Develop Reference

How do I get my c# console application to run with an app.config?

This is peculiar to me although I'm sure I'm missing something simple and basic. I have a console application that reads a SQL connection from an app.config. It works fine in Visual Studio. When I move three items to a directory to test, the .exe, the app.config, and the crystal report that it needs to function, it won't read from the app.config.
Console.WriteLine("about to get connection string...");
var connectionString = ConfigurationManager.ConnectionStrings["InformConnectionString"].ConnectionString;
It bombs on the var connectionString line with an unhandled exception Object reference not set to an instance of an object. Again, works fine in the development environment, just not in the production directory.

It is because the app.config is renamed to YourAppName.exe.config when it is compiled. Look in your bin/debug folder or bin/release folder. There you find the used config-files

Configuration.Save operation not working for some machine

I have a C# executable reading and updating it's configuration file (app.exe.config) at runtime, specifically, the "appSettings" section. After I make two changes to two key values and save them using the Configuration.Save() method, an "access to the path" error is thrown, but only on some users' machines (so far 2 reports out of 10,000). We have never seen this issue in-house, only in production.
The Configuration.Save() method seems to be the issue based on our program's log file. When a problem with this call happens a "ConfigurationErrorsException" occurs because the configuration file could not be written to -or- the configuration file has changed. The configuration file is in the same directory as the application. This is a Dot Net 4 application running on a Windows 7 PC.
The code is:
Configuration configuration = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
configuration.AppSettings.Settings["Last Updated Package"].Value = packageVersion;
configuration.AppSettings.Settings["Copy Updated Files"].Value = bool.TrueString;
configuration.Save(ConfigurationSaveMode.Minimal);
ConfigurationManager.RefreshSection("appSettings");
The error is:
An error occurred loading a configuration file: Acces to the path 'C:\Program Files (x86)\My Program\bin\guaixcax.tmp' is denied. (C:\Program Files (x86)\My Program\bin\MyProgram.exe.Config)
Is this a permissions issue, or can I add something to either the code or config file to fix this issue?

I have had similar issues with .NET program installations. It has always been a permissions issue. To test if this is your problem, you should try running your application as an unprivileged user - developers tend to have administrator rights...whenever they can manage it.
If it fails, edit the security of the config file (as an administrator) to allow the "Users" group write access to your "bin" folder, and try it again. If it works, you've identified the problem. Then you can figure out what the best solution is. Some options would be:
Set access rights to necessary files/folders from your installer to work for the users that will run the application
Run the application as a user with admin rights (NOT a good idea from a security best-practices point of view)
Instead of modifying the main app settings file, create a separate settings section referencing a file that has the data that can be changed:
<configuration>
<configSections>
...
<section name="MyChangableSettings" type="My.Namespace, ChangableSettingsClass"/>
</configSection>
...
<MyChangableSettings configSource="Path\To\Writable\StorageDir\mySettings.config"/>
</configuration>

Could not write to output file -- Access is denied

I recently switched computers and copied all my projects over to my new local drive. I reformatted the computer I'm on now so it was pretty much a clean machine. Everything seemed to be working fine, but when I opened one of my projects that I had been running from my old machine, it would no longer compile, and I get the following error message:
Could not write to output file 'c:\Users\user\Documents\Projects\RegressionWeb\OnetouchUpload\obj\debug\OneTouchUpload.dll' -- 'Access is denied.'
I'm getting an error like that for each project I have in my solution. I'm also getting this error:
Unexpected error creating debug information file 'c:\Users\user\documents\projects\RegressionWeb\RegressionWeb\obj\Debug\RegressionWeb.PDB' Access is denied
I've searched high and low, and the only similar issues I could find online related specifically to ASP.NET and IIS, neither of which has anything to do with my project (My projects are class libraries of mostly NUnit tests with some support classes).
I am the administrator on my local machine. I have already taken ownership of every file in the project using takeown /f .\RegressionWeb /r /d y and also tried to ensure that nothing had a status of Read-only, but the following file threw an error when I tried changing the read-only property of it's parent folder:
An error occurred applying attributes to the file:
C:...\Regressionweb.sln.DotSettings.user
Access is denied
Basically this project was working perfectly and had no errors from my old computer. After copying over everything, this DotSettings.user file will not be modified, and Visual Studio can't write to any of the dll files. I'm sure the answer must lie in a Visual Studio setting somewhere. Any and all suggestions would be greatly appreciated.

I think Karl has it right. I had a similar situation once, and what I did was delete the file in question, clean the solution, and then rebuild. If the project needs that file it should recreate it; in my case it didn't need it because it never recreated it, but the project ran just fine.
One other thing I would recommend; you may be selecting the read-only attribute of the parent folder off and selecting this setting to recurse through all sub-folders and files, but that doesn't mean that's what's happening. For all your sub-folders and files (especially the ones that are cropping up as errors) inspect each one individually and make sure the read-only attribute is off.

