创建自己的规则

如果您需要创建自己的独特规则（针对任何标准未提供的事件），您必须创建派生的 MarketRule<TToken,TArg> 类，该类将与前提条件一起工作。下面是 MarketRuleHelper.WhenMoneyMore(StockSharp.BusinessEntities.Portfolio portfolio, StockSharp.BusinessEntities.IPortfolioProvider provider, StockSharp.Messages.Unit money ) 方法的实现：

private sealed class PortfolioRule : MarketRule<Portfolio, Portfolio>
{
	private readonly Func<Portfolio, bool> _changed;
	private readonly Portfolio _portfolio;
	private readonly IConnector _connector;
	public PortfolioRule(Portfolio portfolio, IConnector connector, Func<Portfolio, bool> changed) : base(portfolio)
	{
		if (portfolio == null)
			throw new ArgumentNullException("portfolio");
		if (changed == null)
			throw new ArgumentNullException("changed");
		_changed = changed;
		_portfolio = portfolio;
		_connector = connector;
		_connector.PortfolioChanged += OnPortfolioChanged;
	}
	private void OnPortfolioChanged(Portfolio portfolio)
	{
		if ((portfolio==_portfolio) && _changed(_portfolio))
			Activate(_portfolio);
	}
	protected override void DisposeManaged()
	{
		_connector.PortfolioChanged -= OnPortfolioChanged;
		base.DisposeManaged();
	}
}
		
public static MarketRule<Portfolio, Portfolio> WhenMoneyMore(this Portfolio portfolio, Unit money)
{
	if (portfolio == null)
		throw new ArgumentNullException("portfolio");
	if (money == null)
		throw new ArgumentNullException("money");
	var finishMoney = money.Type == UnitTypes.Limit ? money : portfolio.CurrentValue + money;
	return new PortfolioRule(portfolio, pf => pf.CurrentValue > finishMoney)
	{
		Name = "Money increase of portfolio {0} above {1}".Put(portfolio, finishMoney)
	};
}		

PortfolioRule 规则订阅了 IPortfolioProvider.PortfolioChanged 事件，一旦事件被触发，就会检查投资组合中的当前资金水平是否超过指定的限额。如果条件返回 true，则通过 MarketRule<TToken,TArg>.Activate 方法激活该规则。