Best practices for developing world-ready applications
This section describes the best practices to follow when developing world-ready applications.
Globalization best practices
Make your application Unicode internally.
Use the culture-aware classes provided by the System.Globalization namespace to manipulate and format data.
- For sorting, use the SortKey class and the CompareInfo class.
- For string comparisons, use the CompareInfo class.
- For date and time formatting, use the DateTimeFormatInfo class.
- For numeric formatting, use the NumberFormatInfo class.
- For Gregorian and non-Gregorian calendars, use the Calendar class or one of the specific calendar implementations.
Use the culture property settings provided by the System.Globalization.CultureInfo class in the appropriate situations. Use the CultureInfo.CurrentCulture property for formatting tasks, such as date and time or numeric formatting. Use the CultureInfo.CurrentUICulture property to retrieve resources. Note that the
CurrentUICultureproperties can be set per thread.
Enable your application to read and write data to and from a variety of encodings by using the encoding classes in the System.Text namespace. Do not assume ASCII data. Assume that international characters will be supplied anywhere a user can enter text. For example, the application should accept international characters in server names, directories, file names, user names, and URLs.
When using the UTF8Encoding class, for security reasons, use the error detection feature offered by this class. To turn on the error detection feature, create an instance of the class using the constructor that takes a
throwOnInvalidBytesparameter and set the value of this parameter to
Whenever possible, handle strings as entire strings instead of as a series of individual characters. This is especially important when sorting or searching for substrings. This will prevent problems associated with parsing combined characters. You can also work with units of text rather than single characters by using the System.Globalization.StringInfo class.
Display text using the classes provided by the System.Drawing namespace.
For consistency across operating systems, do not allow user settings to override CultureInfo. Use the
CultureInfoconstructor that accepts a
useUserOverrideparameter and set it to
Test your application functionality on international operating system versions, using international data.
If a security decision is based on the result of a string comparison or case change operation, use a culture-insensitive string operation. This practice ensures that the result is not affected by the value of
CultureInfo.CurrentCulture. See the "String Comparisons that Use the Current Culture" section of Best Practices for Using Strings for an example that demonstrates how culture-sensitive string comparisons can produce inconsistent results.
Localization best practices
Move all localizable resources to separate resource-only DLLs. Localizable resources include user interface elements, such as strings, error messages, dialog boxes, menus, and embedded object resources.
Do not hardcode strings or user interface resources.
Do not put non-localizable resources into the resource-only DLLs. This confuses translators.
Do not use composite strings that are built at run time from concatenated phrases. Composite strings are difficult to localize because they often assume an English grammatical order that does not apply to all languages.
Avoid ambiguous constructs such as "Empty Folder" where the strings can be translated differently depending on the grammatical roles of the string components. For example, "empty" can be either a verb or an adjective, which can lead to different translations in languages such as Italian or French.
Avoid using images and icons that contain text in your application. They are expensive to localize.
Allow plenty of room for the length of strings to expand in the user interface. In some languages, phrases can require 50-75 percent more space than they need in other languages.
Use the System.Resources.ResourceManager class to retrieve resources based on culture.
Arrange for professional localization (translation).
For a complete description of creating and localizing resources, see Resources in .NET apps.
Globalization best practices for ASP.NET applications
The following best practices are for ASP.NET Framework apps. For ASP.NET Core apps, see Globalization and localization in ASP.NET Core.
Note that ASP.NET applications are managed applications and therefore can use the same classes as other managed applications for retrieving, displaying, and manipulating information based on culture.
Be aware that you can specify the following three types of encodings in ASP.NET:
requestEncodingspecifies the encoding received from the client's browser.
responseEncodingspecifies the encoding to send to the client browser. In most situations, this encoding should be the same as that specified for
- fileEncoding specifies the default encoding for .aspx, .asmx, and .asax file parsing.
Specify the values for the
uiCultureattributes in the following three places in an ASP.NET application:
- In the globalization section of a Web.config file. This file is external to the ASP.NET application. For more information, see <globalization> element.
- In a page directive. Note that, when an application is in a page, the file has already been read. Therefore, it is too late to specify fileEncoding and requestEncoding. Only
responseEncodingcan be specified in a page directive.
- Programmatically in application code. This setting can vary per request. As with a page directive, by the time the application's code is reached, it is too late to specify
responseEncodingcan be specified in the application code.
Note that the uiCulture value can be set to the browser accept language.