your code to make it pause for you to see any exception thrown. That should help when you run it using windows explorer.
Put a try/catch around your code and output the exception message to the console in the catch block. That should give you some clues.

Reading a Bitmap from a TIF file - Works in WinForms not in ASP.NET

EDIT Solution Found: See my post below.
We are writing a library that reads in a TIF file from a scanner. Basically, its a scantron. We are examining the form and reading values from it.
Currently we have a windows test app, and we give it a filepath as a string ("c:\testing\image.tif"). It loads up the tif, reads the document correctly and parses the values.
We also have an ASP.NET web application. We have a test page that does exactly what the windows app does, we hand it an identical string, and i calls the same function on the same class from the same library. It however does NOT read the form correctly. We have verified that it does it fact load up the tif file, and it is actually filled with data (pixels we expect to be white/black are white/black when we examine the Bitmap obect in the immediate window of Visual Studio).
The specific problem is in a library called DataMatrix we use to scan a bar-code off the document. This function is supposed to return a List<string>, each of which is a barcode the library found on the document. In the windows app, this function (DataMatrixDecoder.DecodeBarcode(bitmap)) correctly returns with a Count=1. When using the asp.net app, this returns with Count=0.
Because its the exact same image file, I cannot imagine the problem is in DataMatrix. I can only assume its something with ASP.NET or something.
This isn't even my project, but another guy and I are helping our coworker figure this out, and we are just pulling our hair out. All signs indicate that ASP.NET is correctly loading and handing the image off disk to the "processor" class (which is a class library that uses the DataMatrix stuff, we are not doing ANY code in ASP.NET except for opening/handing the file to the function.).
Does anyone have any ideas as to what it might be, or different things we can check?
I'm not even sure what kind of information to give so I tried to say it all, if you have any questions please ask I'd be more than happy to elaborate on anything. Thanks.
edit:
this is the code on the ascx.cs code-behind, in a button-click event:
if (formReader.ReadTIFF(#"c:\testing\image.tif"))
{
messages.Controls.Add(HtmlHelper.DivSuccess("Read successful."));
}
The formReader class then open the file with a FileStream, and uses that to create a Bitmap. The ASP.NET application is not actually opening the file at all (we were uploading it through a FormUpload control, but after experiencing problems we dummied it down to this). This is the most perplexing thing, that it works in the windows app but not from this web site. ASP.NET has full permissions on that folder to do whatever it wants. It can open the image fine, and the bitmap it creates from the FileStream is the actual image.
edit: Also, the ReadTIFF function right now copies the FileStream into a MemoryStream, ensuring its a not a problem streaming from disk (the entire file is in memory).
How are you passing the filepath to the web application?
It is possible that the function which Decodes might be swallowing some exception.
Use reflector to examine the library (if you have not written it).
I agree. It seems your problem is most probably related to User rights on the directory where you're trying to access the files from. Try giving your Web users the Full access rights on the source directory.
EDIT
Solution Found: The problem was that the open file dialog was changing the CurrentWorkingDirectory. The reason the website never worked, was because the Environment.CurrentDirectory was set incorrectly. When I manually set the CurrentDirectory to the websites' bin folder, parsing works correctly.
Small update. Using the Windows App, and selecting the file via OpenFileDialog, will cause the barcode decoder to fail. Technically, I am using the exact same string to hand to the parser ("c:\testing\image.tif"), yet when I use the OpenFileDialog to get the string, the decoder fails. Is there a clue in this?
update: In fact, even if I don't use the string the OpenFileDialog gives me, if I just open the file dialog at all, it will fail. I don't get this. It's something simple. I need to debug the C++ DataMatrix library, really.

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