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Swagger
builder.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Schemac.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。