MediatR 13.0.0
MediatR
Simple mediator implementation in .NET
In-process messaging with no dependencies.
Supports request/response, commands, queries, notifications and events, synchronous and async with intelligent dispatching via C# generic variance.
Examples in the wiki.
Installing MediatR
You should install MediatR with NuGet:
Install-Package MediatR
Or via the .NET Core command line interface:
dotnet add package MediatR
Either commands, from Package Manager Console or .NET Core CLI, will download and install MediatR and all required dependencies.
Using Contracts-Only Package
To reference only the contracts for MediatR, which includes:
IRequest(including generic variants)INotificationIStreamRequest
Add a package reference to MediatR.Contracts
This package is useful in scenarios where your MediatR contracts are in a separate assembly/project from handlers. Example scenarios include:
- API contracts
- GRPC contracts
- Blazor
Registering with IServiceCollection
MediatR supports Microsoft.Extensions.DependencyInjection.Abstractions directly. To register various MediatR services and handlers:
services.AddMediatR(cfg => cfg.RegisterServicesFromAssemblyContaining<Startup>());
or with an assembly:
services.AddMediatR(cfg => cfg.RegisterServicesFromAssembly(typeof(Startup).Assembly));
This registers:
IMediatoras transientISenderas transientIPublisheras transientIRequestHandler<,>concrete implementations as transientIRequestHandler<>concrete implementations as transientINotificationHandler<>concrete implementations as transientIStreamRequestHandler<>concrete implementations as transientIRequestExceptionHandler<,,>concrete implementations as transientIRequestExceptionAction<,>)concrete implementations as transient
This also registers open generic implementations for:
INotificationHandler<>IRequestExceptionHandler<,,>IRequestExceptionAction<,>
To register behaviors, stream behaviors, pre/post processors:
services.AddMediatR(cfg => {
cfg.RegisterServicesFromAssembly(typeof(Startup).Assembly);
cfg.AddBehavior<PingPongBehavior>();
cfg.AddStreamBehavior<PingPongStreamBehavior>();
cfg.AddRequestPreProcessor<PingPreProcessor>();
cfg.AddRequestPostProcessor<PingPongPostProcessor>();
cfg.AddOpenBehavior(typeof(GenericBehavior<,>));
});
With additional methods for open generics and overloads for explicit service types.
Setting the license key
You can set the license key when registering MediatR:
services.AddMediatR(cfg =>
{
cfg.LicenseKey = "<license key here>";
})
You can register for your license key at MediatR.io