Dependency Static Class

[namespace: Serenity.Abstractions, assembly: Serenity.Core]

Dependency class is the service locator of Serenity. All dependencies are queried through its methods:

public static class Dependency
{
    public static TType Resolve<TType>() where TType : class;
    public static TType Resolve<TType>(string name) where TType : class;
    public static TType TryResolve<TType>() where TType : class;
    public static TType TryResolve<TType>(string name) where TType : class;
    public static IDependencyResolver SetResolver(IDependencyResolver value);
    public static IDependencyResolver Resolver { get; }
    public static bool HasResolver { get; }
}

In your application’s start method (e.g. in global.asax.cs) you should initialize service locator by setting a dependency resolver (IDependencyResolver) implementation (an IoC container) with SetResolver method.

Dependency.SetResolver Method

Configures the dependency resolver implementation to use.

You can use IoC container of your choice but Serenity already includes one based on Munq:

var container = new MunqContainer();
Dependency.SetResolver(container);

SetResolver methods return previously configured IDependencyResolver implementation, or null if none is configured before.

Dependency.Resolver Property

Returns currently configured IDependencyResolver implementation.

Throws a InvalidProgramException if none is configured yet.

Depency.HasResolver Property

Returns true if a IDependencyResolver implementation is configured through SetResolver. Returns false, if not.

Dependency.Resolve Method

Returns the registered implementation for requested type.

If no implementation is registered, throws a KeyNotFoundException.

If no dependency resolver is configured yet, throw a InvalidProgramException

Second overload of Resolve method accepts a name parameter. This should be used if different providers are registered for an interface depending on scope.

For example, Serenity has a IConfigurationRepository interface that can have different providers based on setting scope. Some settings might be Application scoped (shared between all servers for this application), while some might be Server scoped (each server might use a different unique identifier).

So, to retrieve a IConfigurationRepository provider for each of these scopes, you would call the method like:

var appConfig = Dependency.Resolve<IConfigurationRepository>("Application");
var srvConfig = Dependency.Resolve<IConfigurationRepository>("Server");

Dependency.TryResolve Method

This is functionally equivalent to Resolve method with one difference.

If a provider is not registered for requested type, or no dependency resolver is configured yet, TryResolve doesn’t throw an exception, but instead returns null.