ConfigurationManager Class

Definition

Provides access to configuration files for client applications. This class cannot be inherited.

public static class ConfigurationManager
Inheritance
ConfigurationManager

Examples

The first example shows a simple console application that reads application settings, adds a new setting, and updates an existing setting.

using System;
using System.Configuration;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            ReadAllSettings();
            ReadSetting("Setting1");
            ReadSetting("NotValid");
            AddUpdateAppSettings("NewSetting", "May 7, 2014");
            AddUpdateAppSettings("Setting1", "May 8, 2014");
            ReadAllSettings();
        }

        static void ReadAllSettings()
        {
            try
            {
                var appSettings = ConfigurationManager.AppSettings;

                if (appSettings.Count == 0)
                {
                    Console.WriteLine("AppSettings is empty.");
                }
                else
                {
                    foreach (var key in appSettings.AllKeys)
                    {
                        Console.WriteLine("Key: {0} Value: {1}", key, appSettings[key]);
                    }
                }
            }
            catch (ConfigurationErrorsException)
            {
                Console.WriteLine("Error reading app settings");
            }
        }

        static void ReadSetting(string key)
        {
            try
            {
                var appSettings = ConfigurationManager.AppSettings;
                string result = appSettings[key] ?? "Not Found";
                Console.WriteLine(result);
            }
            catch (ConfigurationErrorsException)
            {
                Console.WriteLine("Error reading app settings");
            }
        }

        static void AddUpdateAppSettings(string key, string value)
        {
            try
            {
                var configFile = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None);
                var settings = configFile.AppSettings.Settings;
                if (settings[key] == null)
                {
                    settings.Add(key, value);
                }
                else
                {
                    settings[key].Value = value;
                }
                configFile.Save(ConfigurationSaveMode.Modified);
                ConfigurationManager.RefreshSection(configFile.AppSettings.SectionInformation.Name);
            }
            catch (ConfigurationErrorsException)
            {
                Console.WriteLine("Error writing app settings");
            }
        }
    }
}

The following example shows how to use a connection string to read data from a database.

using System;
using System.Configuration;
using System.Data.SqlClient;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            ReadProducts();
        }

        static void ReadProducts()
        {
            var connectionString = ConfigurationManager.ConnectionStrings["WingtipToys"].ConnectionString;
            string queryString = "SELECT Id, ProductName FROM dbo.Products;";
            using (var connection = new SqlConnection(connectionString))
            {
                var command = new SqlCommand(queryString, connection);
                connection.Open();
                using (var reader = command.ExecuteReader())
                {
                    while (reader.Read())
                    {
                        Console.WriteLine(String.Format("{0}, {1}", reader[0], reader[1]));
                    }
                }
            }
        }
    }
}

Remarks

The ConfigurationManager class enables you to access machine, application, and user configuration information. This class replaces the ConfigurationSettings class, which is deprecated. For web applications, use the WebConfigurationManager class.

To use the ConfigurationManager class, your project must reference the System.Configuration assembly. By default, some project templates, like Console Application, do not reference this assembly so you must manually reference it.

Nota

The name and location of the application configuration file depend on the application's host. For more information, see Configuring Apps by using Configuration Files.

You can use the built-in System.Configuration types or derive from them to handle configuration information. By using these types, you can work directly with configuration information and you can extend configuration files to include custom information.

The ConfigurationManager class includes members that enable you to perform the following tasks:

Notes to Inheritors

The Configuration class enables programmatic access for editing configuration files. You use one of the Open methods provided by ConfigurationManager. These methods return a Configuration object, which in turn provides the required methods and properties to handle the underlying configuration files. You can access these files for reading or writing.

To read the configuration files, use GetSection(String) or GetSectionGroup(String). The user or process that reads must have the following permissions:

  • Read permission on the configuration file at the current configuration hierarchy level.

  • Read permissions on all the parent configuration files.

If your application needs read-only access to its own configuration, we recommend that you use the GetSection(String) method. This method provides access to the cached configuration values for the current application, which has better performance than the Configuration class.

To write to the configuration files, use one of the Save methods. The user or process that writes must have the following permissions:

  • Write permission on the configuration file and directory at the current configuration hierarchy level.

  • Read permissions on all the configuration files.

Properties

AppSettings

Gets the AppSettingsSection data for the current application's default configuration.

ConnectionStrings

Gets the ConnectionStringsSection data for the current application's default configuration.

Methods

GetSection(String)

Retrieves a specified configuration section for the current application's default configuration.

OpenExeConfiguration(ConfigurationUserLevel)

Opens the configuration file for the current application as a Configuration object.

OpenExeConfiguration(String)

Opens the specified client configuration file as a Configuration object.

OpenMachineConfiguration()

Opens the machine configuration file on the current computer as a Configuration object.

OpenMappedExeConfiguration(ExeConfigurationFileMap, ConfigurationUserLevel, Boolean)

Opens the specified client configuration file as a Configuration object that uses the specified file mapping, user level, and preload option.

OpenMappedExeConfiguration(ExeConfigurationFileMap, ConfigurationUserLevel)

Opens the specified client configuration file as a Configuration object that uses the specified file mapping and user level.

OpenMappedMachineConfiguration(ConfigurationFileMap)

Opens the machine configuration file as a Configuration object that uses the specified file mapping.

RefreshSection(String)

Refreshes the named section so the next time that it is retrieved it will be re-read from disk.

Applies to

Prodotto Versioni
.NET 8 (package-provided), 9 (package-provided)
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7 (package-provided), 4.7, 4.7.1 (package-provided), 4.7.1, 4.7.2 (package-provided), 4.7.2, 4.8 (package-provided), 4.8, 4.8.1
.NET Standard 2.0 (package-provided)
Windows Desktop 3.0, 3.1, 5, 6, 7, 8, 9

See also