/// <summary>
/// 访问成员初始化表达式，如 => new App { Name = "Name" }
/// </summary>
/// <param name="node">要访问的成员初始化表达式</param>
/// <returns></returns>
protected override Expression VisitMemberInit(MemberInitExpression node)
{
if (_navDescriptorKeys == null)
{
_navDescriptorKeys = new List <string>();
}
if (_navDescriptorKeys.Count == 0)
{
_navDescriptorKeys.Add(node.Type.Name);
}
// New 表达式
if (node.NewExpression != null)
{
this.VisitNewImpl(node.NewExpression, false);
}
// 赋值表达式
var newBindings = node.Bindings.OrderBy(a => TypeUtils.IsPrimitive(a.Member) ? 0 : 1);
newBindings.ForEach(m => this.VisitWithoutRemark(_ => this.VisitMemberAssignmentImpl(node.Type, (MemberAssignment)m)));
return(node);
}
// => Name = "Name"
private void VisitMemberAssignmentImpl(Type newType, MemberAssignment m)
{
// 先添加当前字段的访问痕迹标记
_visitedStack.Add(m.Member, newType);
if (TypeUtils.IsPrimitive(m.Member))
{
this.VisitMemberBinding(m);
// 选择字段
this.AddSelectedColumn(m.Member, newType);
}
else
{
// 非显式指定的导航属性需要有 ForeignKeyAttribute
if (m.Expression.NodeType == ExpressionType.MemberAccess && m.Expression.Visitable())
{
var typeRuntime = TypeRuntimeInfoCache.GetRuntimeInfo(newType);
var attribute = typeRuntime.GetMemberAttribute <ForeignKeyAttribute>(m.Member.Name);
// 不能当做导航属性的复杂字段
if (attribute == null)
{
return;
}
}
// 生成导航属性描述集合，以类名.属性名做为键值
if (_navDescriptorKeys == null)
{
_navDescriptorKeys = new List <string>();
}
if (_navDescriptors == null)
{
_navDescriptors = new NavDescriptorCollection();
}
int num = _navDescriptorKeys.Count;
string keyId = _navDescriptorKeys.Count > 0 ? _navDescriptorKeys[_navDescriptorKeys.Count - 1] : string.Empty;
keyId = !string.IsNullOrEmpty(keyId) ? keyId + "." + m.Member.Name : m.Member.Name;
var nav = new NavDescriptor(keyId, m.Member);
if (!_navDescriptors.Contains(keyId))
{
// Fix issue# spliton 列占一个位
nav.StartIndex = _selectedColumns.Count;
nav.FieldCount = GetFieldCount(m.Expression) + (m.Expression.NodeType == ExpressionType.MemberAccess && m.Expression.Visitable() ? 1 : 0);
_navDescriptors.Add(nav);
_navDescriptorKeys.Add(keyId);
}
// 1.不显式指定导航属性，例：a.Client.ClientList
// 2.表达式里显式指定导航属性，例：b
if (m.Expression.NodeType == ExpressionType.MemberAccess)
{
this.VisitNavigation(m.Expression as MemberExpression, m.Expression.Visitable());
}
else if (m.Expression.NodeType == ExpressionType.New)
{
this.VisitNewImpl(m.Expression as NewExpression, false);
}
else if (m.Expression.NodeType == ExpressionType.MemberInit)
{
this.VisitMemberInit(m.Expression as MemberInitExpression);
}
// 恢复访问链
// 在访问导航属性时可能是 Client.CloudServer，这时要恢复为 Client，以保证能访问 Client 的下一个导航属性
if (_navDescriptorKeys.Count != num)
{
_navDescriptorKeys.RemoveAt(_navDescriptorKeys.Count - 1);
}
}
}
