You create a global resource file by putting it in the reserved folder App_GlobalResources at the root of the application. Any .resx file that is in the App_GlobalResources folder has global scope. Additionally, ASP.NET generates a strongly typed object that gives you a simple way to programmatically access global resources.

A local resources file is one that applies to only one ASP.NET page or user control (an ASP.NET file that has a file-name extension of .aspx, .ascx, or .master). You put local resource files in folders that have the reserved name App_LocalResources. Unlike the root App_GlobalResources folder, App_LocalResources folders can be in any folder in the application. You associate a set of resources files with a specific Web page by using the name of the resource file.

For example, if you have a page named Default.aspx in the App_LocalResources folder, you might create the following files:

• Default.aspx.resx. This is the default local resource file (the fallback resource file) if no language match is found.

• Default.aspx.es.resx. This is the resource file for Spanish, without culture information.

• Default.aspx.es-mx.resx. This is the resource file for Spanish (Mexico) specifically.

• Default.aspx.fr.resx. This is the resource file for French, without culture information.

The base name of the file matches the page file name, followed by a language and culture name, and ending with the extension .resx. For a list of culture names, see CultureInfo.

Localization support for ASP.NET AJAX client script builds on the foundation of the ASP.NET 2.0 localization model. In this model, you embed script files and localized script resources in a hub-and-spoke organization of assemblies (satellite assemblies). You can then selectively use these embedded client scripts and resources for specific languages and regions. This model enables a single code base to support multiple cultures. There is also support for localized script files that are provided as .js files on disk. ASP.NET can serve localized client scripts and resources automatically for specific languages and regions.

For more information, see the following topics:

• Localizing Resources for Component Libraries Overview

• Walkthrough: Embedding Localized Resources for a JavaScript File

• Walkthrough: Globalizing a Date by Using Client Script

You can use any combination of global and local resource files in the Web application. Generally, you add resources to a global resource file when you want to share the resources between pages. Resources in global resource files are also strongly typed for when you want to access the files programmatically.

However, global resource files can become large, if you store all localized resources in them. Global resource files can also be more difficult to manage, if more than one developer is working on different pages but in a single resource file.

Local resource files make it easier to manage resources for a single ASP.NET Web page. But you cannot share resources between pages. Additionally, you might create lots of local resource files, if you have many pages that must be localized into many languages. If sites are large with many folders and languages, local resources can quickly expand the number of assemblies in the application domain.

When you make a change to a default resource file, either local or global, ASP.NET recompiles the resources and restarts the ASP.NET application. This can affect the overall performance of your site. If you add satellite resource files, it does not cause a recompilation of resources, but the ASP.NET application will restart.

Note:
Linked resources are supported only in global resource files.

If you have created local resource files for a specific page, you can use implicit localization to fill the property values for a control from the resource file. In implicit localization, ASP.NET reads a resource file and matches resources to property values.

To use implicit localization, you must use a naming convention for resources in the local resource file that uses the following pattern:

Key.Property

For example, if you are creating resources for a Button control named Button1, you might create the following key/value pairs in the local resource file:

Button1.Text
Button1.BackColor
Label1.Text

You can use any name for Key, but Property must match the name of a property of the control that you are localizing.

In the page, you use a special meta attribute in the markup for the control to specify implicit localization. You do not have to explicitly specify which properties are localized. A Button control that is configured for implicit localization might resemble the following:

<asp:Button ID="Button1" runat="server" Text="DefaultText" 
    meta:resourcekey="Button1" />

The resourcekey value matches a key in the corresponding resource file. At run time, ASP.NET matches resources to control properties using the control label as the resourcekey. If a property value is defined in the resource file, ASP.NET substitutes the resource value for the property.

Alternatively, you can use explicit localization, where you use a resource expression. Unlike implicit localization, you must use a resource expression for each property that you want to set.

A Button control that is configured to set the Text property from a global resource file might resemble the following:

<asp:Button ID="Button1" runat="server" 
    Text="<%$ Resources:WebResources, Button1Caption %>" />

The resource expression takes the following form, where Class is optional, unless the resource is a global one, and ResourceID is required:

<%$Resources:Class,ResourceID%>

The Class value identifies the resource file to use when you use global resources. When .resx files are compiled, the base file name, without extensions, is used as the class name of the resulting assembly, explicitly. If you want to use resources from a local resource file (one that matches the current page name), you do not have to include a class name. This is because ASP.NET matches the page class to the resource class.

The ResourceID value is the identifier of the resource to read. In the previous example, the Text property for the button is read from the global resource file WebResources.resx (or the appropriate localized version). In that file, ASP.NET uses the value for the resource with the identifier Button1Caption and for the page itself. To set page properties, you can use resource expressions in the @ Page directive.

You can specify an explicit resource expression or an implicit resource expression for a control, but not both. The following declarative syntax on a Button control causes a parser error:

<asp:Button ID="Button1" 
            runat="server" 
            meta:resourcekey="Button1Resource1"
            Text="<%$ Resources:WebResources, Button1Caption %>" />

In this example, an implicit local resource file (one that matches the current page name) is specified as well as an explicit resource file that is named WebResources. To prevent a parser error for this control, remove one of the resource expressions.

If a page includes static text, you can use ASP.NET localization by including it in a Localize control, and then using explicit localization to set the static text. The Localize control renders no markup; its only function is to act as a placeholder for localized text. The Localize control can be edited in Design view, not only in the property grid. At run time, ASP.NET treats the Localize control as a Literal control. For example, your page might include the following code:

<h1>
  <asp:Localize runat=server 
    ID="WelcomeMessage" 
    Text="Welcome!" meta:resourcekey="LiteralResource1" />
</h1>
<br />
<br />
<asp:Localize runat="server"
    ID="NameCaption"
    Text="Name: " meta:resourcekey="LiteralResource2" />
<asp:TextBox runat="server" ID="TextBox1" 
    meta:resourcekey="TextBox1Resource1" />

Security Note:
This example has a text box that accepts user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview.

In templated controls, such as the DataList, GridView, and Wizard controls, you localize template style properties by accessing the properties through the parent control's implicit resource expression. You cannot use an implicit resource expression on the template itself.

To localize values for a template property, use the meta attribute and a resource key for the control that the template belongs to. Then use either the Property.Subproperty syntax or the Property-Subproperty syntax in the resource file. For example, the following declarative syntax is valid for a Wizard control:

<asp:Wizard ID="Wizard1" 
    runat="server" 
    meta:resourcekey="Wizard1Resource1">
  <NavigationStyle 
    BorderWidth="<%$ resources:navBorderWidth %>"/>
  <WizardSteps>
    <asp:WizardStep ID="WizardStep1" 
      runat="server" 
      Title="Step 1" 
      meta:resourcekey="WizardStep1Resource1">
    </asp:WizardStep>
  </WizardSteps>
</asp:Wizard>

The following key/value pairs in the local resource file could be used for the previous example:

Wizard1Resource1.NavigationStyle.BackColor, Red
navborderWidth, 5

Or the following key/value pairs could be used:

Wizard1Resource1.NavigationStyle-BackColor, Red
navborderWidth, 5

You can use an explicit resource expression for the NavigationStyle property of the Wizard control in the previous example. The explicit resource expression omits the Class name so that resources from a local resource file are used.

For more information about templated server controls, see ASP.NET Web Server Controls Templates.