ResourceManager Class

Provides convenient access to culture-specific resources at runtime.

Namespace: System.Resources
Assembly: mscorlib (in mscorlib.dll)

public class ResourceManager
/** @attribute SerializableAttribute() */ 
/** @attribute ComVisibleAttribute(true) */ 
public class ResourceManager
public class ResourceManager

The ResourceManager class looks up culture-specific resources, provides resource fallback when a localized resource does not exist, and supports resource serialization.

Using the methods of ResourceManager, a caller can access the resources for a particular culture using the GetObject and GetString methods. By default, these methods return the resource for the culture determined by the current cultural settings of the thread that made the call. (See Thread.CurrentUICulture for more information.) A caller can use the ResourceManager.GetResourceSet method to obtain a ResourceSet, which represents the resources for a particular culture, ignoring culture fallback rules. You can then use the ResourceSet to access the resources, localized for that culture, by name.

Ideally, you should create resources for every language, or at least a meaningful subset of the language. The resource file names follow the naming convention basename.cultureName.resources, where basename is the name of the application or the name of a class, depending on the level of detail you want. The CultureInfo 's Name property is used to determine the cultureName. A resource for the neutral culture (returned by InvariantCulture) should be named basename.resources.

For example, suppose that an assembly has several resources in a resource file with the basename "MyResources". These resource files will have names such as "MyResources.ja-JP.resources", "", "MyResources.zh-CHS.resources", or "", which contain resources respectively for Japanese, German, simplified Chinese, and French (Belgium). The default resource file should be named MyResources.resources. The culture-specific resource files are commonly packaged in satellite assemblies for each culture. The default resource file should be in your main assembly.

Now suppose that a ResourceManager has been created to represent the resources with this basename. Using the ResourceManager, you can obtain a ResourceSet that encapsulates "MyResources.ja-JP.resources" by calling GetResourceSet(new CultureInfo ("ja-JP"), TRUE, FALSE). Or, if you know that "MyResources" contains a resource named "TOOLBAR_ICON", you can obtain the value of that resource localized for Japan by calling GetObject("TOOLBAR_ICON", new CultureInfo("ja-JP")).

While not strictly necessary for the most basic uses of the ResourceManager, publicly shipping assemblies should use the SatelliteContractVersionAttribute to support versioning your main assembly without redeploying your satellites, and the NeutralResourcesLanguageAttribute to avoid looking up a satellite assembly that might never exist.

For more information about versioning support for satellite assemblies, see Retrieving Resources in Satellite Assemblies. To learn more about creating satellite assemblies, see Creating Satellite Assemblies. For assistance with localization of Windows Forms dialogs, see the Windows Forms Resource Editor (Winres.exe) tool in the Microsoft .NET Framework SDK.

To learn more about setting up and creating resources, see Resources in Applications.

Caution noteCaution

Using standalone .resources files in an ASP.NET application will break XCOPY deployment, because the resources remain locked until they are explicitly released by the ReleaseAllResources method. If you want to deploy resources into ASP.NET applications, you should compile your .resources into satellite assemblies.

Caution noteCaution

Resources marked as private are accessible only in the assembly in which they are placed. Because a satellite assembly contains no code, resources private to it become unavailable through any mechanism. Therefore, resources in satellite assemblies should always be public so that they are accessible from your main assembly. Resources embedded in your main assembly are accessible to your main assembly, whether private or public.

<satelliteassemblies> Configuration File Node

You can create a <satelliteassemblies> node in the application configuration file to specify that you have deployed a specific set of cultures for your application, and that the ResourceManager class should not attempt to probe for any culture that is not listed in that node.


The preferred alternative to creating a <satelliteassemblies> node is to use the ClickOnce Deployment Manifest feature.

Create a configuration file section similar to the following code example:

<?xml version ="1.0"?>
        <assembly name="MainAssemblyName, Version=versionNumber, Culture=neutral, PublicKeyToken=null|yourPublicKeyToken">

In your configuration file, do the following:

  • Specify one or more <assembly> nodes for each main assembly that you deploy, where the <assembly> node attribute specifies a fully qualified assembly name. Specify the name of your main assembly in place of MainAssemblyName, and specify the Version, PublicKeyToken, and Culture attribute values that correspond to your main assembly.

    For the Version attribute, specify the version number of your assembly. For example, the first release of your assembly might be version number

    For the PublicKeyToken attribute, specify the keyword "null" if you have not signed your assembly with a strong name, or specify your public key token if you have signed your assembly.

