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Edit app.config file and read settings

I have a app.config file.
I have settings there.
I want to modify settings after my build and then read it from file.
I mean I want to change settings by edeting a file.
I know how to change settings programmaticaly but I need it by editing file.
No I'm trying to do so:
private void ReadSettings()
{
string appPath = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().Location);
string settingsPath = Path.Combine(appPath, "app.config");
ExeConfigurationFileMap configFileMap = new ExeConfigurationFileMap();
configFileMap.ExeConfigFilename = settingsPath;
System.Configuration.Configuration config = ConfigurationManager.OpenMappedExeConfiguration(configFileMap, ConfigurationUserLevel.None);
string value=config.AppSettings.Settings["Type"].Value;
}
My settings:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<sectionGroup name="userSettings" type="System.Configuration.UserSettingsGroup, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" >
<section name="RxTest.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" allowExeDefinition="MachineToLocalUser" requirePermission="false" />
</sectionGroup>
</configSections>
<userSettings>
<MyApp.Properties.Settings>
<setting name="Type" serializeAs="String">
<value>document</value>
</setting>
</RxTest.Properties.Settings>
</userSettings>
</configuration>
Problem is that there is nothing in Settings property.
What shuld I do to read settings from edeted file?

The UserSettings written in your app.config file should be automatically added into it by adding an entry into your properties.
You can achieve getting the values from your properties like this:
string value = Properties.Settings.Default.Type;
EDIT I:
To be sure you always have the freshest value, you can either refresh a section:
ConfigurationManager.RefreshSection(sectionName);
Or you can reaload the file:
Properties.Settings.Default.Reload();

How to get all sections by name in the sectionGroup applicationSettings in .Net 2.0

Here's the idea I had:
I want a small executable to have an app.config file with multiple sections that are situated under the sectionGroup "applicationSettings" (not "appSettings", I don't need to write to the file). Each section would have a name corresponding to a module that should be loaded if set.
Here's an example:
<configuration>
<configSections>
<sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" >
<section name="Executable" type="System.Configuration.ClientSettingsSection, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
<section name="FirstModule" type="System.Configuration.ClientSettingsSection, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</sectionGroup>
</configSections>
<applicationSettings>
<Executable>
<setting name="MyFirstSetting" serializeAs="String">
<value>My awesome feature setting</value>
</setting>
</Executable>
<FirstModule path="path to the modules assembly">
<setting name="ImportantSettingToTheModule" serializeAs="String">
<value>Some important string</value>
</setting>
</FirstModule>
</applicationSettings>
</configuration>
Now if I define the FirstModule section, I want my application to load its assembly. If the section is not defined, the module should not be loaded. This should be true for not only one module but a not yet defined number of them.
So I basically need to find out about the defined sections at runtime. How would I do that?
In addition I want this to become a portable executable (= it has to run on Mono as well) that is backwards compatible to .NET 2.0.
It might be interesting to have a look at the project on GitHub (currently at this commit).