My money is on your files are read-only. Verify they are read-only and change them or add your files to a source control system and let them get handled by that.

I was able to get this working by closing Visual Studio and then opening it again, but being careful to run Visual Studio "As Administrator". To do this, from the Start menu, right click on Visual Studio and choose "Run as Administrator".

it seems that the same error is sometimes displayed when the app pool user doesn't have access to the %TMP%/%TEMP% folder.
You'll need to grant IIS_IUSRS read and modify access over the temp folder of the user the app pool is running as.
This could either be the temp folder in the app pool user's profile, e.g. c:\Windows\ServiceProfiles\NetworkService\AppData\Local\Temp, or the system temp folder at c:\windows\temp.

See if it is related to this:Could not write to output file - Access is denied
. That would be a bit of a bugger to track down. In this case the project is self-referencing the dll and preventing access to the file.

This has a very simple solution, you just have to make sure that your directory name(folder name) is not the same as your file name. I created a folder by the name Pointers, my code was in a file pointers.cpp. When I compiled the code it kept showing the same error. I just had to change the directory or folder name to L1_pointers. You can change it to anything you want and it worked.

Problems while reading value from app.config file

I am making one windows application in c# in where i added one file as app.config file.I have written some code in that file as
<appSettings>
<add key ="FlagForArchiving" value="true"/>
</appSettings>
In 'program.cs' file i am reading this value as
ConfigurationSettings.AppSettings["FlagForArchiving"].ToString();
On local machine i can retrieve value from config file but whenever i am building that application and running on any other machine then I cant read the value from config file.I am trying to run my application on windows 7.Please help me.Thanks in advance.

app.config is renamed to <MyProgramName>.exe.config when you build. When your program runs it will look for that <MyProgramName>.exe.config file, not app.config.
You need to deploy the renamed file (<MyProgramName>.exe.config) along with your program.
In your case, you need to copy over OBViewer.exe, OBViewer.exe.config, and any other files that OBViewer.exe depends on (e.g. other .dll assemblies in your debug/release directory).
By the way, this renamed file is often commonly referred to as "app.config", even if it doesn't have the same filename.

and the app.config file exists on the other machine?
Before reading check if it exists
The exception you get says whats incorrect: "FileNotFoundException"
EDIT
here is the correct way!
if (File.Exists(AppDomain.CurrentDomain.SetupInformation.ConfigurationFile))
{
MessageBox.Show(ConfigurationSettings.AppSettings["FlagForArchiving"].ToString());
}

Windows Service Config File C#

I've developed a windows service application using Visual Studio 2008 / C#.
I have an app.config file in the project. When installed, the app.exe.config file appears beside the executable but it appears not to be reading the values from it when I try to access them through ConfigurationManager.AppSettings.
Has it copied the config file elsewhere or is there some other problem I don't know about?
Thanks in advance,
Martin.
Edit:
The config file name is infact my_exe_file_name.exe.config, it looks like:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<appSettings>
<add key="RuntimeFrequency" value="3" />
</appSettings>
</configuration>
and I am trying to read via:
ConfigurationManager.AppSettings["RuntimeFrequency"]
The debug value I continually see is '1' and not '3'. Am I doing something wrong here?

I located the error and it was related to file permissions. After installing the service, my local user account didn't have access to modify the app.exe.config file.
The tool I was using to edit was not informing me it was being denied access to save the file - that's notepad++ if anyone is interested - so I couldn't see that it wasn't saving over the old config file.
Solved now, thanks everyone.
Martin.

When you are in debug mode check and see what settings are in the my_exe_file_name.vshost.exe.config Also make sure you adjust this in the app.config file. Visual studio should update the final config file in your bin/debug folders.

Maybe you are updating the wrong config file. You should double check that using
System.Configuration.ConfigurationManager.OpenExeConfiguration(PATH_TO_CONFIG);

Generally for the Windows Services that I write, i drop the appName.exe.config file into C:\WINDOWS\system32\
Perhaps you have an older version in that directory, which is where your service is getting the value, even though you've updated the config file in your project.

App.config file should be renamed to your_exe_file_name.exe.config and placed near the exe file.

Is it possible that you have more than one instance of the RuntimeFrequency entry defined? The ConfigurationManager reads the file from top to bottom and processes each setting individually. Therefore, the last value of RuntimeFrequency that is defined in the file is the one it will use.
If you want to know for sure if your file is being used, I would simply remove or comment out any definition for RuntimeFrequency (copy/paste errors do happen) and wait to see an application error when ConfigurationManager attempts to reference an entry in AppSettings that does not exist.