Develop Reference

Configuration.SaveAs writes empty config

Getting some odd behavior from Configuration class. This code
class Program
{
static void Main(string[] args)
{
var configFile = AppDomain.CurrentDomain.SetupInformation.ConfigurationFile;
var configuration = ConfigurationManager.OpenExeConfiguration(configFile);
var value = configuration.AppSettings.Settings["Supercali"];
if (value != null) Console.WriteLine("Yay, it finally worked!");
else Console.WriteLine("Still broken.");
configuration.SaveAs("ReadConfig.config");
}
}
with this config in AppDomain.CurrentDomain.SetupInformation.ConfigurationFile:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<startup>
<supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
</startup>
<appSettings>
<add key="Supercali" value="Fragalistic"/>
</appSettings>
</configuration>
writes the following to "ReadConfig.config"
<?xml version="1.0" encoding="utf-8"?>
<configuration>
</configuration>
and prints this
Still broken.
Looking at it in debug view, AppDomain.CurrentDomain.SetupInformation.ConfigurationFile has the correct file, but OpenExeConfiguration seems to create a blank config. The appSettings section is empty. I'm pretty sure this is wrong, but maybe I'm missing something?

Try this:
var configFile = Assembly.GetExecutingAssembly().Location;
var configuration = ConfigurationManager.OpenExeConfiguration(configFile);
var value = configuration.AppSettings.Settings["Supercali"];
if (value != null) Console.WriteLine("Yay, it finally worked!");
else Console.WriteLine("Still broken.");
configuration.SaveAs("ReadConfig.config");
The OpenExeConfiguration expects the path to a DLL/EXE, not to the .config file.

Update nested value in XML

I'm trying to write a routine that updates values in an XML file and believe I'm close. Here's an example of the XML:
<?xml version="1.0" encoding="utf-8"?>
<!-- This file is generated by the GPS_Client program. -->
<Sites>
<Site>
<Id>A</Id>
<add key="landingName" value="Somewhere" />
<add key="landingLat" value="47.423719" />
<add key="landingLon" value="-123.011364" />
<add key="landingAlt" value="36" />
</Site>
<Site>
<Id>B</Id>
<add key="landingName" value="Somewhere Else" />
<add key="landingLat" value="45.629160" />
<add key="landingLon" value="-128.882934" />
<add key="landingAlt" value="327" />
</Site>
</Sites>
The key is that I need to update a specific key without updating the rest of the keys with the same name. Here's the current code:
private void UpdateOrCreateAppSetting(string filename, string site, string key, string value)
{
string path = "\"#" + filename + "\"";
XDocument doc = XDocument.Load(path);
var list = from appNode in doc.Descendants("appSettings").Elements()
where appNode.Attribute("key").Value == key
select appNode;
var e = list.FirstOrDefault();
// If the element doesn't exist, create it
if (e == null) {
new XElement(site,
new XAttribute(key, value));
// If the element exists, just change its value
} else {
e.Element(key).Value = value;
e.Attribute("value").SetValue(value);
}
}
I assume I need to concatenate site, Id and key in some way, but don't see how it's done.

Using this XmlLib, you can have it create the node if it doesn't exist automatically.
private void UpdateOrCreateAppSetting(string filename, string site,
string key, string value)
{
string path = "\"#" + filename + "\"";
XDocument doc = XDocument.Load(path);
XPathString xpath = new XPathString("//Site[Id={0}]/add[#key={1}]", site, key);
XElement node = doc.Root.XPathElement(xpath, true); // true = create if not found
node.Set("value", value, true); // set as attribute, creates attribute if not found
doc.Save(filename);
}

C# ConfigurationManager not returning value

I'm trying to get a value from my configuration file
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<appSettings>
<add key="MusicPath" value="C:/Users/Alvaro/Music" />
</appSettings>
</configuration>
And this is how I handle it
this.config = new ConfigurationHandler();
String musicPath = this.config.MusicPath();
DirectoryInfo dinfo = new DirectoryInfo(musicPath);
And this is the ConfigurationHandler class
namespace RaggaerPlayer.Class
{
class ConfigurationHandler
{
public String MusicPath()
{
String path = ConfigurationManager.AppSettings["MusicPath"];
return path;
}
}
}
But I got an error at the DirectoryInfo variable "Value cannot be null".. what am I doing wrong?

I believe the file should be named App.config. You could rename it, but I think this causes versioning problems.