Take a look at the ConfigurationManager.OpenExeConfiguration function to load in your configuration file.
Then on the System.Configuration.Configuration class that you'll get back from ConfigurationManager.OpenExeConfiguration you'll want to look at the SectionGroups property. That'll return a ConfigurationSectionGroupCollection in which you'll find the applicationSettings section.
In the ConfigurationSectionGroupCollection there will be a Sections property which contains the Executable and FirstModule ConfigurationSection objects.
var config = ConfigurationManager.OpenExeConfiguration(pathToExecutable);
var applicationSettingSectionGroup = config.SectionGroups["applicationSettings"];
var executableSection = applicationSettingSectionGroup.Sections["Executable"];
var firstModuleSection = applicationSettingSectionGroup.Sections["FirstModule"];
You will want to check for null after getting the ConfigurationSectionGroupCollection object or ConfigurationSection objects. If they are null they don't exist in the configuraiton file.
You can also get the sections by using ConfigurationManager.GetSection
var executableSection = (ClientSettingsSection)ConfigurationManager
.GetSection("applicationSettings/Executable");
var firstModuleSection = (ClientSettingsSection)ConfigurationManager
.GetSection("applicationSettings/FirstModule");
Again, if the objects are null they don't exist in the configuration file.
To get a list of all the section names and groups you could do:
var config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
// use the line below instead if you want to load an app.config for a
// different application other than the one the code is running in
// var config = ConfigurationManager.OpenExeConfiguration(pathToExecutable);
var names = new List<string>();
foreach (ConfigurationSectionGroup csg in config.SectionGroups)
names.AddRange(GetNames(csg));
foreach (ConfigurationSection cs in config.Sections)
names.Add(cs.SectionInformation.SectionName);
private static List<string> GetNames(ConfigurationSectionGroup configSectionGroup)
{
var names = new List<string>();
foreach (ConfigurationSectionGroup csg in configSectionGroup.SectionGroups)
names.AddRange(GetNames(csg));
foreach(ConfigurationSection cs in configSectionGroup.Sections)
names.Add(configSectionGroup.SectionGroupName + "/" + cs.SectionInformation.SectionName);
return names;
}

Save and reload app.config(applicationSettings) at runtime

I've stored configuration of my application in the app.config, by Visual Studio I've created some application key on the settings tab of project properties dialog, then I've set this key at application level(NOT at user level).
Visual Studio automatically generate the following xml file (app.config) :
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" >
<section name="AleTest.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</sectionGroup>
</configSections>
<applicationSettings>
<AleTest.Properties.Settings>
<setting name="DatabasePath" serializeAs="String">
<value>Test.s3db</value>
</setting>
<setting name="DatabaseUser" serializeAs="String">
<value />
</setting>
<setting name="DatabasePass" serializeAs="String">
<value />
</setting>
</AleTest.Properties.Settings>
</applicationSettings>
</configuration>
Now I want to save and reload the settings at runtime, here's my code that allow to save the value DatabasePath in the configuration file:
Configuration config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
ConfigurationSectionGroup applicationSectionGroup = config.GetSectionGroup("applicationSettings");
ConfigurationSection applicationConfigSection = applicationSectionGroup.Sections["AleTest.Properties.Settings"];
ClientSettingsSection clientSection = (ClientSettingsSection)applicationConfigSection;
//Database Configuration Setting
SettingElement applicationSetting = clientSection.Settings.Get("DatabasePath");
applicationSetting.Value.ValueXml.InnerXml = this.textBoxPath.Text.Trim();
applicationConfigSection.SectionInformation.ForceSave = true;
config.Save();
The problem is that with this code the new settings aren't loaded by application until I restart the application; is there a way to reload the config settings at runtime?
I also want to replace the fixed value of the name of applicationSettings section (AleTest.Properties.Settings) with a variable value, exist a variable in the framework the assume this value (AleTest.Properties.Settings) ?

You need to make a call to ConfigurationManager.RefreshSection in order to have the values re-read from disk.

I did a some tests and here is result.
For auto generated class Settings the call of ConfigurationManager.RefreshSection("applicationSettings"); doesn't apply the modified values for members marked with ApplicationScopedSettingAttribute, it applies the changes to future calls via ConfigurationManager members (and not sure about UserScopedSettingAttribute).
Instead call Settings.Default.Reload();

What you want is accomplish able by creating an custom ConfigSection which allows you more control and allows you to change the name. Configuration manager has a refresh section which will allow you reload the data.

