当从另一个视图（RoomGrid）添加元素时，我的ReservationView不会刷新它的元素，但它实际上已添加到数据库中，是否存在是否有可能自动刷新它，同时在Rooms上将DbSet<Room> ObservableCollection<Room>声明为DatabaseContext而不是ObservableCollection<Room>？
如果有可能那么我该怎么做？
如果没有，那么如何在不重写源代码的情况下在我的解决方案上实现DatabaseContext.cs？ （源代码所需的更改是什么？）
（我正在使用MVVM设计模式，Linq，实体框架）
我using Fondok.Models;
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Data.Entity.ModelConfiguration.Conventions;
using System.Data.SQLite;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Fondok.Context
{
class DatabaseContext : DbContext
{
public DatabaseContext() :
base(new SQLiteConnection()
{
ConnectionString = new SQLiteConnectionStringBuilder()
{
DataSource = Environment.GetFolderPath(Environment.SpecialFolder.Desktop) + "\\fondok.db",
ForeignKeys = true
}.ConnectionString
}, true)
{
}
public DbSet<Client> Clients { get; set; }
public DbSet<Room> Rooms { get; set; }
public DbSet<Employee> Employees { get; set; }
public DbSet<Form> Forms { get; set; }
public DbSet<Reservation> Reservations { get; set; }
public DbSet<Invoice> Invoices { get; set; }
}
}
的源代码：
RoomViewModel.cs我using Fondok.Models;
using System.ComponentModel;
using System.Runtime.CompilerServices;
using Fondok.Views.Windows;
using Fondok.Context;
using System.Data.Entity;
using System.Linq;
using System.Windows.Input;
using Fondok.Commands;
using System;
using System.Windows;
using System.Collections.Generic;
using System.Windows.Data;
namespace Fondok.ViewModels
{
// ISIL 2016/2017 -------------------------------------------
// RoomViewModel Class
class RoomViewModel : INotifyPropertyChanged, IDataErrorInfo
{
//Constructor Null FirstTime
public RoomViewModel() : this(null) { }
// Constructor With Param Of The Model
public RoomViewModel(Room Room)
{
// Add Room To Edit
EditRoom = Room;
//Validate Property
IsValidProperty = false;
//Make Properties With Fields Values
RoomNumber = EditRoom.RoomNumber;
RoomFloor = EditRoom.RoomFloor;
RoomType = EditRoom.RoomType;
RoomCapacity = EditRoom.RoomCapacity;
RoomStatus = EditRoom.RoomStatus;
RoomPrice = EditRoom.RoomPrice;
}
//IsValidProperty For Validation
private bool _IsValidProperty;
public bool IsValidProperty
{
get
{
return _IsValidProperty;
}
set
{
if (_IsValidProperty != value)
{
_IsValidProperty = value;
NotifyPropertyChanged("IsValidProperty");
}
}
}
// Implementation Of IDataErrorInfo For Validation
public string Error
{
get
{
return string.Empty;
}
}
// RoomNumber Property
private int _RoomNumber;
public int RoomNumber
{
get
{
return _RoomNumber;
}
set
{
if (_RoomNumber != value)
{
_RoomNumber = value;
EditRoom.RoomNumber = _RoomNumber;
NotifyPropertyChanged("RoomNumber");
}
}
}
// RoomFloor Property
private int _RoomFloor;
public int RoomFloor
{
get
{
return _RoomFloor;
}
set
{
if (_RoomFloor != value)
{
_RoomFloor = value;
EditRoom.RoomFloor = _RoomFloor;
NotifyPropertyChanged("RoomFloor");
}
}
}
// RoomType Property
private string _RoomType;
public string RoomType
{
get
{
return _RoomType;
}
set
{
if (_RoomType != value)
{
_RoomType = value;
EditRoom.RoomType = _RoomType;
NotifyPropertyChanged("RoomType");
}
}
}
// RoomCapacity Property
private int _RoomCapacity;
public int RoomCapacity
{
get
{
return _RoomCapacity;
}
set
{
if (_RoomCapacity != value)
{
_RoomCapacity = value;
EditRoom.RoomCapacity = _RoomCapacity;
NotifyPropertyChanged("RoomCapacity");
}
}
}
// RoomStatus Property
private string _RoomStatus;
public string RoomStatus
{
get
{
return _RoomStatus;
}
set
{
if (_RoomStatus != value)
{
_RoomStatus = value;
EditRoom.RoomStatus = _RoomStatus;
NotifyPropertyChanged("RoomStatus");
}
}
}
// RoomPrice Property
private double _RoomPrice;
