Develop Reference

Saving appSettings to an external file

I need to have appSettings in a separate file and in a parent directory and save it at runtime:
Bin/app.config:
<appSettings file="../Configuration/appSettings.config">
<add key="commonSetting" value="123"/>
</appSettings>
Configuration/appSettings.config:
<appSettings>
<add key="externalSetting" value="ABC"/>
</appSettings>
When I try to modify and save external settings, they are saved in Bin\app.config instead of Configuration/appSettings.config:
System.Configuration.Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
ConfigurationManager.AppSettings["externalSetting"] = "DEF";
config.Save();
I can't use configSource attribute because external file has to be in a subdirectory of Bin.
(Similar problem raised in AppSettings on a different .config file not being updated but not the same constaints)
Any idea of how to fix / work around it?
EDIT:
I also tried with this setter, same unexpected result:
System.Configuration.Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
config.AppSettings.Settings["externalSetting"].Value = "DEF";
config.Save();

Read separate web.config file outside the application folder

I need to read web.config file, outside the application's folder (located in any other directory).
I tried this code:
string filePath = #"C:\Users\Idrees\Downloads\New folder\Web.config";
Configuration c1 = ConfigurationManager.OpenExeConfiguration(filePath);
var value1 = c1.AppSettings.Settings["Key1"].Value;
But it is giving me the error:
Object reference not set to an instance of an object.
Because here, c1.AppSettings is an object, but c1.AppSettings.Settings contains not items (hence 0 Count). It is not really loading the AppSettings keys. When trying to read any Key from Settings collection, it gives this error.
Is there any way how to load AppSettings keys from a web.config file outside the application folder.
If I put same file within application folder, then it reads the keys successfully.
This is my sample config file's content:
<?xml version="1.0" encoding="utf-8"?>
<!--
For more information on how to configure your ASP.NET application, please visit
http://go.microsoft.com/fwlink/?LinkId=169433
-->
<configuration>
<connectionStrings>
<!--here goes my connection strings-->
</connectionStrings>
<appSettings>
<add key="Key1" value="Value1" />
<add key="Key2" value="Value2" />
<add key="Key3" value="Value3" />
</appSettings>
</configuration>
I have a web application already running on my server. And I need to develop a small utility which has to do some job in database, and I don't want to write db credentials or connection string(and some other additional app-settings) in each application, I want it to read same thing from web.config.

You can using ConfigurationManager to read arbitrary configuration files by opening a mapped exe configuration as follows:
var filePath = #"C:\Users\Idrees\Downloads\New folder\Web.config";
var fileMap = new ExeConfigurationFileMap { ExeConfigFilename = filePath };
var configuration = ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None);
var value = configuration.AppSettings.Settings["Key1"].Value;

As I understand from your comment you want some kind of shared configuration accross multiple app on the same computer. You may consider using external file like this :
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
</startup>
<connectionStrings configSource="config\connString01.config"/>
<appSettings file="config\config01.config">
<add key="Var3" value="Var3 value from main config file"/>
</appSettings>
in above .config example connectionStrings is sourced from an other file. Below an example what can be such an external config file:
<connectionStrings>
<add name="SQLConnectionString01" connectionString="Data Source=sourcename01;Initial Catalog=cat01;Persist Security Info=True;Integrated Security=true;"/>
</connectionStrings>

Read documentation: ConfigurationManager.OpenExeConfiguration on MSDN
public static Configuration OpenExeConfiguration(
string exePath
)
This is EXE path

C# Opening a configuration file from an arbitrary location

At:
Using ConfigurationManager to load config from an arbitrary location
I found what seems like a solution. A project I'm working on uses an appSettings.config file location on the network. BUT when I tried to use the referenced code:
System.Configuration.ConfigurationFileMap fileMap = new ConfigurationFileMap("Z:\Settings\appSettings.config"); //Path to your config file
System.Configuration.Configuration configuration = System.Configuration.ConfigurationManager.OpenMappedMachineConfiguration(fileMap);
So far so good. The appSettings.config file looks like this:
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<appSettings>
<add key="Environment" value="Development" />
</appSettings>
</configuration>
BUT then I get to this following line:
var settings = configuration.AppSettings.Settings;
or anything using it, like Settings.Count, I get an Invalid Cast Exception. Basically, how would I get the value for "Environment" from this?

I found this works:
System.Configuration.ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap();
fileMap.ExeConfigFilename = #"Z:\appSettings.config"; //Path to your config file
System.Configuration.Configuration configuration = System.Configuration.ConfigurationManager.OpenMappedExeConfiguration(fileMap, ConfigurationUserLevel.None); // OpenMappedMachineConfiguration(fileMap);
return configuration.AppSettings.Settings["Environment"].Value;
This works without error.

Trying to get String from App.config File

I'm desperately trying to make a working app.config file in which I want to save the connection strings for my database connections.
This is my app.config file:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<appSettings>
<add key="Con" value="User Id = *******;password=**;data source= (DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST = ******)(PORT = 1525))(CONNECT_DATA =(SERVER = DEDICATED)(SID = emtst)))"/>
</appSettings>
</configuration>
And when I try to read it here:
string connStr = ConfigurationManager.AppSettings["Con"];
this.odacManager = new ODACManager(connStr);
I just get an empty string. I'm using System.Configuration.
I've also tried to use
ConfigurationManager.Connectionstring["Con"].ConnectionString
but that also didn't work.

You should be using the <connectionStrings> element in your config file:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<connectionStrings>
<add name="Con"
connectionString="User Id=*******;password=**;data source=(DESCRIPTION =(ADDRESS = (PROTOCOL = TCP)(HOST = ******)(PORT = 1525))(CONNECT_DATA =(SERVER = DEDICATED)(SID = emtst)))"/>
</connectionStrings>
</configuration>
and then read it out as:
string connStr = ConfigurationManager.ConnectionStrings["Con"].ConnectionString;
Update:
In .NET, class library projects cannot have their own config files - they won't be used and won't be evaluated at runtime.
If your class library needs any configuration, you need to put that configuration into the host application's app.config (or web.config) so that the class library can find it there (and use it).

try
System.Configuration.ConfigurationSettings.AppSettings["Con"].ToString();

.net and .config files

I have the following stored in a stores.config file inside my asp.net website's root folder.
<configuration>
<appSettings>
<add key="ClientId" value="127605460617602"/>
<add key ="RedirectUrl" value="http://localhost:49548/Redirect.aspx"/>
</appSettings>
</configuration>
How can I use string Clientid = ConfigurationManager.AppSettings["ClientId"].ToString(); to call it up from that file? Calling it as it of course does not work as it is looking for it in web.config.
I do not want to put the appSettings in the web.config file. Is that allowed?

You can reference your stores.config file from web.config
<configuration>
<appSettings file="stores.config">
</appSettings>
<configuration>
Your stores.config file should have the following structure:
<appSettings>
<add key="ClientId" value="127605460617602"/>
<add key ="RedirectUrl" value="http://localhost:49548/Redirect.aspx"/>
</appSettings>
Alternatively you can also use:
ConfigurationManager.OpenMappedExeConfiguration Method (ExeConfigurationFileMap, ConfigurationUserLevel)
For example:
// Map the new configuration file.
var configFileMap = new ExeConfigurationFileMap();
configFileMap.ExeConfigFilename = "stores.config";
// Get the mapped configuration file
var config = ConfigurationManager.OpenMappedExeConfiguration(configFileMap, ConfigurationUserLevel.None);
var clientid = config.AppSettings["ClientId"];