Can not read Config File

I have a config file in my project, which I am not able to read in for some reason. Similar code has worked for me in the past. I am not sure what am I doing wrong here. I was wondering if someone would be able to have a look and let me know if I am doing something wrong. Please help...
Here's my code:
KeyValueConfigurationCollection settings;
Configuration config;
ExeConfigurationFileMap configFile = new ExeConfigurationFileMap();
configFile.ExeConfigFilename = "myProject.exe.config";
config = ConfigurationManager.OpenMappedExeConfiguration(configFile, ConfigurationUserLevel.None);
settings = config.AppSettings.Settings;
this.logFilePath = settings["logFilePath"].Value;
this.logFilePath = settings["logFileName"].Value;
Here's my Config File:
<?xml version="1.0"?/>
<configuration>
<add key="logFilePath" value=".//Results//" />
<add key="logFileName" value="Output.xml" />
</configuration>
Thanks in advance,
Harit

harit, try amending your structure to:
<?xml version="1.0"?/>
<configuration>
<appSettings>
<add key="logFilePath" value=".//Results//" />
<add key="logFileName" value="Output.xml" />
<appSettings>
</configuration>
Using the ConfigurationManager creates the requirement for this exact structure to be present. it should work as planned with the above change.

The AppSettings Collection is missing from your configuration. You only have the root-level of configured. But you are requesting in your code.
Your configuration should be
<configuration>
<appSettings>
<add key="logFilePath" value=".//Results//" />
<add key="logFileName" value="Output.xml" />
</appSettings>
</configuration>

Read values from different web.config:
ExeConfigurationFileMap fileMap = new ExeConfigurationFileMap();
fileMap.ExeConfigFilename = AppDomain.CurrentDomain.BaseDirectory + #"second.config";
Configuration config = ConfigurationManager.OpenMappedExeConfiguration(fileMap,ConfigurationUserLevel.None);
ConfigurationSection mySection = config.GetSection("countoffiles");
if (config.AppSettings.Settings.Count > 0)
{
System.Configuration.KeyValueConfigurationElement customSetting =
config.AppSettings.Settings["countoffiles"];
if (customSetting != null)
{
Response.Write(customSetting.Value);
}
else
{
Console.WriteLine("No countoffiles application string");
}
}

How to get the values of a ConfigurationSection of type NameValueSectionHandler

I'm working with C#, Framework 3.5 (VS 2008).
I'm using the ConfigurationManager to load a config (not the default app.config file) into a Configuration object.
Using the Configuration class, I was able to get a ConfigurationSection, but I could not find a way to get the values of that section.
In the config, the ConfigurationSection is of type System.Configuration.NameValueSectionHandler.
For what it worth, when I used the method GetSection of the ConfigurationManager (works only when it was on my default app.config file), I received an object type, that I could cast into collection of pairs of key-value, and I just received the value like a Dictionary. I could not do such cast when I received ConfigurationSection class from the Configuration class however.
EDIT:
Example of the config file:
<configuration>
<configSections>
<section name="MyParams"
type="System.Configuration.NameValueSectionHandler" />
</configSections>
<MyParams>
<add key="FirstParam" value="One"/>
<add key="SecondParam" value="Two"/>
</MyParams>
</configuration>
Example of the way i was able to use it when it was on app.config (the "GetSection" method is for the default app.config only):
NameValueCollection myParamsCollection =
(NameValueCollection)ConfigurationManager.GetSection("MyParams");
Console.WriteLine(myParamsCollection["FirstParam"]);
Console.WriteLine(myParamsCollection["SecondParam"]);

Suffered from exact issue. Problem was because of NameValueSectionHandler in .config file. You should use AppSettingsSection instead:
<configuration>
<configSections>
<section name="DEV" type="System.Configuration.AppSettingsSection" />
<section name="TEST" type="System.Configuration.AppSettingsSection" />
</configSections>
<TEST>
<add key="key" value="value1" />
</TEST>
<DEV>
<add key="key" value="value2" />
</DEV>
</configuration>
then in C# code:
AppSettingsSection section = (AppSettingsSection)ConfigurationManager.GetSection("TEST");
btw NameValueSectionHandler is not supported any more in 2.0.

Here's a good post that shows how to do it.
If you want to read the values from a file other than the app.config, you need to load it into the ConfigurationManager.
Try this method: ConfigurationManager.OpenMappedExeConfiguration()
There's an example of how to use it in the MSDN article.