public double RoomPrice
{
get
{
return _RoomPrice;
}
set
{
if (_RoomPrice != value)
{
_RoomPrice = value;
EditRoom.RoomPrice = _RoomPrice;
NotifyPropertyChanged("RoomPrice");
}
}
}
// Add Conditions & Error Messages
public string this[string columnName]
{
get
{
string FillRequired = "Please Fill The Field";
switch (columnName)
{
case "RoomNumber":
if (RoomNumber <= 0 || RoomNumber > 9999) return FillRequired;
break;
case "RoomFloor":
if (RoomFloor <= 0 || RoomFloor > 99) return FillRequired;
break;
case "RoomCapacity":
if (RoomCapacity <= 0 || RoomCapacity > 11) return FillRequired;
break;
case "RoomPrice":
if (RoomPrice <= 0 || RoomPrice > 999999) return FillRequired;
break;
}
return string.Empty;
}
}
// Edit Room Property
private Room _editRoom;
public Room EditRoom
{
get
{
return _editRoom;
}
set
{
_editRoom = value;
NotifyPropertyChanged("EditRoom");
}
}
// RoomWindow Run() Method
public bool Run()
{
RoomWindow window = new RoomWindow();
window.DataContext = this;
if (window.ShowDialog() == true) { return true; }
return false;
}
// MVVM NotifyPropertyChanged Implementation
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
// ISIL 2016/2017 -------------------------------------------
// RoomDataInteraction Class Create, Read, Update, Delete
class RoomDataInteraction
{
// Loading Data From DB
DatabaseContext db = new DatabaseContext();
// RoomDataInteraction Constructor
public RoomDataInteraction(DatabaseContext _db)
{
db = _db;
db.Rooms.Load();
}
// Insert Data From To BindingList
public System.ComponentModel.BindingList<Room> GetAllRooms()
{
return db.Rooms.Local.ToBindingList();
}
// Adding Method
public void AddRoom(Room Room)
{
db.Rooms.Add(Room);
db.SaveChanges();
}
// Get Room Method
public Room GetRoom(int id)
{
return db.Rooms.Where(get => get.RoomID.Equals(id)).First();
}
// Update Room Method FirstTime
public void UpdateRoom(
int RoomID,
int RoomNumber,
int RoomFloor,
string RoomType,
int RoomCapacity,
string RoomStatus,
double RoomPrice
)
{
Room Room = GetRoom(RoomID);
Room.RoomNumber = RoomNumber;
Room.RoomFloor = RoomFloor;
Room.RoomType = RoomType;
Room.RoomCapacity = RoomCapacity;
Room.RoomStatus = RoomStatus;
Room.RoomPrice = RoomPrice;
db.SaveChanges();
}
// Update RoomStatus (getReserved) Amine Modification
public void UpdateRoomStatus(
int RoomNumber,
string RoomStatus )
{
Room Room = GetRoom(RoomNumber);
Room.RoomStatus = RoomStatus;
db.SaveChanges();
}
// Update Room Method After Insert
public void UpdateRoom(Room update)
{
UpdateRoom(
update.RoomID,
update.RoomNumber,
update.RoomFloor,
update.RoomType,
update.RoomCapacity,
update.RoomStatus,
update.RoomPrice
);
}
// Delete Room Method
public void DeleteRoom(int id)
{
db.Rooms.Remove(GetRoom(id));
db.SaveChanges();
}
}
// ISIL 2016/2017 -------------------------------------------
// RoomBox Class
class RoomBox : INotifyPropertyChanged
{
private RoomDataInteraction box;
private DatabaseContext db;
private BindingList<Room> _Rooms;
// Rooms BindingList Property
public BindingList<Room> Rooms
{
get
{
return _Rooms;
}
set
{
_Rooms = value;
NotifyPropertyChanged("Rooms");
}
}
// SelectedRoom Property
private Room _selectedRoom;
public Room SelectedRoom
{
get
{
return _selectedRoom;
}
set
{
_selectedRoom = value;
NotifyPropertyChanged("SelectedRoom");
}
}
// RoomBox Constructor
public RoomBox()
{
db = new DatabaseContext();
box = new RoomDataInteraction(db);
Rooms = box.GetAllRooms();
deleteCommand = new DelegateCommand(DeleteRoom);
updateCommand = new DelegateCommand(UpdateRoom);
createCommand = new DelegateCommand(CreateRoom);
}
// Check if Room Selected?