Aleroot's code for updating values worked fine.
In spite of Properties.Settings being write only (no set).
To refresh, this worked for me:
ConfigurationManager.RefreshSection("applicationSettings");
But I'm using this to access the parameter:
string test = Properties.Settings.Default.MyString;
MessageBox.Show("Paramètres/Settings MyString = " + test);

Updating <appname>.config file from an Custom Installer Class Action

I've tried updating my application's .config file during installer (via a .NET Installer Class Action). But, I can't seem to get ConfigurationManager to list any properties or be able to set anything.
I learned of this approach from several stackoverflow posts that pointed me to this guide: http://raquila.com/software/configure-app-config-application-settings-during-msi-install/
I've investigated the differences between my project and his and noticed that my configuration files are formatted differently. I believe this has to do with the fact that i'm using "Settings" files.
Config files formatted in the guide look like:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<appSettings>
<add key="Param1" value="" />
<add key="Param2" value="" />
<add key="Param3" value="" />
</appSettings>
</configuration>
Where mine looks like:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<sectionGroup name="userSettings" type="System.Configuration.UserSettingsGroup, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" >
<section name="MyAppName.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" allowExeDefinition="MachineToLocalUser" requirePermission="false" />
<section name="MyAppName.Settings1" type="System.Configuration.ClientSettingsSection, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" allowExeDefinition="MachineToLocalUser" requirePermission="false" />
</sectionGroup>
<sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" >
<section name="MyAppName.Settings1" type="System.Configuration.ClientSettingsSection, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</sectionGroup>
</configSections>
<userSettings>
<MyAppName.Properties.Settings>
<setting name="TESTSETTING" serializeAs="String">
<value>asdfasdfasdf</value>
</setting>
</MyAppName.Properties.Settings>
<MyAppName.Settings1>
<setting name="VerboseErrorMode" serializeAs="String">
<value>False</value>
</setting>
<applicationSettings>
<MyAppName.Settings1>
<setting name="RunOnStartup" serializeAs="String">
<value>True</value>
</setting>
</MyAppName.Settings1>
</applicationSettings>
</configuration>
To shed some light on what was going on... I tried printing out the list of settings like so:
Configuration config = ConfigurationManager.OpenExeConfiguration(exePath);
// Try getting the Settings1 Section
AppSettingsSection appSettings = (AppSettingsSection)config.GetSection("Settings1"); // Also tried myNamespace.Settings1
if (appSettings != null)
{
valList = "Settings1: ";
foreach (string key in appSettings.Settings.AllKeys)
{
string value = appSettings.Settings[key].Value;
valList += ("Key: '" + key + "' = '" + value + "'\n");
}
}
else
{
valList = "appSettings was null";
}
MessageBox.Show(valList);
MessageBox.Show(valList);
I have tried several permutations of this... and in all cases output is "appSettings was null".
I also tried initializing the configuration manager in several different ways...
Configuration config = ConfigurationManager.OpenExeConfiguration(exePath);
MessageBox.Show("Section Count: " + config.Sections.Count);
MessageBox.Show("Has File: " + config.HasFile);
MessageBox.Show("Namespace Declared: " + config.NamespaceDeclared);
config = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
MessageBox.Show("Section Count: " + config.Sections.Count);
MessageBox.Show("Has File: " + config.HasFile);
MessageBox.Show("Namespace Declared: " + config.NamespaceDeclared);
For each of them the section count returned was 20. (I have no idea where the 20 comes from... I would have expected it to be 3).
HasFile was true for the first case and false for the second.
Namespace Declared was false in both cases.
Thanks!
EDIT (6-18-09): Still looking into this question. Anyone else have any ideas? Thanks.
Search Keywords: "Object Reference Not Set to not set to an instance" <-- this occurs when trying to write to a property.