    For the Culture attribute, specify the keyword "neutral" to designate the main assembly and cause the ResourceManager class to probe only for the cultures listed in the <culture> nodes.

    For more information about fully qualified assembly names, see Assembly Names. For more information about strong-named assemblies, see Creating and Using Strong-Named Assemblies.

  • Specify one or more <culture> nodes with a specific culture name, such as "fr-FR", or a neutral culture name, such as "fr".

If resources are needed for any assembly not listed under the <satelliteassemblies> node, the ResourceManager class probes for cultures using standard probing rules.

The following code example demonstrates using an explicit culture and the implicit current UI culture to obtain string resources from a main assembly and a satellite assembly. For more information, see the "Directory Locations for Satellite Assemblies Not Installed in the Global Assembly Cache" subtopic of the Creating Satellite Assemblies topic.

// This code example demonstrates the ResourceManager() 
// constructor and ResourceManager.GetString() method.

using System;
using System.Resources;
using System.Reflection;
using System.Threading;
using System.Globalization;

Perform the following steps to use this code example:

Main assembly:
1) In a main directory, create a file named "rmc.txt" that 
contains the following resource strings:

holiday="Cinco de Mayo"

2) Use the resgen.exe tool to generate the "rmc.resources" 
resource file from the "rmc.txt" input file.

> resgen rmc.txt

Satellite Assembly:
3) Create a subdirectory of the main directory and name the 
subdirectory "es-ES", which is the culture name of the 
satellite assembly.

4) Create a file named "" that contains the 
following resource strings:

holiday="Cinco de Mayo"

5) Use the resgen.exe tool to generate the "" 
resource file from the "" input file.

> resgen

6) Use the al.exe tool to create a satellite assembly. If the 
base name of the application is "rmc", the satellite assembly 
name must be "rmc.resources.dll". Also, specify the culture, 
which is es-ES.

> al / /c:es-ES /out:rmc.resources.dll 

7) Assume the filename for this code example is "rmc.cs". Compile 
rmc.cs and embed the main assembly resource file, rmc.resources, in 
the executable assembly, rmc.exe:

>csc /res:rmc.resources rmc.cs

8) Execute rmc.exe, which obtains and displays the embedded 
resource strings.

class Sample 
    public static void Main() 
    string day;
    string year;
    string holiday;
    string celebrate = "{0} will occur on {1} in {2}.\n";

// Create a resource manager. The GetExecutingAssembly() method
// gets rmc.exe as an Assembly object.

    ResourceManager rm = new ResourceManager("rmc", 

// Obtain resources using the current UI culture.
    Console.WriteLine("Obtain resources using the current UI culture.");

// Get the resource strings for the day, year, and holiday 
// using the current UI culture. Use those strings to 
// display a message.

    day  = rm.GetString("day");
    year = rm.GetString("year");
    holiday = rm.GetString("holiday");
    Console.WriteLine(celebrate, holiday, day, year);

// Obtain the es-ES culture.
    CultureInfo ci = new CultureInfo("es-ES");

// Get the resource strings for the day, year, and holiday 
// using the specified culture. Use those strings to 
// display a message. 

// Obtain resources using the es-ES culture.
    Console.WriteLine("Obtain resources using the es-ES culture.");

    day  = rm.GetString("day", ci);
    year = rm.GetString("year", ci);
    holiday = rm.GetString("holiday", ci);

// ---------------------------------------------------------------
// Alternatively, comment the preceding 3 code statements and 
// uncomment the following 4 code statements:
// ----------------------------------------------------------------

// Set the current UI culture to "es-ES" (Spanish-Spain).
//    Thread.CurrentThread.CurrentUICulture = ci;

// Get the resource strings for the day, year, and holiday 
// using the current UI culture. Use those strings to 
// display a message. 
//    day  = rm.GetString("day");
//    year = rm.GetString("year");
//    holiday = rm.GetString("holiday");
// ---------------------------------------------------------------

// Regardless of the alternative that you choose, display a message 
// using the retrieved resource strings.
    Console.WriteLine(celebrate, holiday, day, year);

This code example produces the following results:

Obtain resources using the current UI culture.
"5th of May" will occur on Friday in 2006.

Obtain resources using the es-ES culture.
"Cinco de Mayo" will occur on Viernes in 2006.


This type is safe for multithreaded operations.

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0