public bool IsSelected()
{
return SelectedRoom != null;
}
// Implementation Of DeleteCommand Property
private ICommand deleteCommand;
public ICommand DeleteCommand
{
get
{
return deleteCommand;
}
}
// Delete the Selected Room Method & Refresh Rooms Binding :)
public void DeleteRoom()
{
if (!IsSelected())
{
return;
}
box.DeleteRoom(SelectedRoom.RoomID);
Rooms.ResetBindings();
}
// Implementation Of UpdateCommand Property
private DelegateCommand updateCommand;
public ICommand UpdateCommand
{
get
{
return updateCommand;
}
}
// Update the Selected Room Method & Refresh Rooms Binding :)
public void UpdateRoom()
{
// Check If Selected?
if (!IsSelected())
{
return;
}
// Create View Model With Selected Room To Edit
RoomViewModel vm = new RoomViewModel(SelectedRoom);
// Run The Room Window And Add Selected Room To Edit & Refresh Binding
if (vm.Run())
{
box.UpdateRoom(SelectedRoom);
Rooms.ResetBindings();
}
}
// Implementation Of CreateCommand Property
private DelegateCommand createCommand;
public ICommand CreateCommand
{
get
{
return createCommand;
}
}
// Create Room Method & Refresh Rooms Binding :)
public void CreateRoom()
{
Room create = new Room();
RoomViewModel vm = new RoomViewModel(create);
// Run The Room Window To Create Room & Refresh Binding
if (vm.Run())
{
box.AddRoom(create);
Rooms.ResetBindings();
}
}
// MVVM NotifyPropertyChanged Implementation
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}
}
的源代码：
RoomView.xaml我<UserControl
x:Class="Fondok.Views.RoomView"
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:local="clr-namespace:Fondok.Views"
xmlns:materialDesign="http://materialdesigninxaml.net/winfx/xaml/themes"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:prism="http://prismlibrary.com/"
xmlns:vm="clr-namespace:Fondok.ViewModels"
prism:ViewModelLocator.AutoWireViewModel="True"
Background="{DynamicResource MaterialDesignPaper}"
FontFamily="{DynamicResource MaterialDesignFont}"
Loaded="RoomViewLoaded"
TextElement.FontSize="18"
TextElement.FontWeight="Regular"
TextElement.Foreground="{DynamicResource MaterialDesignBody}"
TextOptions.TextFormattingMode="Ideal"
TextOptions.TextRenderingMode="Auto"
mc:Ignorable="d">
<UserControl.DataContext>
<vm:RoomBox />
</UserControl.DataContext>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="*" />
<RowDefinition Height="64" />
</Grid.RowDefinitions>
<Grid Grid.Row="0">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="auto" />
<ColumnDefinition Width="auto" />
<ColumnDefinition Width="auto" />
</Grid.ColumnDefinitions>
</Grid>
<Grid Grid.Row="0">
<DataGrid
x:Name="RoomsGrid"
Grid.Row="0"
AutoGenerateColumns="True"
Background="{Binding MaterialDesignBackground}"
BorderBrush="{x:Null}"
CanUserAddRows="True"
CanUserResizeRows="False"
ColumnWidth="*"
FontSize="16"
IsReadOnly="True"
ItemsSource="{Binding Rooms, IsAsync=True, Mode=TwoWay}"
SelectedItem="{Binding SelectedRoom}"
SelectionMode="Single">
<DataGrid.CellStyle>
<Style TargetType="DataGridCell">
<Setter Property="BorderThickness" Value="0" />
<Setter Property="FocusVisualStyle" Value="{x:Null}" />
<Setter Property="Padding" Value="16" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type DataGridCell}">
<Border
Padding="{TemplateBinding Padding}"
Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
SnapsToDevicePixels="True">
<ContentPresenter SnapsToDevicePixels="{TemplateBinding SnapsToDevicePixels}" />
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="IsSelected" Value="True">
<Setter Property="Background" Value="{DynamicResource PrimaryHueLightBrush}" />
<Setter Property="Foreground" Value="White" />
</Trigger>
</Style.Triggers>
</Style>
</DataGrid.CellStyle>
</DataGrid>
</Grid>
<Grid Grid.Row="2">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
<ColumnDefinition Width="*" />
</Grid.ColumnDefinitions>
<Button
Grid.Row="2"
Grid.Column="0"
Height="36"
Margin="16,0,8,0"