I came across the same problem, after deep investigation, I found out the easiest way to update any part of config files (e.g. app.config), that's by using XPath.
We have an application which connects to web service, during the installation, the user enters the URL of the web service and this should be saved in the following app.config file:
<?xml version="1.0"?>
<configuration>
<configSections>
<sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
<section name="ApplicationServer.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</sectionGroup>
</configSections>
<applicationSettings>
<ApplicationServer.Properties.Settings>
<setting name="ApplicationServer_ApplicationServerUrl" serializeAs="String">
<value>whatever comes from setup should go here</value>
</setting>
</ApplicationServer.Properties.Settings>
</applicationSettings>
</configuration>
Here is the code to do this in the installer class:
public override void Install(System.Collections.IDictionary stateSaver)
{
base.Install(stateSaver);
string targetDirectory = Context.Parameters["targetdir"];
string param1 = Context.Parameters["param1"];
string path = System.IO.Path.Combine(targetDirectory, "app.config");
System.Xml.XmlDocument xDoc = new System.Xml.XmlDocument();
xDoc.Load(path);
System.Xml.XmlNode node = xDoc.SelectSingleNode("/configuration/applicationSettings/Intellisense.ApplicationServer.Properties.Settings/setting[#name='ApplicationServer_ApplicationServerUrl']/value");
node.InnerText = (param1.EndsWith("/") ? param1 : param1 + "/");
xDoc.Save(path); // saves the web.config file
}
Basically, since the config file is a XML based document, I am using XPath expression to locate specific node and change its value.

One thing to try is moving it from install to Commit to ensure that the file has been written first before trying to access it. Alternatively you could use the custom action to write your own file and just alter your config file to point at the alternative xml file.
I worked on a Sharepoint product install where I dug into all of this and I will admit it is very tedious to get working correctly. I was creating config and batch files on the fly based on install parameters.

You can access these settings using the System.Configuration namespace but, its not as simple as I would like and in retrospect using System.Xml.Linq is far simpler. Anyway, here is how I got it to work.
The important concept is, the applicationSettings section is not AppSettings, its a seperate section supported by the ClientSettingsSection type.
//Open the application level config file
ExeConfigurationFileMap exeMap = new ExeConfigurationFileMap();
exeMap.ExeConfigFilename = String.Format("{0}.config",
Context.Parameters["assemblypath"]);
Configuration config = ConfigurationManager.OpenMappedExeConfiguration(exeMap,
ConfigurationUserLevel.None);
//Get the settings section
ClientSettingsSection settingsSection =
config.GetSectionGroup("applicationSettings").Sections
.OfType<ClientSettingsSection>().Single();
//Update "TheSetting"
//I couldn't get the changes to persist unless
//I removed then readded the element.
SettingElement oldElement = settingsSection.Get("TheSetting");
settingsSection.Settings.Remove(oldElement);
SettingElement newElement = new SettingElement("TheSetting",
SettingSerializeAs.String);
newElement.Value = new SettingValueElement();
newElement.Value.ValueXml = oldElement.Value.ValueXml.CloneNode(true);
newElement.Value.ValueXml.InnerText = "Some New Value";
settingsSection.Add(newElement);
//Save the changes
config.Save(ConfigurationSaveMode.Full);
So, as you can see, simple. :-S

Instead of accessing your settings configuration via ConfigurationManager, you should be able to access it via Settings.Default. Settings are more of a Visual Studio feature than a .NET feature...a convenience that makes it easy to visually design your applications configuration rather than manually writing it in appSettings or creating custom configuration sections. However, the configuration schema that is rendered when you use Settings is non-standard, and can be difficult to access manually.
Visual Studio should have generated a Settings class for you when you built your application, and you should be able to access that class via Properties.Settings.Default. It should have a property for each setting, in your case, the following:
Properties.Settings.Default.TESTSETTING
Properties.Settings.Default.VerboseErrorMode
Properties.Settings.Default.RunOnStartup
You should be able to both read and write these settings. A critical thing to note...anything flagged as a "user" setting will not be written back to the {yourapplication}.exe.config file...it will be written to a User.config file in the users isolated profile storage area. This is under C:\Documents and Settings{username} on XP, and C:\Users{username} on Vista, in the AppData folder. Depending on the OS and users profile, the subfolder under the AppData may change, but its completely unique and keyed to a particular version of the application. Installation of a newer version will result in a completely new set of configuration settings stored under the same keyed folder, but a different version subfolder.
I hope this helps. :)

This is what you need: http://social.msdn.microsoft.com/Forums/en-US/csharpgeneral/thread/f89a00eb-9400-48ce-af20-cef78002c14e

How to use a App.config file in WPF applications?

