IResourceProvider Interface

IResourceProvider Interface

 

Defines the interface a class must implement to act as a resource provider.

Namespace:   System.Web.Compilation
Assembly:  System.Web (in System.Web.dll)

public interface IResourceProvider

NameDescription
System_CAPS_pubpropertyResourceReader

Gets an object to read resource values from a source.

NameDescription
System_CAPS_pubmethodGetObject(String, CultureInfo)

Returns a resource object for the key and culture.

A resource provider facilitates the retrieving of values from a resource file. When an expression of the form <%$ Resources: classKey, resourceKey %> is encountered during page parsing, the resource provider returns the localized value for the resource. The ResourceProviderFactory class creates instances of IResourceProvider objects for use in retrieving the values.

The following code example shows a customized resource provider factory that retrieves cached values. The resource provider factory creates an instance of a class that implements IResourceProvider.

[
    DesignTimeResourceProviderFactoryAttribute(
        typeof(CustomDesignTimeResourceProviderFactory))
]
public class CustomResourceProviderFactory : ResourceProviderFactory
{
    public override IResourceProvider
      CreateGlobalResourceProvider(string classname)
    {
        return new CustomResourceProvider(null, classname);
    }
    public override IResourceProvider
      CreateLocalResourceProvider(string virtualPath)
    {
        return new CustomResourceProvider(virtualPath, null);
    }
}

// Define the resource provider for global and local resources.
internal class CustomResourceProvider : IResourceProvider
{
    string _virtualPath;
    string _className;

    public CustomResourceProvider(string virtualPath, string classname)
    {
        _virtualPath = virtualPath;
        _className = classname;
    }

    private IDictionary GetResourceCache(string culturename)
    {
        return (IDictionary)
            System.Web.HttpContext.Current.Cache[culturename];
    }

    object IResourceProvider.GetObject
        (string resourceKey, CultureInfo culture)
    {
        object value;

        string cultureName = null;
        if (culture != null)
        {
            cultureName = culture.Name;
        }
        else
        {
            cultureName = CultureInfo.CurrentUICulture.Name;
        }

        value = GetResourceCache(cultureName)[resourceKey];
        if (value == null)
        {
            value = GetResourceCache(null)[resourceKey];
        }
        return value;
    }


    IResourceReader IResourceProvider.ResourceReader
    {
        get
        {
            string cultureName = null;
            CultureInfo currentUICulture = CultureInfo.CurrentUICulture;
            if (!String.Equals(currentUICulture.Name,
                CultureInfo.InstalledUICulture.Name))
            {
                cultureName = currentUICulture.Name;
            }

            return new CustomResourceReader
                (GetResourceCache(cultureName));
        }
    }
}


internal sealed class CustomResourceReader : IResourceReader
{
    private IDictionary _resources;

    public CustomResourceReader(IDictionary resources)
    {
        _resources = resources;
    }

    IDictionaryEnumerator IResourceReader.GetEnumerator()
    {
        return _resources.GetEnumerator();
    }

    void IResourceReader.Close() { }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return _resources.GetEnumerator();
    }

    void IDisposable.Dispose() { return; }
}

.NET Framework
Available since 2.0
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