Command="{Binding UpdateCommand}"
Content="Edit Room"
FontSize="18"
FontWeight="Bold"
Foreground="White"
IsEnabled="{Binding ElementName=RoomsGrid, Path=SelectedItems.Count}"
Style="{StaticResource MaterialDesignRaisedButton}" />
<Button
Grid.Row="2"
Grid.Column="1"
Height="36"
Margin="8"
Command="{Binding DeleteCommand}"
Content="Remove Room"
FontSize="18"
FontWeight="Bold"
Foreground="White"
IsEnabled="{Binding ElementName=RoomsGrid, Path=SelectedItems.Count}"
Style="{StaticResource MaterialDesignRaisedButton}" />
<Button
Grid.Row="2"
Grid.Column="2"
Height="36"
Margin="8,0,16,0"
Command="{Binding CreateCommand}"
Content="Add Room"
FontSize="18"
FontWeight="Bold"
Foreground="White"
Style="{StaticResource MaterialDesignRaisedAccentButton}" />
</Grid>
</Grid>
</UserControl>
的源代码：
RoomView.xaml.cs以及我的using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
namespace Fondok.Views
{
/// <summary>
/// Interaction logic for RoomView.xaml
/// </summary>
public partial class RoomView : UserControl
{
public RoomView()
{
InitializeComponent();
}
void RoomViewLoaded(object sender, RoutedEventArgs e)
{
RoomsGrid.UpdateLayout();
RoomsGrid.Items.Refresh();
}
}
}
{{1}}
答案 0 :(得分：0)
对于ObservableCollection，您可以这样添加：
public ObservableCollection<Room> Rooms
{
get { return _rooms; }
set
{
_rooms = value;
OnPropertyChanged("Rooms");
}
}
添加后刷新，我不明白
答案 1 :(得分：0)
在DatabaseContext上将我的Rooms声明为DbSet而不是ObservableCollection时，是否有可能自动刷新它？
不，至少没有明确更新绑定目标，并且在视图模型的上下文中您不想做任何事情，而该视图模型对绑定一无所知。
如果没有，那么如何在不重写源代码的情况下在我的解决方案上实现ObservableCollection？
每当您在数据库中添加或删除时，都会在ObservableCollection中添加或删除：
class RoomBox : INotifyPropertyChanged
{
private RoomDataInteraction box;
private DatabaseContext db;
private ObservableCollection<Room> _Rooms;
// Rooms BindingList Property
public ObservableCollection<Room> Rooms
{
get
{
return _Rooms;
}
set
{
_Rooms = value;
NotifyPropertyChanged("Rooms");
}
}
// SelectedRoom Property
private Room _selectedRoom;
public Room SelectedRoom
{
get
{
return _selectedRoom;
}
set
{
_selectedRoom = value;
NotifyPropertyChanged("SelectedRoom");
}
}
// RoomBox Constructor
public RoomBox()
{
db = new DatabaseContext();
box = new RoomDataInteraction(db);
Rooms = new ObservableCollection<Room>(box.GetAllRooms());
deleteCommand = new DelegateCommand(DeleteRoom);
updateCommand = new DelegateCommand(UpdateRoom);
createCommand = new DelegateCommand(CreateRoom);
}
// Check if Room Selected?
public bool IsSelected()
{
return SelectedRoom != null;
}
// Implementation Of DeleteCommand Property
private ICommand deleteCommand;
public ICommand DeleteCommand
{
get
{
return deleteCommand;
}
}
// Delete the Selected Room Method & Refresh Rooms Binding :)
public void DeleteRoom()
{
if (!IsSelected())
{
return;
}
box.DeleteRoom(SelectedRoom.RoomID);
Rooms.Delete(SelectedRoom);
}
// Implementation Of UpdateCommand Property
private DelegateCommand updateCommand;
public ICommand UpdateCommand
{
get
{
return updateCommand;
}
}
// Update the Selected Room Method & Refresh Rooms Binding :)
public void UpdateRoom()
{
// Check If Selected?
if (!IsSelected())
{
return;
}
// Create View Model With Selected Room To Edit
RoomViewModel vm = new RoomViewModel(SelectedRoom);
// Run The Room Window And Add Selected Room To Edit & Refresh Binding
if (vm.Run())
{
box.UpdateRoom(SelectedRoom);
}
}
// Implementation Of CreateCommand Property
private DelegateCommand createCommand;
public ICommand CreateCommand
{
get
{
return createCommand;
}
}
// Create Room Method & Refresh Rooms Binding :)
public void CreateRoom()
{
Room create = new Room();
RoomViewModel vm = new RoomViewModel(create);
// Run The Room Window To Create Room & Refresh Binding
if (vm.Run())
{
box.AddRoom(create);
Rooms.Add(create);
}
}
// MVVM NotifyPropertyChanged Implementation
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(string propertyName)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
}