ASP.NET Boilerplate 工作单元

从上往下说起，框架使用castle拦截器，拦截实现了IApplication、IRepository接口的所有方法，和使用了UnitOfWork 特性的方法，代码如下

internal class UnitOfWorkInterceptor : IInterceptor
{
private readonly IUnitOfWorkManager _unitOfWorkManager;

public UnitOfWorkInterceptor(IUnitOfWorkManager unitOfWorkManager)
{
_unitOfWorkManager = unitOfWorkManager;
}

public void Intercept(IInvocation invocation)
{
if (_unitOfWorkManager.Current != null)
{
//Continue with current uow
invocation.Proceed();
return;
}

var unitOfWorkAttr = UnitOfWorkAttribute.GetUnitOfWorkAttributeOrNull(invocation.MethodInvocationTarget);
if (unitOfWorkAttr == null || unitOfWorkAttr.IsDisabled)
{
//No need to a uow
invocation.Proceed();
return;
}

//No current uow, run a new one
PerformUow(invocation, unitOfWorkAttr.CreateOptions());
}
....

我们会看到如果当前工作单元为null的情况下会执行 PerformUow，那让我们看看它又做了哪些工作呢,看代码

private void PerformSyncUow(IInvocation invocation, UnitOfWorkOptions options)
{
using (var uow = _unitOfWorkManager.Begin(options))
{
invocation.Proceed();
uow.Complete();
}
}

拦截器注入了UnitOfWorkManager，那就看它，UnitOfWorkManager有一个Current属性和三个重载的Begin方法，UnitOfWorkManager调用Begin方法，方法通过IOC解析得到一个uow实例，然后做了两个工作，一是给当前Current赋值，二是调用uow的begin方法，代码如下

public IUnitOfWorkCompleteHandle Begin(UnitOfWorkOptions options)
{
options.FillDefaultsForNonProvidedOptions(_defaultOptions);

if (options.Scope == TransactionScopeOption.Required && _currentUnitOfWorkProvider.Current != null)
{
return new InnerUnitOfWorkCompleteHandle();
}

var uow = _iocResolver.Resolve<IUnitOfWork>();

...

uow.Begin(options);

_currentUnitOfWorkProvider.Current = uow;

return uow;
}

那就让我看看uow的begin方法究竟做了哪些工作，在UnitOfWorkBase类里面看，UnitOfWorkBase实现了IUnitOfWork接口，主要关心的就是Begin、Complete、SaveChanges三个方法的实现，那就让我们看看UnitOfWorkBase代码

public abstract class UnitOfWorkBase : IUnitOfWork
{
public string Id { get; private set; }

public IUnitOfWork Outer { get; set; }

public UnitOfWorkOptions Options { get; private set; }

...

protected UnitOfWorkBase(IUnitOfWorkDefaultOptions defaultOptions)
{
Id = Guid.NewGuid().ToString("N");
_filters = defaultOptions.Filters.ToList();
AbpSession = NullAbpSession.Instance;
}

/// <inheritdoc/>
public void Begin(UnitOfWorkOptions options)
{
if (options == null)
{
throw new ArgumentNullException("options");
}

PreventMultipleBegin();
Options = options; //TODO: Do not set options like that!

SetFilters(options.FilterOverrides);
//实现在EfUnitOfWork里
BeginUow();
}

/// <inheritdoc/>
public abstract void SaveChanges();

public void Complete()
{
PreventMultipleComplete();
try
{
CompleteUow();
_succeed = true;
OnCompleted();
}
catch (Exception ex)
{
_exception = ex;
throw;
}
}

protected abstract void BeginUow();

protected abstract void CompleteUow();

...

我们看到Begin、Complete方法分别调用了BeginUow、CompleteUow方法，真正干活的就是这个方法了，这两个方法的实现在具体的UnitOfWork类里，如EfUnitOfWork，到此工作单元工作的大体流程就讲完了，其中还有很多细节需要仔细的研究源码才能了解,

待编辑...