ASP.NET Core中Swagger持续加载但无法获取数据

运行项目时Swagger一直处于加载状态，无法获取接口数据，项目基于.NET 6+框架，所有配置均写在Program.cs中，代码如下：

using Microsoft.EntityFrameworkCore;
using Package.Interfaces;
using Package.Models;

var builder = WebApplication.CreateBuilder(args);

// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();


var connectionString = builder.Configuration.GetConnectionString("DefaultConnection");
builder.Services.AddDbContext<OperationsContext>(x => x.UseSqlServer(connectionString));

builder.Services.AddScoped<IContentRepository, ContentRepository>();
builder.Services.AddScoped<IPackageRepository, PackageRepository>();

var app = builder.Build();


if (app.Environment.IsDevelopment())
{
    app.UseDeveloperExceptionPage();

    // Enable middleware to serve generated Swagger as a JSON endpoint.
    app.UseSwagger();
    app.UseSwaggerUI(c =>
    {
        c.SwaggerEndpoint("v1/swagger.json", "MyAPI V1");
    });
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
    endpoints.MapControllers();
});
app.Run();

排查与解决步骤： #

• 修正Swagger端点路径
  当前配置的c.SwaggerEndpoint("v1/swagger.json", "MyAPI V1")可能存在路径匹配问题，直接在浏览器访问https://localhost:{你的端口}/v1/swagger.json，如果返回404，说明路径错误。修改为根相对路径：

  c.SwaggerEndpoint("/v1/swagger.json", "MyAPI V1");
  

• 调整中间件顺序
  .NET 6+中间件执行顺序严格，确保Swagger相关中间件在UseHttpsRedirection之前加载，同时可以简化控制器映射写法：

  if (app.Environment.IsDevelopment())
  {
      app.UseDeveloperExceptionPage();
      app.UseSwagger();
      app.UseSwaggerUI(c =>
      {
          c.SwaggerEndpoint("/v1/swagger.json", "MyAPI V1");
      });
  }
  app.UseHttpsRedirection();
  app.UseStaticFiles();
  app.UseRouting();
  app.UseAuthorization();
  // 替代原UseEndpoints写法
  app.MapControllers();
  

• 检查控制器路由配置
  确保所有Controller都标记了[ApiController]和路由属性（比如[Route("api/[controller]")]），没有正确路由的控制器无法被Swagger扫描到。

• 验证Swagger JSON可访问性
  启动项目后，手动访问/v1/swagger.json，如果能正常返回JSON数据，说明Swagger生成正常，问题出在UI端路径；如果返回错误，检查是否有中间件拦截（比如认证、授权中间件）或服务配置错误。

修改后的完整Program.cs示例： #

using Microsoft.EntityFrameworkCore;
using Package.Interfaces;
using Package.Models;

var builder = WebApplication.CreateBuilder(args);

// 配置控制器与Swagger服务
builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

// 数据库上下文配置
var connectionString = builder.Configuration.GetConnectionString("DefaultConnection");
builder.Services.AddDbContext<OperationsContext>(x => x.UseSqlServer(connectionString));

// 注册仓储服务
builder.Services.AddScoped<IContentRepository, ContentRepository>();
builder.Services.AddScoped<IPackageRepository, PackageRepository>();

var app = builder.Build();

// 开发环境启用Swagger
if (app.Environment.IsDevelopment())
{
    app.UseDeveloperExceptionPage();
    app.UseSwagger();
    app.UseSwaggerUI(c =>
    {
        c.SwaggerEndpoint("/v1/swagger.json", "MyAPI V1");
        // 可选：设置默认展开所有接口文档
        c.DocExpansion(Swashbuckle.AspNetCore.SwaggerUI.DocExpansion.List);
    });
}

app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthorization();

// 映射控制器路由
app.MapControllers();

app.Run();

内容的提问来源于stack exchange，提问作者smbbb