背景
WebAPI 插件热插拔是指在不重启应用程序的情况下，能够动态地加载、更新或卸载功能模块（即插件）的能力。这种设计模式在软件开发中非常有用，尤其是在需要频繁更新或扩展功能的大型系统中。通过实现插件架构，可以将系统的不同部分解耦，使得它们可以独立开发、测试和部署。
对于WebAPI来说，这意味着服务端可以在运行时根据业务需求灵活调整其提供的API接口和服务逻辑，而无需担心每次修改都要重新启动整个应用，从而减少停机时间，提高系统的稳定性和灵活性。
程序演示
我们启动程序通过调用动态接口使用插件的增删改查等功能；，其中带{DynamicParam}的是你要使用的插件的名称；{funName}是你要使用插件的接口名称。
程序运行界面
查询筛选接口
使用postman 进行查询筛选博客操作
插件新增接口
插件的新增博客接口，然后看数据库变化
插件更新接口
插件的更新博客接口
插件删除接口
插件上传文件接口
代码实现
前提准备
需要安装nuget程序包：Newtonsoft.Json，SqlSugarCore。方便我们做类型转换和数据存储的相关功能；
1，首先我们创建一个webapi 的项目，然后定义一个插件IPluginDllApi.cs的接口（后续新增的类库需要继承用）
using Microsoft.AspNetCore.Mvc;
namespace DynamicPluginApiDemo.Utils
{
public interface IPluginDllApi
{
string Name { get; }
IActionResult GetRequest(string funName, Dictionary<string, string> queryParameters);
IActionResult PostRequestForm(string funName, Dictionary<string, string> queryParameters, IFormCollection formData);
IActionResult PostRequestBody(string funName, Dictionary<string, string> queryParameters, object jsonData);
}
}
2，创建一个插件帮助类和数据库帮助类。
using SqlSugar;
namespace DynamicPluginApiDemo.Utils
{
public static class DbHelper
{
public static SqlSugarClient Db;
static DbHelper()
{
if (Db == null)
//创建数据库对象 (用法和EF Dappper一样通过new保证线程安全)
Db = new SqlSugarClient(new ConnectionConfig()
{
ConnectionString = "server=192.168.1.61;Database=testdb;Uid=root;Pwd=MyNewPass@123;SslMode=None;AllowPublicKeyRetrieval=true;",
DbType = SqlSugar.DbType.MySql,
IsAutoCloseConnection = true
},
db =>
{
db.Aop.OnLogExecuting = (sql, pars) =>
{
//获取原生SQL推荐 5.1.4.63 性能OK
Console.WriteLine(UtilMethods.GetNativeSql(sql, pars));
};
});
}
}
}
using System.Runtime.Loader;
namespace DynamicPluginApiDemo.Utils
{
public class PluginDllHelper
{
public static List<IPluginDllApi> _labPlugins = new List<IPluginDllApi>();
private static string _pluginFolder = Path.Combine(Directory.GetCurrentDirectory(), "Plugins");
/// <summary>
/// 重新加载
/// </summary>
public static void ReLoadDll()
{
if (!Directory.Exists(_pluginFolder))
Directory.CreateDirectory(_pluginFolder);
_labPlugins = new List<IPluginDllApi>();
foreach (var dllPath in Directory.GetFiles(_pluginFolder, "*.dll"))
{
try
{
var assemblyLoadContext = new AssemblyLoadContext(Path.GetFileNameWithoutExtension(dllPath), true);
var assembly = assemblyLoadContext.LoadFromAssemblyPath(dllPath);
var pluginTypes = assembly.GetTypes()
.Where(t => typeof(IPluginDllApi).IsAssignableFrom(t) && !t.IsInterface && !t.IsAbstract);
foreach (var pluginType in pluginTypes)
{
if (Activator.CreateInstance(pluginType) is IPluginDllApi pluginInstance)
{
if (pluginInstance != null)
_labPlugins.Add((pluginInstance));
}
}
}
catch (Exception ex)
{
Console.WriteLine($"Failed to load assembly {dllPath}: {ex.Message}");
}
}
}
}
}
3，然后我们在程序启动的时候进行调用
4，接下来我们创建一个PluginController.cs控制器，这个控制器实现了动态的路由。代码如下：
using DynamicPluginApiDemo.Utils;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Newtonsoft.Json.Linq;
namespace DynamicPluginApiDemo.Controllers
{
[Route("api/[controller]/{DynamicParam}")]
[ApiController]
public class PluginController : ControllerBase
{
/// <summary>
/// 动态插件的名称
/// </summary>
private readonly string _dynamicParam = string.Empty;
