/// <summary>
/// 访问表达式树后自动删掉访问的成员痕迹
/// </summary>
/// <param name="visit">访问委托</param>
protected void VisitWithoutRemark(Action <object> visit)
{
int visitedQty = _visitedStack.Count;
visit(null);
if (_visitedStack.Count != visitedQty)
{
_visitedStack.Remove(_visitedStack.Count - visitedQty);
}
}
/// <summary>
/// 将调度到此类中更专用的访问方法之一的表达式。
/// </summary>
/// <param name="node">方法节点</param>
/// <param name="router">方法路由</param>
/// <returns></returns>
public Expression Visit(Expression node, MethodCallType router)
{
int visitedQty = _visitedStack.Count;
Expression newNode = null;
if (router == MethodCallType.Coalesce)
{
newNode = this.VisitCoalesce((BinaryExpression)node);
}
else if (router == MethodCallType.EqualNull)
{
newNode = this.VisitEqualNull((BinaryExpression)node);
}
else if (router == MethodCallType.MethodCall)
{
newNode = this.VisitMethodCall((MethodCallExpression)node);
}
else if (router == MethodCallType.BinaryCall)
{
newNode = this.VisitMethodCall((BinaryExpression)node);
}
else if (router == MethodCallType.MemberMember)
{
newNode = this.VisitMemberMember((MemberExpression)node);
}
else if (router == MethodCallType.Unary)
{
newNode = this.VisitUnary((UnaryExpression)node);
}
// 自身已构成布尔表达式的则需要删除它本身所产生的访问链
if (_visitedStack.Count != visitedQty)
{
bool b = router != MethodCallType.Unary;
if (b && router == MethodCallType.MethodCall)
{
var m = (MethodCallExpression)node;
b = _removeVisitedMethods.Contains(m.Method.Name);
}
if (b)
{
_visitedStack.Remove(_visitedStack.Count - visitedQty);
}
}
return(newNode);
}