[c#] 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But it says this is obsolete and that I should use ConfigurationManager which I can't find, even searching in the class view.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?

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()

This also works

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

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.

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()

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.

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.