Try using an AppSettingsSection instead of a NameValueCollection. Something like this:
var section = (AppSettingsSection)config.GetSection(sectionName);
string results = section.Settings[key].Value;
Source:
http://social.msdn.microsoft.com/Forums/en-US/csharpgeneral/thread/d5079420-40cb-4255-9b3b-f9a41a1f7ad2/

The only way I can get this to work is to manually instantiate the section handler type, pass the raw XML to it, and cast the resulting object.
Seems pretty inefficient, but there you go.
I wrote an extension method to encapsulate this:
public static class ConfigurationSectionExtensions
{
public static T GetAs<T>(this ConfigurationSection section)
{
var sectionInformation = section.SectionInformation;
var sectionHandlerType = Type.GetType(sectionInformation.Type);
if (sectionHandlerType == null)
{
throw new InvalidOperationException(string.Format("Unable to find section handler type '{0}'.", sectionInformation.Type));
}
IConfigurationSectionHandler sectionHandler;
try
{
sectionHandler = (IConfigurationSectionHandler)Activator.CreateInstance(sectionHandlerType);
}
catch (InvalidCastException ex)
{
throw new InvalidOperationException(string.Format("Section handler type '{0}' does not implement IConfigurationSectionHandler.", sectionInformation.Type), ex);
}
var rawXml = sectionInformation.GetRawXml();
if (rawXml == null)
{
return default(T);
}
var xmlDocument = new XmlDocument();
xmlDocument.LoadXml(rawXml);
return (T)sectionHandler.Create(null, null, xmlDocument.DocumentElement);
}
}
The way you would call it in your example is:
var map = new ExeConfigurationFileMap
{
ExeConfigFilename = #"c:\\foo.config"
};
var configuration = ConfigurationManager.OpenMappedExeConfiguration(map, ConfigurationUserLevel.None);
var myParamsSection = configuration.GetSection("MyParams");
var myParamsCollection = myParamsSection.GetAs<NameValueCollection>();

This is an old question, but I use the following class to do the job. It's based on Scott Dorman's blog:
public class NameValueCollectionConfigurationSection : ConfigurationSection
{
private const string COLLECTION_PROP_NAME = "";
public IEnumerable<KeyValuePair<string, string>> GetNameValueItems()
{
foreach ( string key in this.ConfigurationCollection.AllKeys )
{
NameValueConfigurationElement confElement = this.ConfigurationCollection[key];
yield return new KeyValuePair<string, string>
(confElement.Name, confElement.Value);
}
}
[ConfigurationProperty(COLLECTION_PROP_NAME, IsDefaultCollection = true)]
protected NameValueConfigurationCollection ConfCollection
{
get
{
return (NameValueConfigurationCollection) base[COLLECTION_PROP_NAME];
}
}
The usage is straightforward:
Configuration configuration = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
NameValueCollectionConfigurationSection config =
(NameValueCollectionConfigurationSection) configuration.GetSection("MyParams");
NameValueCollection myParamsCollection = new NameValueCollection();
config.GetNameValueItems().ToList().ForEach(kvp => myParamsCollection.Add(kvp));

Here are some examples from this blog mentioned earlier:
<configuration>
<Database>
<add key="ConnectionString" value="data source=.;initial catalog=NorthWind;integrated security=SSPI"/>
</Database>
</configuration>
get values:
NameValueCollection db = (NameValueCollection)ConfigurationSettings.GetConfig("Database");
labelConnection2.Text = db["ConnectionString"];
-
Another example:
<Locations
ImportDirectory="C:\Import\Inbox"
ProcessedDirectory ="C:\Import\Processed"
RejectedDirectory ="C:\Import\Rejected"
/>
get value:
Hashtable loc = (Hashtable)ConfigurationSettings.GetConfig("Locations");
labelImport2.Text = loc["ImportDirectory"].ToString();
labelProcessed2.Text = loc["ProcessedDirectory"].ToString();

Try this;
Credit: https://www.limilabs.com/blog/read-system-net-mailsettings-smtp-settings-web-config
SmtpSection section = (SmtpSection)ConfigurationManager.GetSection("system.net/mailSettings/smtp");
string from = section.From;
string host = section.Network.Host;
int port = section.Network.Port;
bool enableSsl = section.Network.EnableSsl;
string user = section.Network.UserName;
string password = section.Network.Password;

This works like a charm
dynamic configSection = ConfigurationManager.GetSection("MyParams");
var theValue = configSection["FirstParam"];