I created an App.config file in my WPF application:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<appsettings>
<add key="xmlDataDirectory" value="c:\testdata"/>
</appsettings>
</configuration>
Then I try to read the value out with this:
string xmlDataDirectory = ConfigurationSettings.AppSettings.Get("xmlDataDirectory");
But it says this is obsolete and that I should use ConfigurationManager which I can't find, even searching in the class view.
Does anyone know how to use config files like this in WPF?

You have to reference the System.Configuration assembly which is in GAC.
Use of ConfigurationManager is not WPF-specific: it is the privileged way to access configuration information for any type of application.
Please see Microsoft Docs - ConfigurationManager Class for further info.

In my case, I followed the steps below.
App.config
<configuration>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
</startup>
<appSettings>
<add key="POCPublishSubscribeQueueName" value="FormatName:Direct=OS:localhost\Private$\POCPublishSubscribe"/>
</appSettings>
</configuration>
Added System.Configuartion to my project.
Added using System.Configuration statement in file at top.
Then used this statement:
string queuePath = ConfigurationManager.AppSettings["POCPublishSubscribeQueueName"].ToString();

In your app.config, change your appsetting to:
<applicationSettings>
<WpfApplication1.Properties.Settings>
<setting name="appsetting" serializeAs="String">
<value>c:\testdata.xml</value>
</setting>
</WpfApplication1.Properties.Settings>
</applicationSettings>
Then, in the code-behind:
string xmlDataDirectory = WpfApplication1.Properties.Settings.Default.appsetting.ToString()

You have to reference System.Configuration via explorer (not only append using System.Configuration). Then you can write:
string xmlDataDirectory =
System.Configuration.ConfigurationManager.AppSettings.Get("xmlDataDirectory");
Tested with VS2010 (thanks to www.developpez.net).
Hope this helps.

You have to add the reference to System.configuration in your solution. Also, include using System.Configuration;. Once you do that, you'll have access to all the configuration settings.

This also works
WpfApplication1.Properties.Settings.Default["appsetting"].ToString()

You can change configuration file schema back to DotNetConfig.xsd via properties of the app.config file. To find destination of needed schema, you can search it by name or create a WinForms application, add to project the configuration file and in it's properties, you'll find full path to file.

There is a good article about Application settings on Microsoft.
According to that you need to:
manually create App.config file (from Project Context menu -> Add -> New Item... -> Application Configuration File.)
add required sections there (I'm using only application scope settings):
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<sectionGroup name="applicationSettings"
type="System.Configuration.ApplicationSettingsGroup, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089">
<section name="DevelopmentEnvironmentManager.WPF.Properties.Settings"
type="System.Configuration.ClientSettingsSection, System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
</sectionGroup>
</configSections>
<applicationSettings>
<DevelopmentEnvironmentManager.WPF.Properties.Settings>
<setting name="SqliteDbFilePath" serializeAs="String">
<value>Database.db</value>
</setting>
<setting name="BackgroundColor" serializeAs="String">
<value>White</value>
</setting>
<setting name="TextColor" serializeAs="String">
<value>Black</value>
</setting>
</DevelopmentEnvironmentManager.WPF.Properties.Settings>
</applicationSettings>
</configuration>
NOTE: Replace 'DevelopmentEnvironmentManager.WPF' with the name of your application.
Additionally, you can go to Properies of the project and add Settings.Designer:
this will add convenient designer to your project, so you don't have to edit XML manually:
To access settings from the code - simply save and close all config editors, build app and access static Propeties (again, do not forget to change app name in the namespace):
string databasePath = DevelopmentEnvironmentManager.WPF.Properties.Settings.Default.SqliteDbFilePath;

I have a Class Library WPF Project, and I Use:
'Read Settings
Dim value as string = My.Settings.my_key
value = "new value"
'Write Settings
My.Settings.my_key = value
My.Settings.Save()