如何更新ObservableCollection条目并更新视图？

Question

我正在使用EntityFramework 6和MVVMLight，但遇到一个我不确定如何以最佳方式解决的问题。

我有一个EquipmentOverview，其中显示了一个设备列表，我们可以通过使用Add New，Edit和Delete按钮进行管理。现在，添加新项或删除它们很顺利，因为我可以使用.Add()中的.Remove()和ObservableCollection<EquipmentViewModel>，并且由于RaisePropertyChanged();中的RaisePropertyChanged();，它会自动更新UI列表。 SelectedEquipment对象。

我的问题在于更新设备。我有这个Save方法，它可以很好地更新数据库条目，但是由于某种原因，我无法获得UI列表来更新修改后的Equipment。最好的方法是什么？

EquipmentManagementViewModel.cs

在TODO：点，我想同时更新ObservableCollection列表和UI。我认为UI应该已经更新，因为我在SelectedEquipment上有一个namespace Manager.ViewModel { public class EquipmentManagementViewModel : ViewModelBase { // Models private EquipmentOverviewViewModel _equipmentOverviewViewModel; public EquipmentViewModel Equipment { get; set; } public ObservableCollection<CategoryViewModel> Categories { get; set; } // Commands public ICommand CancelCommand { get; set; } public ICommand SaveCommand { get; set; } public EquipmentManagementViewModel(EquipmentOverviewViewModel e) { _equipmentOverviewViewModel = e; Equipment = _equipmentOverviewViewModel.SelectedEquipment ?? new EquipmentViewModel(); RequestCategories(); InitializeCommands(); } private void RequestCategories() { CategoryRepository c = new CategoryRepository(); var categoryList = c.GetCategories(); Categories = new ObservableCollection<CategoryViewModel>(categoryList); } private void InitializeCommands() { SaveCommand = new RelayCommand(Save); CancelCommand = new RelayCommand(Cancel); } private void Save() { using (var context = new ManagerEntities()) { if (context.Equipments.Find(Equipment.ToModel().Id) != null) { Equipment e = context.Equipments.Find(Equipment.ToModel().Id); EquipmentViewModel equipmentViewModel = new EquipmentViewModel(e); equipmentViewModel.SetEquipment(Equipment.ToModel()); // TODO: Update Equipment in _equipmentOverviewViewModel.Equipments _equipmentOverviewViewModel.SelectedEquipment = Equipment; } else { context.Equipments.Add(Equipment.ToModel()); _equipmentOverviewViewModel.Equipments.Add(Equipment); } context.SaveChanges(); } _equipmentOverviewViewModel.equipmentManagementWindow.Close(); } private void Cancel() { _equipmentOverviewViewModel.equipmentManagementWindow.Close(); } } } ，但是当我更改它时，UI中没有任何更新...

namespace Manager.ViewModel
{
    public class EquipmentOverviewViewModel : ViewModelBase
    {
        // Windows
        public EquipmentManagementWindow equipmentManagementWindow;

        // Models
        public ObservableCollection<EquipmentViewModel> Equipments { get; set; }
        private EquipmentViewModel _selectedEquipment;
        public EquipmentViewModel SelectedEquipment
        {
            get { return _selectedEquipment; }
            set { _selectedEquipment = value; RaisePropertyChanged(); }
        }

        // Commands
        public ICommand AddEquipmentCommand { get; set; }
        public ICommand EditEquipmentCommand { get; set; }
        public ICommand DeleteEquipmentCommand { get; set; }

        public EquipmentOverviewViewModel()
        {
            InitializeCommands();

