Question

我尝试在wpf的树视图中显示分层数据。 db表是一个自我引用员工表。

当我绑定到Xaml中的Observable集合时，没有任何东西出现。

以下是示例视图模型

public class EmployeeViewModel : ViewModel
    {
        public class EmployeeList
        {
            public Employee Employees { get; set; }
            public IEnumerable<EmployeeList> EmployeeChildren { get; set; }
        }


        private readonly ObservableCollection<EmployeeList> _EmployeeLists = new ObservableCollection<EmployeeList>();        


        //property
        public ObservableCollection<EmployeeList> EmployeeHierarchy
        {
            get
            {
                return _EmployeeLists;                                 
            }
        }

            //This is inside a method to make the db call
            try
            {   //Grab Employees from db using Wcf and EF
                WcfProxy.Using(delegate(IMyService client)
                {
                    _EmployeeLists.Clear();
                    var query = client.GetEmployees();
                    var results = GetEmployeesHierachy(query.AsEnumerable(), null).ToList();                   
                });
            }
            catch (Exception e)
            {

                throw e;
            }
        }

        //Method to build hierarchy
        public IEnumerable<EmployeeList> GetEmployeesHierachy(IEnumerable<Employee> allEmployees, Employee parentEmployee)
        {
            int? parentEmployeeId = null;

            if (parentEmployee != null)
                parentEmployeeId = parentEmployee.EmployeeId;

            var childEmployees = allEmployees.Where(e => e.EmployeeParentId == parentEmployeeId);

            foreach (var emp in childEmployees)
                _EmployeeLists.Add(new EmployeeList() { Employees = emp, EmployeeChildren = GetEmployeesHierachy(allEmployees, emp) });

            return _EmployeeLists;
        }

    }

这是xaml

<Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="*" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="325" />
            <ColumnDefinition Width="Auto" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>
        <TreeView Name="ItemTreeView"
                  ItemsSource="{Binding Path=EmployeeHierarchy}">
            <TreeView.ItemTemplate>
                <HierarchicalDataTemplate ItemsSource="{Binding Path=Employees}">
                    <HierarchicalDataTemplate.ItemTemplate>
                        <DataTemplate>
                            <Grid>
                                <Grid.ColumnDefinitions>
                                    <ColumnDefinition />
                                    <ColumnDefinition />
                                </Grid.ColumnDefinitions>
                                <TextBlock Grid.Column="0" FontFamily="Segoe UI" FontSize="14"
                                           Text="{Binding Path=Name1, StringFormat='Employee Full Name {0}'}" Padding="2"
                                           Width="200" />
                                <TextBlock Grid.Column="1" FontFamily="Segoe UI" FontSize="14" Padding="2" />
                            </Grid>
                        </DataTemplate>
                    </HierarchicalDataTemplate.ItemTemplate>
                </HierarchicalDataTemplate>
            </TreeView.ItemTemplate>
        </TreeView>
    </Grid>

EF将Name1作为字符串从Employee实体返回，这是我的textblock所绑定的。

我使用的Employee实体中的3个属性是EmployeeId，EmployeeParentId和Name

我错过了xaml中的内容吗？

Treeview在绑定到Observable Collection时不显示项目

0 个答案: