105 lines
3.7 KiB
C#
105 lines
3.7 KiB
C#
using CloudBuilder.Core.Service;
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using Microsoft.AspNetCore.Mvc;
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using Microsoft.AspNetCore.Mvc.Filters;
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using Microsoft.EntityFrameworkCore;
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using System;
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using System.Collections.Generic;
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using System.Linq;
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using System.Text;
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using System.Threading.Tasks;
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using System.Transactions;
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namespace CloudBuilder.Core.DatabaseAccessor
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{
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/*
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事务范围：TransactionScopeOption.RequiresNew 管理的是分布式事务，
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TransactionScopeOption.Required但对于单个数据库连接，通常不需要分布式事务。
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OnActionExecutionAsync 是 ASP.NET Core 中异步的 Action 过滤器执行方法。
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// OnActionExecuting: Action 执行前
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[开始事务]
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↓
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[Action 方法执行]
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↓
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// OnActionExecuted: Action 执行后（无论是否异常）
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[检查异常]
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//Controller对象不抛出异常，返回的是异常对象ValidatedException、ServiceErrorException（方便前端信息统一处理）
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[提交或回滚事务]
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*/
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[AttributeUsage(AttributeTargets.Method)]
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public class UnitOfWorkAttribute : ActionFilterAttribute
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{
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private TransactionScope _transactionScope;
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public override void OnActionExecuting(ActionExecutingContext context)
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{
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_transactionScope = new TransactionScope(TransactionScopeOption.RequiresNew,
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new TransactionOptions
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{
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IsolationLevel = IsolationLevel.ReadCommitted,
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Timeout = TransactionManager.MaximumTimeout
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});
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base.OnActionExecuting(context);
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}
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//public override void OnActionExecuting(ActionExecutingContext context)
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//{
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// // 正确：单机数据库事务（不是分布式）
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// _transactionScope = new TransactionScope(
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// TransactionScopeOption.Required,
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// new TransactionOptions
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// {
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// IsolationLevel = IsolationLevel.ReadCommitted
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// },
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// TransactionScopeAsyncFlowOption.Enabled); // 必须加这个
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// base.OnActionExecuting(context);
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//}
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public override void OnActionExecuted(ActionExecutedContext context)
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{
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if (_transactionScope == null)
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{
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base.OnActionExecuted(context);
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return;
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}
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bool needRollback = false;
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try
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{
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// ==============================================
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// 核心逻辑：判断返回值是不是异常对象
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// ==============================================
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if (context.Result is ObjectResult objectResult)
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{
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var value = objectResult.Value;
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if (value != null)
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{
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// 只要是这两个异常 → 必须回滚
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if (value is ValidatedException || value is ServiceErrorException)
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{
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needRollback = true;
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}
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}
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}
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// 如果没有异常，才提交
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if (!needRollback)
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{
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//必须要有 SaveChanges() 调用，否则数据只会停留在内存中，不会真正保存到数据库。
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_transactionScope.Complete();
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}
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}
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finally
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{
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// 不 Complete() 就是自动回滚
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_transactionScope.Dispose();
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}
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base.OnActionExecuted(context);
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}
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}
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}
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