wpf databound RadGrid - 为什么网格未检测到视图模型的更改？

Question

我正在尝试生成一个与 Visual Studio 中的错误列表非常相似的错误列表。

我有一个视图和视图模型。我更新单例视图模型并通知属性发生更改，这是实际消息（错误和警告）。然而，网格保持不变——出了什么问题？！

我已经逐步完成，集合 _messages 已正确更新，并且初始消息已正确显示，但在视图模型更新后仍保留在视图中。换句话说，这应该是根据正确的视图模型进行视图更新的问题。

我知道 RadPane 中的错误会导致窗格失去与视图模型的连接，并已实施标准解决方法。

视图模型实现 INotifyPropertyChanged。

（在 xaml 中添加了 NotifySourceUpdated 试图补救，但无济于事）

（由于 Stackoverflow 限制，视图中的括号被替换）

感谢您的任何输入和见解...

Anders，丹麦

视图：

    [Controls:RadPane x:Class="Rap1D.Rap1D_WPF.Views.ErrorListView"
                 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                 xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
                 xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:Controls="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls.Docking" xmlns:telerik="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls.GridView" mc:Ignorable="d" 
                 d:DesignHeight="74" d:DesignWidth="298" Header="{Binding Header}" DataContextChanged="RadPane_DataContextChanged"]
        [Grid]
            [telerik:RadGridView AutoGenerateColumns="False" x:Name="grid" ItemsSource="{Binding Path=Messages, NotifyOnSourceUpdated=True}" Margin="0,0,0,37"]
                [telerik:RadGridView.Columns]
                    [telerik:GridViewDataColumn Header="Message" DataMemberBinding="{Binding Path=Message, NotifyOnSourceUpdated=True}" /]
                [/telerik:RadGridView.Columns]
            [/telerik:RadGridView]
        [/Grid]
    [/Controls:RadPane]

ViewModel：

    using System;
    using System.Collections.Generic;
    using System.Linq;
    using Rap1D.ViewModelLayer.Interfaces;
    using Rap1D.ViewModelLayer.Interfaces.TreeViewItems;

    namespace Rap1D.ViewModelLayer.Implementations
    {
        public class ErrorListViewModel :ViewModelBase, IErrorListViewModel
        {
            private readonly List<INotificationMessage> _messages;

            public ErrorListViewModel()
            {
                _messages = new List<INotificationMessage>();
            }

            public string Header
            {
                get { return "Error List"; }
            }

            public IEnumerable<INotificationMessage> Messages
            {
                get { return _messages; }
            }

            public void RemoveNotificationsForItem(IProductComponentViewModel productComponentViewModel)
            {
                var toDelete = (from m in _messages 
                                where m.Item == productComponentViewModel 
                                select m).ToList();
                foreach (var notificationMessage in toDelete)
                {
                    _messages.Remove(notificationMessage);
                }
                OnPropertyChanged("Messages");
            }

            public void AddNotifications(IProductComponentViewModel productComponentViewModel, IEnumerable<INotificationMessage> list)
            {
                _messages.AddRange(list);
                OnPropertyChanged("Messages");
            }
        }
    }

ErrorManager：

    using System.Collections.Generic;
    using Rap1D.ViewModelLayer.Interfaces;
    using Rap1D.ViewModelLayer.Interfaces.Managers;
    using Rap1D.ViewModelLayer.Interfaces.Providers;
    using Rap1D.ViewModelLayer.Interfaces.TreeViewItems;

    namespace Rap1D.ViewModelLayer.Implementations.Managers
    {
        public class ErrorManager : IErrorManager
        {
            private readonly IErrorListViewModelProvider _errorListViewModelProvider;

            public ErrorManager(IErrorListViewModelProvider errorListViewModelProvider)
            {
                _errorListViewModelProvider = errorListViewModelProvider;
            }

            public void UpdateNotificationsForItem(IProductComponentViewModel productComponentViewModel,
                                                   IEnumerable<INotificationMessage> list)
            {
                var errorListViewModel = _errorListViewModelProvider.GetViewModel();

                errorListViewModel.RemoveNotificationsForItem(productComponentViewModel);
                errorListViewModel.AddNotifications(productComponentViewModel, list);
            }
        }
    }

Answer 1

所要做的就是将 List 更改为 ObservableCollection。

有人可以解释为什么我最初的解决方案没有按预期工作吗？

    using System.Collections.Generic;
    using System.Collections.ObjectModel;
    using System.Linq;
    using Microsoft.Practices.Prism;
    using Rap1D.ViewModelLayer.Interfaces;
    using Rap1D.ViewModelLayer.Interfaces.TreeViewItems;

    namespace Rap1D.ViewModelLayer.Implementations
    {
        public class ErrorListViewModel : ViewModelBase, IErrorListViewModel
        {
            private readonly ObservableCollection<INotificationMessage> _messages;

            public ErrorListViewModel()
            {
                _messages = new ObservableCollection<INotificationMessage>();
            }

            public string Header
            {
                get { return "Error List"; }
            }

            public void AddNotifications(IProductComponentViewModel productComponentViewModel,
                                         IEnumerable<INotificationMessage> list)
            {
                _messages.AddRange(list);
                OnPropertyChanged("Messages");
            }

            public IEnumerable<INotificationMessage> Messages
            {
                get { return _messages; }
            }

            public void RemoveNotificationsForItem(IProductComponentViewModel productComponentViewModel)
            {
                var toDelete = (from m in _messages
                                //where m.Item == productComponentViewModel 
                                select m).ToList();
                foreach (var notificationMessage in toDelete)
                {
                    _messages.Remove(notificationMessage);
                }
                OnPropertyChanged("Messages");
            }
        }
    }

Answer 2

ObservableCollections 支持 PropertyChangeNotification；其他集合需要 RaisePropertyChanged("ObjectName")。