我有一个更高阶的函数来处理交易:
public static void ExecuteTransaction<Context, FunctionParameter>(Action<FunctionParameter> functionToBeExecuted,
FunctionParameter parameter,
Context context)
where Context : DbContext
{
using (var transaction = context.Database.BeginTransaction())
{
try
{
functionToBeExecuted(parameter);
context.SaveChanges();
transaction.Commit();
}
catch (Exception)
{
transaction.Rollback();
throw;
}
}
}
如何更改 ExecuteTransaction 方法以接受此方法及其参数?
public void DeleteBy(Expression<Func<TEntity, bool>> predicate)
{
var results = DbSet.Where(predicate).ToList();
DbSet.RemoveRange(results);
}
如果我理解正确,您正在尝试将DeleteBy
传递给ExecuteTransaction
,并ExecuteTransaction
运行该方法。
假设您有一个Expression<Func<TEntity, bool>>
来充当已经准备好DeleteBy
参数:
Expression<Func<TEntity, bool>> param = entity => /*some lambda that returns a bool */;
您可以直接传递DeleteBy
,而无需对ExecuteTransaction
进行任何更改,因为DeleteBy
匹配Action<T>
的签名:
ExecuteTransaction(DeleteBy, param, context);
编译器将自动推断FunctionParameter
Expression<Func<TEntity, bool>>
。