public PluginController(IHttpContextAccessor httpContextAccessor)
{
var dynamicParamKey = httpContextAccessor?.HttpContext?.GetRouteValue("DynamicParam");
if (dynamicParamKey != null)
_dynamicParam = dynamicParamKey?.ToString() ?? string.Empty;
}
// GET: api/ApifulPlugin/apidll/GetRequest/Query?SearchName=AAA
[HttpGet("GetRequest/{functionName}")]
public IActionResult GetRequest(string functionName, [FromQuery] Dictionary<string, string> queryParameters)
{
var instance = PluginDllHelper._labPlugins.FirstOrDefault(x => x.Name == _dynamicParam);
if (instance == null)
return NotFound();
return instance.GetRequest(functionName, queryParameters);
}
// POST: api/Dynamic/json
// Receives query parameters and JSON body
[HttpPost("PostRequestBody/{functionName}")]
public IActionResult PostRequestBody(string functionName, [FromQuery] Dictionary<string, string> queryParameters, [FromBody] object jsonData)
{
var instance = PluginDllHelper._labPlugins.FirstOrDefault(x => x.Name == _dynamicParam);
if (instance == null)
return NotFound();
return instance.PostRequestBody(functionName, queryParameters, jsonData);
}
// POST: api/Dynamic/form
[HttpPost("PostRequestForm/{functionName}")]
public IActionResult PostRequestForm(string functionName, [FromQuery] Dictionary<string, string> queryParameters, IFormCollection formData)
{
var instance = PluginDllHelper._labPlugins.FirstOrDefault(x => x.Name == _dynamicParam);
if (instance == null)
return NotFound();
return instance.PostRequestForm(functionName, queryParameters, formData);
}
}
}
5，webapi项目的内容差不多了。接下来我们创建一个类库项目，名字叫做BlogPluginApi。然后项目引用一下主项目，并且创建一个BlogPluginApi.cs文件继承主项目的IPluginDllApi。
using BlogPluginApi.Service;
using DynamicPluginApiDemo.Utils;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.SqlServer.Server;
namespace BlogPluginApi
{
public class BlogPluginApi : IPluginDllApi
{
public string Name => "BlogPluginApi";
public IActionResult GetRequest(string funName, Dictionary<string, string> queryParameters)
{
var result = string.Empty;
switch (funName)
{
case "Query":
result = BlogService.Query(queryParameters);
break;
}
return new ContentResult
{
StatusCode = 200,
ContentType = "text/plain",
Content = result
};
}
public IActionResult PostRequestBody(string funName, Dictionary<string, string> queryParameters, object jsonData)
{
var result = string.Empty;
switch (funName)
{
case "Save":
result = BlogService.Save(jsonData);
break;
case "Update":
result = BlogService.Update(jsonData);
break;
case "Delete":
result = BlogService.Delete(jsonData);
break;
}
return new ContentResult
{
StatusCode = 200,
ContentType = "text/plain",
Content = result
};
}
public IActionResult PostRequestForm(string funName, Dictionary<string, string> queryParameters, IFormCollection formData)
{
var result = string.Empty;
switch (funName)
{
case "UploadFile":
result = BlogService.UploadFile(queryParameters, formData);
break;
}
return new ContentResult
{
StatusCode = 200,
ContentType = "text/plain",
Content = result
};
}
}
}
6，然后我们增加blog表的实体，服务，模型等。当然这些可以放在主项目中，通过项目引用使用主项目的代码。
using SqlSugar;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace BlogPluginApi.Entitys.Blogs
{
