Implement endpoints with Services Dependency Injection.

**Note: This implementation is not in minimalAPI way and not optimized, expected to be changed soon.**

Add: `UserService` and its interface `IUserService`.

Fix: `UserEndpoint` is now in instance class style with DI to work.

Fix: change main program to work with above design.

OptixServe.Api/Endpoints/UserEndpoint.cs

@@ -1,4 +1,5 @@
 using System.Text.Json.Serialization;
+using OptixServe.Core.Services;
 using OptixServe.Api.Dtos;
 
 namespace OptixServe.Api.Endpoints;
@@ -8,25 +9,37 @@ namespace OptixServe.Api.Endpoints;
 [JsonSerializable(typeof(IEnumerable<UserDto>))]
 public partial class UserJsonContext : JsonSerializerContext { }
 
-public static class UserEndpoint
+public class UserEndpoint
 {
-    public static IEnumerable<UserDto> GetUsers()
+    private readonly IUserService _userService;
+
+    // 通过构造函数注入依赖
+    public UserEndpoint(IUserService userService)
     {
-        return [
-            new() {Id="1234", UserName = "xxx"},
-            new() {Id="5678", UserName = "yyy"},
-        ];
+        _userService = userService;
     }
 
     public static void Register(WebApplication app)
     {
         var group = app.MapGroup("/users");
 
-        group.MapGet("/", GetAllUsers);
+        group.MapGet("/", (UserEndpoint endpoint) => endpoint.GetAllUsers());
+        group.MapGet("/{id}", (string id, UserEndpoint endpoint) => endpoint.GetUserById(id));
     }
 
-    public static IResult GetAllUsers()
+    public IResult GetAllUsers()
     {
-        return Results.Ok(GetUsers());
+        var users = _userService.GetUsers()
+            .Select(u => new UserDto { Id = u.Id, UserName = u.UserName });
+        return Results.Ok(users);
+    }
+
+    public IResult GetUserById(string id)
+    {
+        var user = _userService.GetUserById(id);
+        if (user == null)
+            return Results.NotFound();
+
+        return Results.Ok(new UserDto { Id = user.Id, UserName = user.UserName });
     }
 }

OptixServe.Api/Program.cs

@@ -1,5 +1,6 @@
 using System.CommandLine;
 using OptixServe.Api.Endpoints;
+using OptixServe.Core.Services;
 
 class Program
 {
@@ -41,6 +42,7 @@ class Program
             var configFile = parseResult.GetValue(configOption);
             builder.AddConfigurationWithCommand(configFile);
 
+            builder.RegisterServices();
             builder.RegiserJsonContext();
 
             var app = builder.Build();
@@ -61,27 +63,6 @@ class Program
 /// </summary>
 static class ExtensionMethods
 {
-    /// <summary>
-    /// Registers all API endpoints
-    /// </summary>
-    /// <param name="app">WebApplication instance</param>
-    public static void RegisterEndpoints(this WebApplication app)
-    {
-        UserEndpoint.Register(app);
-    }
-
-    /// <summary>
-    /// Configures JSON serialization options with custom context
-    /// </summary>
-    /// <param name="builder">WebApplicationBuilder instance</param>
-    public static void RegiserJsonContext(this WebApplicationBuilder builder)
-    {
-        builder.Services.ConfigureHttpJsonOptions(options =>
-        {
-            options.SerializerOptions.TypeInfoResolverChain.Add(UserJsonContext.Default);
-        });
-    }
-
     /// <summary>
     /// Adds configuration sources to the application builder
     /// </summary>
@@ -105,4 +86,39 @@ static class ExtensionMethods
 
         builder.Configuration.AddConfiguration(configurationBuilder.Build());
     }
+
+    /// <summary>
+    /// Configures JSON serialization options with custom context
+    /// </summary>
+    /// <param name="builder">WebApplicationBuilder instance</param>
+    public static void RegiserJsonContext(this WebApplicationBuilder builder)
+    {
+        builder.Services.ConfigureHttpJsonOptions(options =>
+        {
+            options.SerializerOptions.TypeInfoResolverChain.Add(UserJsonContext.Default);
+        });
+    }
+
+    /// <summary>
+    /// Configures services for DI
+    /// </summary>
+    /// <param name="builder"></param>
+    public static void RegisterServices(this WebApplicationBuilder builder)
+    {
+        // Application services
+        builder.Services.AddScoped<IUserService, UserService>();
+
+        // WebAPI Endpoint services
+        builder.Services.AddScoped<UserEndpoint>();
+    }
+
+    /// <summary>
+    /// Registers all API endpoints
+    /// </summary>
+    /// <param name="app">WebApplication instance</param>
+    public static void RegisterEndpoints(this WebApplication app)
+    {
+        UserEndpoint.Register(app);
+    }
+
 }

OptixServe.Core/Services/UserService.cs

@@ -0,0 +1,25 @@
+using OptixServe.Core.Models;
+
+namespace OptixServe.Core.Services;
+
+public interface IUserService
+{
+    IEnumerable<User> GetUsers();
+    User? GetUserById(string Id);
+}
+
+public class UserService : IUserService
+{
+    public User? GetUserById(string Id)
+    {
+        throw new NotImplementedException();
+    }
+
+    public IEnumerable<User> GetUsers()
+    {
+        return [
+            new() { Id = "1234", UserName = "xxx", Password = "pass1" },
+            new() { Id = "5678", UserName = "yyy", Password = "pass2" }
+        ];
+    }
+}