I need to change the config file myApp.exe.configat runtime. How to make sure that the program would be started to work with a modified file without leaving the program?
It may be necessary to use a ConfigurationManager.
Thank you!
It's definitely possible, I did this at work a while back. Essentially, you can load a new app.config file into memory, then tell .NET to use the new file. From that point on, all variables in the Configurarion section change when read using the standard .NET calls.
Sorry I cant give specifics, you might have to Google some more - but at least you know its possible!!
Having said this, I believe this is the wrong architectural path to go down. Far better to store your settings in an external file in your own format. It really is a royal pain to update app.config, and if we hadnt had to do it for compatibility reasons with legacy assemblies it would not have been worth it in the least. The legacy assemblies used WCF which in itself was a mistake. WCF is a ghastly architectural morass, with few redeeming features compared to any of the modern alternatives.
Update
See Overriding App.Config settings.
See Change default app.config at runtime.
Related
my question is do I need to convert or make any changes to web.config file of solution (web application) of vb or only if I convert the .vb files to .cs files that will be enough?
And if any other changes I have to make or any suggestions please do tell me, this is my first time with vb so I am not that knowledgeable.
Well, you no doubt starting a whole new project from scratch. I would let it create it own web.config. And then say in settings create your conneciton strings etc. (assuming you using settings).
And setting up references etc. will also often put assembly references in that web config. You might be able to just copy the whole web config, and do the reverse (remove some things).
I would actually start with a fresh web config, since it would be a chance to leave behind a lot of stuff and things that often get built up over the years. However, I don't really see what the benefits are of spending that money to convert from vb to c#. If I was spending that kind of money, then I would make the jump to mvc and the newer .net stack.
So, you probably can just copy the web config over, but I would take this opportunity to start with a fresh one, and then wind up adding the little bits and parts you need as you convert to c#. That way you wind up with a much cleaner web.config file.
so you can and should be able to just copy the config file over to the new project - but I would not for above reasons.
As noted, I can't see how this cost can be justified unless you migration is to a newer technology anyway.
only changing the code-behind files worked for me, did not change the config file.
The system for saving/reloading values is convenient but it has one annoying gotcha for a developer: The ID changes on every recompile and thus it's basically useless in development. Are there any easy fixes to this? Google only tells me others have the same annoyance so I doubt there's anything other than doing it myself.
Edit: David Yew is right about the file.
Have you set the version of your exe in the properties of the project? If you set this to something other than 0.0.0.0 I think it will maintain the settings for you.
I want to hide app.config. There are some things like webservice address that shouldn't be visible to user. Maybe it`s some way to put this config in resources?
Thanks
I think that encrypting app/web config would be a better option.
See this topic for more info Encrypting appSettings in web.config
Also codeproject has a plenty of articles.
To the user of the code? To the application user? This question is very generalized and not specific.
Try to figure out whether the settings in your app.config file can be applied programmatically.
The most settings in the .NET framework can be used declarative and programmatically.
If you are really concerned about end-users snooping into the configuration details of your program, it will be very hard to hide such information (even if it's contained in code since it can be reverse compiled using tools like Reflector). You can only make it harder by applying some encryption scheme, like obfuscation that encrypts the internal string table of your assembly. Then again, it's easy to use a packet sniffer tool to obtain the remote URI your program is communicating with.
The way I currently handle this is by having multiple config files such as:
web.config
web.Prod.config
web.QA.config
web.Dev.config
When the project gets deployed to the different environments I just rename the corresponding file with the correct settings.
Anyone have suggestions on how to handle this better?
EDIT:
Here are some of the things that change in each config:
WCF Client Endpoint urls and security
Custom Database configs
Session connection strings
log4net settings
Scott Gu had an article on this once. The solution he presented was to use a Pre-build event to copy the correct config into place depending on the build configuration chosen.
I also noticed that there already is a similar question here on SO.
Transforms seem really helpful for this. You can replace certain sections with different rules.
http://msdn.microsoft.com/en-us/library/dd465318(v=vs.100).aspx
The way we've been doing it is to override the AppSettings section:
<appSettings file="../AppSettingsOverride.config">
<add key="key" value="override" />
...
</appSettings>
This only works for the appSettings section and so is only useful to a degree. I'd be very interested in more robust solutions.
Edit Below
Just watched this:
http://channel9.msdn.com/shows/10-4/10-4-Episode-10-Making-Web-Deployment-Easier/
VS2010 has config transforms which look pretty awesome, should make multiple configurations a complete breeze.
In Visual Studio, I create xcopy build events and I store all the config files in a /config folder. You only need one event for all configurations if you name your files after the build configuration: i.e. overwriting web.config with /config/web.$(Configuration).config
My favorite way to tackle this is with the configSource attribute. Admittedly I only use this on one element (<connectionStrings>) but it does provide an easy way to swap in and out different segments of a web.config (which I do during install time via a WebSetup project).
I also use the web.DEV.config, web.TEST.config, web.PROD.config etc.
I find this way the most easiest, simplest and straight-forward way if your projects are not complex. I don't like making things more complicated than neccessary.
However, I have used NAnt and I think it works well for this. You can set up builds for your different environments. NAnt takes some reading to learn how to use it but it's pretty flexible.
https://web.archive.org/web/20210513225023/http://aspnet.4guysfromrolla.com/articles/120104-1.aspx
http://nant.sourceforge.net/
I used it along with CruiseControl.net and NUnit to perform automatic daily builds with unit test validation and thought they worked well together.
