Dify创建自定义工具，调用ASP.NET Core WebAPI时的注意事项（出现错误：Reached maximum retries (3) for URL ...）

1、要配置Swagger

using Microsoft.AspNetCore.Mvc;using Microsoft.OpenApi.Models;var builder = WebApplication.CreateBuilder(args);builder.Services.AddCors(options =>{    options.AddPolicy("AllowSpecificOrigin",        builder => builder.WithOrigins("http://172.20.10.7:5619") // 替换为你的Dify域名                            .AllowAnyMethod()                            .AllowAnyHeader());});// 添加控制器服务builder.Services.AddControllers();// 配置Swaggerbuilder.Services.AddSwaggerGen(c =>{    c.SwaggerDoc("v1", new OpenApiInfo    {        Title = "PowerApi",        Version = "v1",        Description = "A simple API to calculate powers of a number from 0 to 50.",        Contact = new OpenApiContact        {            Name = "Your Name",            Email = "your.email@example.com",            Url = new System.Uri("https://example.com")        }    });    // 定义Schema    c.MapType<Dictionary<int, double>>(() => new OpenApiSchema    {        Type = "object",        AdditionalProperties = new OpenApiSchema        {            Type = "number"        }    });});var app = builder.Build();if (app.Environment.IsDevelopment()){    app.UseDeveloperExceptionPage();    app.UseSwagger();    app.UseSwaggerUI(c =>    {        c.SwaggerEndpoint("/swagger/v1/swagger.json", "PowerApi v1");        c.DocumentTitle = "PowerApi Documentation";    });}app.UseHttpsRedirection();app.UseStaticFiles();app.UseCookiePolicy();app.Use(async (context, next) =>{    context.Response.Headers.Add("Content-Security-Policy", "script-src 'self';");    await next();});app.UseRouting();app.UseAuthorization();app.UseEndpoints(endpoints =>{    endpoints.MapControllers();});app.Run();

注意：IP地址的部分一定要写对了！不能是localhost或者127.0.0.1

2、launchSettings.json中

{  "$schema": "http://json.schemastore.org/launchsettings.json",  "iisSettings": {    "windowsAuthentication": false,    "anonymousAuthentication": true,    "iisExpress": {      "applicationUrl": "http://localhost:1393",      "sslPort": 44372    }  },  "profiles": {    "http": {      "commandName": "Project",      "dotnetRunMessages": true,      "launchBrowser": true,      "launchUrl": "swagger",      "applicationUrl": "http://172.20.10.7:5169",      "environmentVariables": {        "ASPNETCORE_ENVIRONMENT": "Development"      }    },    "https": {      "commandName": "Project",      "dotnetRunMessages": true,      "launchBrowser": true,      "launchUrl": "swagger",      "applicationUrl": "https://172.20.10.7:7007;http://172.20.10.7:5169",      "environmentVariables": {        "ASPNETCORE_ENVIRONMENT": "Development"      }    },    "IIS Express": {      "commandName": "IISExpress",      "launchBrowser": true,      "launchUrl": "swagger",      "environmentVariables": {        "ASPNETCORE_ENVIRONMENT": "Development"      }    }  }}

注意：IP地址的部分一定要写对了！不能是localhost或者127.0.0.1

using Microsoft.AspNetCore.Mvc;using System;using System.Collections.Generic;namespace PowerApi.Controllers{    [ApiController]    [Route("api/[controller]")]    public class PowerController : ControllerBase    {        [HttpGet("{number}")]        public IActionResult GetPowers(double number)        {            try            {                var powers = new Dictionary<int, double>();                for (int i = 0; i <= 50; i++)                {                    powers[i] = Math.Pow(number, i);                }                // 返回JSON格式的幂运算结果                return Ok(new { powers = powers });            }            catch (Exception ex)            {                return StatusCode(500, $"Internal server error: {ex.Message}");            }        }    }}

3、符合OpenAPI Swagger规范的Schema：

{      "openapi": "3.1.0",      "info": {        "title": "Get weather data",        "description": "Retrieves current weather data for a location.",        "version": "v1.0.0"      },      "servers": [        {          "url": "http://172.20.10.7:5169"        }      ],      "paths": {        "/api/folder": {          "get": {            "description": "Get temperature for a specific location",            "operationId": "GetCurrentWeather",            "deprecated": false          }        }      },      "components": {        "schemas": {}      } }

注意：IP地址的部分一定要写对了！不能是localhost或者127.0.0.1！

4、端口规则，一定要加。

结果：

好了，现在有手有脚了。