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Getting Started with Unary

This tutorial introduces the simple steps to implement a Unary service.

Steps to implement a Unary service​

The following steps are required to define, implement, and use a Unary service.

  • Define a Unary service interface to be shared between the server and client
  • Implement the Unary service interface defined in the server project
  • Call the defined Unary service from the client project

Define a Unary service interface to be shared between the server and client​

Define a Unary service interface in a shared library project (in the case of Unity, use source code copy or file link). The Unary service interface must inherit IService<TSelf>.

The following is an example of a Unary service interface that returns a greeting.

public interface IGreeterService : IService<IGreeterService>
{
    UnaryResult<string> SayHelloAsync(string name, int age);
}

The return type of the method defined in the Unary service must be UnaryResult or UnaryResult<T>. This is a return type specific to Unary services that has a similar meaning to ValueTask, ValueTask<T>.

Implement the Unary service interface defined in the server project​

Implement the Unary service called by the client on the server. The server implementation must inherit ServiceBase<TSelf> and implement the defined Unary service interface.

public class GreeterService : ServiceBase<IGreeterService>, IGreeterService
{
    public async UnaryResult<string> SayHelloAsync(string name, int age)
    {
        return $"Hello {name}! Your age is {age}.";
    }
}

UnaryResult and UnaryResult<T> types can be defined as asynchronous methods (async) like ValueTask, Task, etc.

If the method does not require asynchronous processing, you can also return synchronously using UnaryResult.FromResult or UnaryResult.CompletedResult.

public class GreeterService : ServiceBase<IGreeterService>, IGreeterService
{
    public UnaryResult<string> SayHelloAsync(string name, int age)
    {
        return UnaryResult.FromResult($"Hello {name}! Your age is {age}.");
    }
}

Call the defined Unary service from the client project​

To call the Unary service method from the client, use the MagicOnionClient.Create<T> method.

Create<T> method takes a Unary service interface and a GrpcChannel object as the destination. This method generates a client proxy corresponding to the specified interface. At this point, no request is sent to the server.

var channel = GrpcChannel.ForAddress("https://localhost:5001");
var client = await MagicOnionClient.Create<IGreeterService>(channel, receiver);

Call the method of the Unary service using the generated client proxy.

var result = await client.SayHelloAsync("Alice", 18);
Console.WriteLine(result);