在ASP.NET Core中使用带有DbContext的异步中介器可以通过以下步骤实现:
public class AsyncMediator : IMediator
{
private readonly IMediator _mediator;
private readonly DbContext _dbContext;
public AsyncMediator(IMediator mediator, DbContext dbContext)
{
_mediator = mediator;
_dbContext = dbContext;
}
public async Task Send(IRequest request, CancellationToken cancellationToken = default)
{
// 在请求处理之前执行一些操作,比如开启事务
using (var transaction = await _dbContext.Database.BeginTransactionAsync(cancellationToken))
{
try
{
var response = await _mediator.Send(request, cancellationToken);
// 在请求处理之后执行一些操作,比如提交事务
await _dbContext.SaveChangesAsync(cancellationToken);
await transaction.CommitAsync(cancellationToken);
return response;
}
catch (Exception)
{
// 发生异常时回滚事务
await transaction.RollbackAsync(cancellationToken);
throw;
}
}
}
}
public void ConfigureServices(IServiceCollection services)
{
// 注册DbContext
services.AddDbContext(options =>
options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));
// 注册中介器和自定义的中介器类
services.AddMediatR(Assembly.GetExecutingAssembly());
services.AddTransient();
// 其他服务注册...
}
public class MyController : ControllerBase
{
private readonly IMediator _mediator;
public MyController(IMediator mediator)
{
_mediator = mediator;
}
[HttpPost]
public async Task Create(CreateModel model)
{
// 发送请求并处理响应
var response = await _mediator.Send(new CreateCommand(model));
return Ok(response);
}
}
以上代码演示了如何在ASP.NET Core中使用带有DbContext的异步中介器。在中介器中,可以执行一些通用的操作,比如开启事务、提交事务和回滚事务,以确保数据的一致性和完整性。