[SugarTable("BLOG", TableDescription = "博客")]
public class Blog
{
[SugarColumn(ColumnName = "ID", IsIdentity = true, IsPrimaryKey = true)]
public int Id { get; set; }
[SugarColumn(ColumnName = "Title")]
public string Title { get; set; }
[SugarColumn(ColumnName = "Context")]
public string Context { get; set; }
[SugarColumn(ColumnName = "UserId")]
public int UserId { get; set; }
[SugarColumn(ColumnName = "CreateTime")]
public DateTime CreateTime { get; set; }
}
}
using SqlSugar;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace BlogPluginApi.Models.Blogs
{
public class BlogInputDto
{
public int? Id { get; set; }
public string? Title { get; set; }
public string? Context { get; set; }
public int? UserId { get; set; }
public DateTime? CreateTime { get; set; }
}
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace BlogPluginApi.Models.Blogs
{
public class SearchDto
{
public string SearchName { get; set; }
}
}
using AutoMapper;
using BlogPluginApi.Entitys.Blogs;
using BlogPluginApi.Models.Blogs;
using DynamicPluginApiDemo.Utils;
using Microsoft.AspNetCore.Http;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace BlogPluginApi.Service
{
public static class BlogService
{
public static string Query(Dictionary<string, string> queryParameters)
{
SearchDto searchBlogDto = new SearchDto();
if (queryParameters.TryGetValue("SearchName", out var searchName))
{
searchBlogDto.SearchName = searchName;
}
var result = string.Join(",", DbHelper.Db.Queryable<Blog>().Select(s => s.Title).ToList());
return result;
}
public static string Delete(object param)
{
var strParam = param.ToString();
if (string.IsNullOrEmpty(strParam)) return string.Empty;
var deleteIds = JsonConvert.DeserializeObject<List<int>>(strParam);
if (deleteIds != null)
{
var count = DbHelper.Db.Deleteable<Blog>().Where(x => deleteIds.Contains(x.Id)).ExecuteCommand();
return count.ToString();
}
return string.Empty;
}
public static string Save(object param)
{
var strParam = param.ToString();
if (string.IsNullOrEmpty(strParam)) return string.Empty;
var inputDto = JsonConvert.DeserializeObject<Blog>(strParam);
if (inputDto != null)
{
var count = DbHelper.Db.Insertable(inputDto).ExecuteCommand();
}
return "success";
}
public static string Update(object param)
{
var strParam = param.ToString();
if (string.IsNullOrEmpty(strParam)) return string.Empty;
var inputDto = JsonConvert.DeserializeObject<Blog>(strParam);
if (inputDto != null)
{
var count = DbHelper.Db.Updateable(inputDto).ExecuteCommand();
}
return "success";
}
public static string UploadFile(Dictionary<string, string> queryParameters, IFormCollection formData)
{
string UploadId = string.Empty;
if (queryParameters.TryGetValue("uploadId", out var uploadId))
{
UploadId = uploadId;
}
var file = formData.Files.FirstOrDefault();
if (file != null)
return file.FileName;
return string.Empty;
}
}
}
7，然后我们生成一下BlogPluginApi项目，把生成的dll文件放在放在主项目的Plugins文件夹下就可以了。
注意：
系统必须被设计为能够识别和管理不同的插件版本，并且能够在运行时安全地切换这些版本。
结语
Web API插件的热插拔是一个复杂但非常有价值的功能，它不仅提高了系统的灵活性和可用性，还增强了用户体验。通过精心规划和技术实践，可以使这一特性成为现代Web应用和服务的一个亮点。
标签：WebAPI,插件,string,C#,System,var,using,public From： https://www.cnblogs.com/BFMC/p/18687474