I would like to access the values in the ConfigurationManager.AppSettings object from a MEF plugin which has its own app.config file.
However, the keys from the app.config file are not present in AppSettings after the plugin is loaded.
The keys from the application loading the plugin are still present.
I noticed that using a Settings.settings file allows this behaviour, via the app.config file, so the file must be being loaded somehow.
My plugin looks like:
[Export(IPlugin)]
public class Plugin
{
public Plugin()
{
// reads successfully from app.config via Settings object
var value1 = Settings.Default["Key1"];
// returns null from app.config via ConfigurationManager
var value1 = ConfigurationManager.AppSettings["Key2"]
}
}
The app.config looks like this:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<sectionGroup name="applicationSettings" type="..." >
<section name="Plugin.Settings" type="..." />
</sectionGroup>
</configSections>
<appSettings>
<add key="Key2" value="Fails" />
</appSettings>
<applicationSettings>
<Plugin.Settings>
<setting name="Key1" serializeAs="String">
<value>Works</value>
</setting>
</Plugin.Settings>
</applicationSettings>
</configuration>
I can manually load the app.config file with:
var config = ConfigurationManager.OpenExeConfiguration("Plugin.dll");
var value = AppSettings.Settings["Key2"].Value
but this seems more like a workaround than a solution.
Is there a way to access a MEF plugin's <appSettings> directly, from inside the plugin?
If not, what is recommended?
By default the ConfigurationManager loads the .config for the entry assembly, i.e. the assembly that started the currently executing process.
The correct way to do this would be something like this:
[Export(IPlugin)]
public class Plugin
{
public Plugin()
{
var config = ConfigurationManager.OpenExeConfiguration(Assembly.GetExecutingAssembly().Location);
var value = config.AppSettings.Settings["Key2"].Value;
}
}
This would make the plugin automatically open the .config for the DLL it was compiled in, and fetch values from there.
I'd recommend you to use a dependency injection tool like Unity, in order to provide to your plug-ins the configuration they required. By proceeding in this way, your plug-ins will no longer need to reference System.Configuration.dll.
Related
I have an MVC project and am trying to store my API keys in a separate config file which I will ignore when pushing the code to Git. According to MSDN I should be able to store them in an App.config like like so
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<appSettings>
<add key="APIKey" value="APIKeyValue" />
</appSettings>
</configuration>
I should then be able to read from the file by creating a method in a model
public class KeyTest
{
public string KeyTestCall()
{
string testkey = ConfigurationManager.AppSettings.Get("APIKey");
return testkey;
}
}
and then invoke the method in my controller to assign the value from my App.config file (just so I know I'm getting the value).
public void Testing()
{
KeyTest k = new KeyTest();
ViewBag.x = k;
}
At no point will the code break for a breakpoint, the build will succeed and I can't tell if I'm getting the value or not. Any help is much appreciated. Thanks!
For a web application such as an MVC app, it's a Web.config file, not an App.config
In addition to above (re: web.config vs app.config) if you want to remove "secrets" from source control, this is one way to do it:
In web.config
<?xml version="1.0" encoding="utf-8"?>
<cofiguration>
....
<appSettings file="AppKeys.config">
<add key="SomeOtherSettingThatHasNoSecrets" value="foo" />
...
Then in a separte AppKeys.config file (you can name this whatever.config, sample as named in the above), that you don't add to Git/source control:
<appSettings>
<add key="SomeSecretKey" value="the secret" />
...
Note that AppKeys.config doesn't have an XML declaration.
Hth.
In a web.config file, I have a 3rd party settings section :
<configuration>
<configSections>
<sectionGroup name="TheProduct">
<section name="TheSection" type="TheCompany.TheProduct.TheSectionConfigurationHandler, TheCompany.TheProduct, Version=1.0.0.0, Culture=neutral, PublicKeyToken=b1e9bee111e9429c" />
</sectionGroup>
</configSections>
<TheProduct>
<TheSection somevalue="true" />
</TheProduct>
</configuration>
I want to read the value of this section from another application, but when I try to find the section, I always get null.
Here is my code :
var config = ConfigurationManager.OpenExeConfiguration(
#"C:\inetpub\wwwroot\TheProduct\web.config"
);
var settings = config.GetSection("TheProduct/TheSection"); // always null
What is the correct way to retrieve the config section ?
[Edit] If the calling app, which defines the same section, I can do :
var settings = ConfigurationManager.GetSection("TheProduct/TheSection");
and it's working. Mybe I'm not opening the web.config file using the correct way ?
Using the configuration manager requires that your application be able to instantiate the actual strongly-typed configuration objects. If you can't add a reference to the defining assembly, then your only choice is to use one of the XML api's (either System.Xml or System.Linq.Xml) to read it manually, in which case you won't be using the configuration manager at all.
When are settings from app.config actually read by application?
Suppose I have a windows service and some app settings for it. In code I have a method where some setting is used. Method is being called in every iteration, not just once during all the time. If I change the setting value through the configuration file should I restart the service for it to be "refreshed" inside or will it be accepted the next time without any interaction from my side?
You need to call ConfigurationManager.RefreshSection method to get the latest values read directly from disk. Here's a simple way to test and provide answer to your question:
static void Main(string[] args)
{
while (true)
{
// There is no need to restart you application to get latest values.
// Calling this method forces the reading of the setting directly from the config.
ConfigurationManager.RefreshSection("appSettings");
Console.WriteLine(ConfigurationManager.AppSettings["myKey"]);
// Or if you're using the Settings class.
Properties.Settings.Default.Reload();
Console.WriteLine(Properties.Settings.Default.MyTestSetting);
// Sleep to have time to change the setting and verify.
Thread.Sleep(10000);
}
}
My app.config containing:
<?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="ConsoleApplication2.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" allowExeDefinition="MachineToLocalUser" requirePermission="false" />
</sectionGroup>
</configSections>
<appSettings>
<add key="myKey" value="Original Value"/>
</appSettings>
<userSettings>
<ConsoleApplication2.Properties.Settings>
<setting name="MyTestSetting" serializeAs="String">
<value>Original Value</value>
</setting>
</ConsoleApplication2.Properties.Settings>
</userSettings>
</configuration>
After you start the application, open the app.config within the build folder, and change the value of the appSetting "myKey". You'll see the new value printed out to the console.
To answer the question, yes they are cached on the first time they are each read I think, and to force the read straight from the disk, you need to refresh the section.
Either when you load it up via the configuration manager (ConfigurationManager.GetSection("x/y");) or when you try to access the properties.
There is a slight grey area here because when you get the configuration out via the config manager:
var config = (MyConfigSection)ConfigurationManager.GetSection("MyConfigSection");
You get a configuration object back if you have provided the configuration section type in the configurationSections element at the top of the config file. If you do not actually provide the actual config you will still get an object back.
However if you have a required field that is not set it will not throw an exception till you call the property. I have worked this out whilst trying to unit test my custom configuration sections.
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);
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()