            EquipmentRepository equipmentRepository = new EquipmentRepository();
            var equipmentList = equipmentRepository.GetEquipments();
            Equipments = new ObservableCollection<EquipmentViewModel>(equipmentList);
        }

        private void InitializeCommands()
        {
            AddEquipmentCommand = new RelayCommand(AddEquipment);
            EditEquipmentCommand = new RelayCommand(EditEquipment, HasSelected);
            DeleteEquipmentCommand = new RelayCommand(DeleteEquipment, HasSelected);
        }

        private void AddEquipment()
        {
            SelectedEquipment = null;
            EditEquipment();
        }

        private void EditEquipment()
        {
            equipmentManagementWindow = new EquipmentManagementWindow();
            equipmentManagementWindow.Show();
        }

        private void DeleteEquipment()
        {
            using (var context = new ManagerEntities())
            {
                Equipment equipment = SelectedEquipment.ToModel();
                context.Equipments.Attach(equipment);
                context.Equipments.Remove(equipment);
                context.SaveChanges();
            }
            Equipments.Remove(SelectedEquipment);
        }

        private bool HasSelected()
        {
            return SelectedEquipment != null;
        }
    }
}

EquipmentOverviewViewModel.cs

<Window x:Class="Manager.View.EquipmentOverviewWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:Manager.View"
        mc:Ignorable="d"
        WindowStartupLocation="CenterScreen"
        ResizeMode="NoResize"
        DataContext="{Binding EquipmentOverview, Source={StaticResource Locator}}"
        Title="Manage Equipment" Height="350" Width="550">
    <StackPanel>
        <Grid Margin="10,10,10,0" Height="250">
            <DataGrid AutoGenerateColumns="False" IsReadOnly="True"
                      SelectedItem="{Binding SelectedEquipment}" ItemsSource="{Binding Equipments}">
                <DataGrid.Columns>
                    <DataGridTextColumn Header="#" Binding="{Binding Id}" />
                    <DataGridTextColumn Header="Name" Binding="{Binding Name}" Width="160" />
                    <DataGridTextColumn Header="Intelligence" Binding="{Binding Intelligence}" Width="75" />
                    <DataGridTextColumn Header="Strength" Binding="{Binding Strength}" Width="60" />
                    <DataGridTextColumn Header="Agility" Binding="{Binding Agility}" Width="50" />
                    <DataGridTextColumn Header="Value" Binding="{Binding Value}" Width="50" />
                    <DataGridTextColumn Header="Category" Binding="{Binding CategoryName}" Width="*" />
                </DataGrid.Columns>
            </DataGrid>
        </Grid>
        <Grid Margin="0,0,0,10" Height="45" VerticalAlignment="Center" HorizontalAlignment="Center">
            <Grid.ColumnDefinitions>
                <ColumnDefinition Width="*" />
                <ColumnDefinition Width="*" />
                <ColumnDefinition Width="*" />
            </Grid.ColumnDefinitions>

            <Button Width="100" Height="30" FontSize="16"
                        Foreground="White" Background="#FF6F9BDA" Content="Add New"
                        Grid.Column="0" Command="{Binding AddEquipmentCommand}">
            </Button>
            <Button Width="100" Height="30" FontSize="16"
                        Foreground="White" Background="#FF6F9BDA" Content="Edit"
                        Grid.Column="1" Command="{Binding EditEquipmentCommand}">
            </Button>
            <Button Width="100" Height="30" FontSize="16"
                        Foreground="White" Background="#FF6F9BDA" Content="Delete"
                        Grid.Column="2" Command="{Binding DeleteEquipmentCommand}">
            </Button>
        </Grid>
    </StackPanel>
</Window>

，如有必要，还有EquipmentOverviewWindow.xaml

import java.util.Arrays;
public class MyClass {
    public static void main(String[] args) {

        String[] ArrayInput = new String[] { "The", "Black", "Cat" };

        outputInReverse(ArrayInput);

    }




    public static void outputInReverse(String[] FirstOrder) {
        String[] FinalOrder = new String[] {"One", "Two", "Three"};

        for (int i = 2; i >= 0; i--) {
            for (int j = 0; j <= 2; j++) {
                FinalOrder[j] = FirstOrder[i];
                System.out.println(FinalOrder[j]);

            }
        }
        System.out.println(Arrays.toString(FinalOrder));
    }

}

任何提示将不胜感激。看来我正在忽略某些东西。