/// <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); } } }