It really depends on what the difference is between the environments that is causing you to use different web.config files. Can you give more information as to why each environment currently needs a different one?
We have a few workarounds (not all of them are done with web.config but the same idea)
We include multiple configuration files in the packaged deployment. During installation we specify environment that we are installing on.
Migrate all environment specific settings to the Database server for that environment. WebServer provides its environment when requesting server name
Provide multiple settings (1 per environment) and using code request different settings.
Combination of 2 and 3 (Override a part of the settings based on the environment - for example application server name)
Through most different version management software (subversion, git, etc) you can ignore specific files.
Thus, in subversion, I'd have:
configure.template.php - This file is versioned and contains templated configuration data, such as empty DSN's
configure.php - This file is ignored, so that changes to it do not get tracked.
In subversion, the way to do this is:
svn pe svn:ignore .
It'll open your editor, then you type
configure.php
Save, exit, checkin your changes, and you're good to go.
I'm really confused by the various configuration options for .Net configuration of dll's, ASP.net websites etc in .Net v2 - especially when considering the impact of a config file at the UI / end-user end of the chain.
So, for example, some of the applications I work with use settings which we access with:
string blah = AppLib.Properties.Settings.Default.TemplatePath;
Now, this option seems cool because the members are stongly typed, and I won't be able to type in a property name that doesn't exist in the Visual Studio 2005 IDE. We end up with lines like this in the App.Config of a command-line executable project:
<connectionStrings>
<add name="AppConnectionString" connectionString="XXXX" />
<add name="AppLib.Properties.Settings.AppConnectionString" connectionString="XXXX" />
</connectionStrings>
(If we don't have the second setting, someone releasing a debug dll to the live box could have built with the debug connection string embedded in it - eek)
We also have settings accessed like this:
string blah = System.Configuration.ConfigurationManager.AppSettings["TemplatePath_PDF"];
Now, these seem cool because we can access the setting from the dll code, or the exe / aspx code, and all we need in the Web or App.config is:
<appSettings>
<add key="TemplatePath_PDF" value="xxx"/>
</appSettings>
However, the value of course may not be set in the config files, or the string name may be mistyped, and so we have a different set of problems.
So... if my understanding is correct, the former methods give strong typing but bad sharing of values between the dll and other projects. The latter provides better sharing, but weaker typing.
I feel like I must be missing something. For the moment, I'm not even concerned with the application being able to write-back values to the configuration files, encryption or anything like that. Also, I had decided that the best way to store any non-connection strings was in the DB... and then the very next thing that I have to do is store phone numbers to text people in case of DB connection issues, so they must be stored outside the DB!
If you use the settings tab in VS 2005+, you can add strongly typed settings and get intellisense, such as in your first example.
string phoneNum = Properties.Settings.Default.EmergencyPhoneNumber;
This is physically stored in App.Config.
You could still use the config file's appSettings element, or even roll your own ConfigurationElementCollection, ConfigurationElement, and ConfigurationSection subclasses.
As to where to store your settings, database or config file, in the case of non-connection strings: It depends on your application architecture. If you've got an application server that is shared by all the clients, use the aforementioned method, in App.Config on the app server. Otherwise, you may have to use a database. Placing it in the App.Config on each client will cause versioning/deployment headaches.
Nij, our difference in thinking comes from our different perspectives. I'm thinking about developing enterprise apps that predominantly use WinForms clients. In this instance the business logic is contained on an application server. Each client would need to know the phone number to dial, but placing it in the App.config of each client poses a problem if that phone number changes. In that case it seems obvious to store application configuration information (or application wide settings) in a database and have each client read the settings from there.
The other, .NET way, (I make the distinction because we have, in the pre .NET days, stored application settings in DB tables) is to store application settings in the app.config file and access via way of the generated Settings class.
I digress. Your situation sounds different. If all different apps are on the same server, you could place the settings in a web.config at a higher level. However if they are not, you could also have a seperate "configuration service" that all three applications talk to get their shared settings. At least in this solution you're not replicating the code in three places, raising the potential of maintenance problems when adding settings. Sounds a bit over engineered though.
My personal preference is to use strong typed settings. I actually generate my own strongly typed settings class based on what it's my settings table in the database. That way I can have the best of both worlds. Intellisense to my settings and settings stored in the db (note: that's in the case where there's no app server).
I'm interested in learning other peoples strategies for this too :)
I think your confusion comes from the fact that it looks like your first example is a home-brewed library, not part of .NET.
The configurationmanager example is an example of built-in functionality.
I support Rob Grays answer, but wanted to add to it slightly. This may be overly obvious, but if you are using multiple clients, the app.config should store all settings that are installation specific and the database should store pretty much everything else.
Single client (or server) apps are somewhat different. Here it is more personal choice really. A noticable exception would be if the setting is the ID of a record in the database, in which case I would always store the setting in the database with a foreign key to ensure the reference doesn't get deleted.
Yes - I think I / we are in the headache situation Rob descibes - we have something like 5 or 6 different web-sites and applications across three independent servers that need to access the same DB. As things stand, each one has its own Web or App.config with the settings described setting and / or overriding settings in our main DB-access dll library.
Rob - when you say application server, I'm not sure what you mean? The nearest thing I can think is that we could at least share some settings between sites on the same machine by putting them in a web.config higher in the directory hierarchy... but this too is not something I've been able to investigate... having thought it more important to understand which of the strong or weak-typed routes is 'better'.