ASP.NET Core 7 Minimal API默认不跳转Swagger问题求助

我们开发了一个ASP.NET Core 7 Minimal API应用，启动后未自动跳转至Swagger界面，反而出现“Localhost not found”错误；但在URL末尾添加/swagger路径后，Swagger可正常打开。请问要设置默认打开Swagger，是否遗漏了相关配置？

以下是当前program.cs代码：

using Dapr.Client;
using ErpInterfaceService.Abstractions;
using ErpInterfaceService.Data;
using ErpInterfaceService.Models;
using Microsoft.EntityFrameworkCore;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddEndpointDefinitions(typeof(Message));
builder.Services.AddHealthChecks();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

// TODO: Move this connection string to a secrets store. 
builder.Services.AddDbContext<ErpInterfaceContext>(options =>
    options.UseSqlServer(builder.Configuration.GetConnectionString("ErpInterface")));

builder.Services.AddSingleton(new DaprClientBuilder().Build());

var app = builder.Build();

// Apply any new migrations to the database
using (var scope = app.Services.CreateScope())
{
    var dbContext = scope.ServiceProvider.GetRequiredService<ErpInterfaceContext>();
    dbContext.Database.Migrate();
}

if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseEndpointDefinitions();
app.MapHealthChecks("/health");

app.Run();

解决方案 #

你需要添加两个关键配置之一（或两者结合）来实现启动自动跳转Swagger：

方法1：配置SwaggerUI默认路由跳转 #

在UseSwaggerUI中添加配置，让根路径/自动重定向到Swagger界面：

if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI(options =>
    {
        // 设置根路径直接指向Swagger文档页面
        options.RoutePrefix = string.Empty;
        options.SwaggerEndpoint("/swagger/v1/swagger.json", "ErpInterfaceService API V1");
    });
}

方法2：修改launchSettings.json设置启动URL #

找到项目中的Properties/launchSettings.json，修改launchUrl字段，指定启动时直接打开/swagger：

{
  "profiles": {
    "http": {
      "commandName": "Project",
      "dotnetRunMessages": true,
      "launchBrowser": true,
      "launchUrl": "swagger",
      "applicationUrl": "http://localhost:5000",
      "environmentVariables": {
        "ASPNETCORE_ENVIRONMENT": "Development"
      }
    }
  }
}

修改后的完整program.cs示例 #

using Dapr.Client;
using ErpInterfaceService.Abstractions;
using ErpInterfaceService.Data;
using ErpInterfaceService.Models;
using Microsoft.EntityFrameworkCore;

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddEndpointDefinitions(typeof(Message));
builder.Services.AddHealthChecks();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

// TODO: Move this connection string to a secrets store. 
builder.Services.AddDbContext<ErpInterfaceContext>(options =>
    options.UseSqlServer(builder.Configuration.GetConnectionString("ErpInterface")));

builder.Services.AddSingleton(new DaprClientBuilder().Build());

var app = builder.Build();

// Apply any new migrations to the database
using (var scope = app.Services.CreateScope())
{
    var dbContext = scope.ServiceProvider.GetRequiredService<ErpInterfaceContext>();
    dbContext.Database.Migrate();
}

if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI(options =>
    {
        options.RoutePrefix = string.Empty;
        options.SwaggerEndpoint("/swagger/v1/swagger.json", "ErpInterfaceService API V1");
    });
}

app.UseEndpointDefinitions();
app.MapHealthChecks("/health");

app.Run();

内容的提问来源于stack exchange，提问作者John Swaringen