선택한 항목에 바인딩MVVM의 DataGrid 또는 ListBox 항목
선택한 항목을 바인딩해야 하는 WPF에서 약간의 가벼운 읽기를 수행하는 중입니다.데이터 그리드의 항목이지만 구체적인 항목을 찾을 수 없습니다.저는 선택된 개체만 필요합니다.
데이터 그리드:
<DataGrid Grid.Row="5"
Grid.Column="0"
Grid.ColumnSpan="4"
Name="ui_dtgAgreementDocuments"
ItemsSource="{Binding Path=Documents, Mode=TwoWay}"
SelectedItem="{Binding Path=DocumentSelection, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
HorizontalAlignment="Stretch"
VerticalAlignment="Stretch"
Background="White"
SelectionMode="Extended" Margin="2,5"
IsReadOnly="True"
CanUserAddRows="False"
CanUserReorderColumns="False"
CanUserResizeRows="False"
GridLinesVisibility="None"
HorizontalScrollBarVisibility="Hidden"
columnHeaderStyle="{StaticResource GreenTea}"
HeadersVisibility="Column"
BorderThickness="2"
BorderBrush="LightGray"
CellStyle="{StaticResource NonSelectableDataGridCellStyle}"
SelectionUnit="FullRow"
HorizontalContentAlignment="Stretch" AutoGenerateColumns="False">
선택됨항목은 XAML 명령 매개 변수로 바인딩할 수 있습니다.
많은 조사와 검색 끝에, 저는 마침내 이 일반적인 문제에 대한 간단한 해결책을 찾았습니다.
이 작업을 수행하려면 다음 규칙을 모두 따라야 합니다.
Ed Ball의 제안'에 따라 XAML 명령 데이터 바인딩에서 CommandParameter 속성을 정의합니다.이것은 시간이 많이 걸리는 버그입니다.
ICommand의 CanExecute 및 Execute 메서드에 개체 유형의 매개 변수가 있는지 확인합니다.이렇게 하면 데이터 바인딩 명령 매개 변수 유형이 명령 메서드의 매개 변수 유형과 일치하지 않을 때마다 발생하는 사일런트 캐스트 예외를 방지할 수 있습니다.
private bool OnDeleteSelectedItemsCanExecute(object SelectedItems) { // Your code goes here } private bool OnDeleteSelectedItemsExecute(object SelectedItems) { // Your code goes here }
예를 들어, 목록 보기/목록 상자의 선택됨을 전송할 수 있습니다.Items 속성 명령 메서드 또는 목록 보기/목록 상자 자체.좋아요, 그렇지 않나요?
누군가가 내가 한 엄청난 시간을 선택을 받는 방법을 알아내는 데 사용하는 것을 막기를 바랍니다.CanExecute 매개 변수로 사용되는 항목입니다.
에 바인딩할 수 없습니다.SelectedItems
읽기 전용 속성이기 때문입니다.이 문제를 해결하기 위한 MVVM 친화적인 한 가지 방법은IsSelected
의 재산.DataGridRow
.
바인딩은 다음과 같이 설정할 수 있습니다.
<DataGrid ItemsSource="{Binding DocumentViewModels}"
SelectionMode="Extended">
<DataGrid.Resources>
<Style TargetType="DataGridRow">
<Setter Property="IsSelected"
Value="{Binding IsSelected}" />
</Style>
</DataGrid.Resources>
</DataGrid>
그러면 다음을 생성해야 합니다.DocumentViewModel
에서 물려받은ViewModelBase
(또는 사용 중인 MVVM 기본 클래스)의 속성을 가지고 있습니다.Document
데이터 그리드에 표시하고 싶은 데이터 및IsSelected
소유물.
그런 다음 주 뷰 모델에서 다음을 생성합니다.List(Of DocumentViewModel)
불렀다DocumentViewModels
구속력이 있는DataGrid
to. (참고: 목록에서 항목을 추가/제거하려면ObservableCollection(T)
대신.)
자, 여기 까다로운 부분이 있습니다.당신은 그것에 연결할 필요가 있습니다.PropertyChanged
각각의 이벤트DocumentViewModel
목록에서 다음과 같이 표시됩니다.
For Each documentViewModel As DocumentViewModel In DocumentViewModels
documentViewModel.PropertyChanged += DocumentViewModel_PropertyChanged
Next
이를 통해 모든 변경 사항에 대응할 수 있습니다.DocumentViewModel
.
마지막으로.DocumentViewModel_PropertyChanged
당신은 당신의 목록을 반복할 수 있습니다 (또는 Linq 쿼리를 사용합니다).IsSelected = True
.
약간의 속임수를 사용하면 데이터 그리드를 확장하여 바인딩 가능한 버전을 만들 수 있습니다.SelectedItems
소유물.내 솔루션은 바인딩이 필요합니다.Mode=OneWayToSource
어차피 속성에서 읽기만 원하기 때문에 해당 속성을 읽기/쓰기할 수 있도록 솔루션을 확장할 수도 있습니다.
ListBox에도 비슷한 기술이 사용될 수 있을 것으로 생각하지만, 시도해 본 적은 없습니다.
public class BindableMultiSelectDataGrid : DataGrid
{
public static readonly DependencyProperty SelectedItemsProperty =
DependencyProperty.Register("SelectedItems", typeof(IList), typeof(BindableMultiSelectDataGrid), new PropertyMetadata(default(IList)));
public new IList SelectedItems
{
get { return (IList)GetValue(SelectedItemsProperty); }
set { throw new Exception("This property is read-only. To bind to it you must use 'Mode=OneWayToSource'."); }
}
protected override void OnSelectionChanged(SelectionChangedEventArgs e)
{
base.OnSelectionChanged(e);
SetValue(SelectedItemsProperty, base.SelectedItems);
}
}
저는 답을 얻기 위해 이곳에 왔고 많은 훌륭한 답들을 얻었습니다.저는 위의 오마르가 제공한 것과 매우 유사하지만 한 클래스에서 모두 첨부된 숙박시설로 결합했습니다.INOTIFY CollectionChanged 및 목록 전환을 처리합니다.이벤트를 누설하지 않습니다.제가 작성한 것은 코드를 따르는 것이 꽤 간단할 것입니다.C#으로 작성, 선택한 목록 상자를 처리항목 및 데이터Grid가 선택됨항목들.
이것은 DataGrid와 ListBox 모두에서 작동합니다.
(GitHub 사용법을 방금 배웠습니다) GitHub https://github.com/ParrhesiaJoe/SelectedItemsAttachedWpf
사용 방법:
<ListBox ItemsSource="{Binding MyList}" a:Ex.SelectedItems="{Binding ObservableList}"
SelectionMode="Extended"/>
<DataGrid ItemsSource="{Binding MyList}" a:Ex.SelectedItems="{Binding OtherObservableList}" />
그리고 여기 코드가 있습니다.Git에 약간의 샘플이 있습니다.
public class Ex : DependencyObject
{
public static readonly DependencyProperty IsSubscribedToSelectionChangedProperty = DependencyProperty.RegisterAttached(
"IsSubscribedToSelectionChanged", typeof(bool), typeof(Ex), new PropertyMetadata(default(bool)));
public static void SetIsSubscribedToSelectionChanged(DependencyObject element, bool value) { element.SetValue(IsSubscribedToSelectionChangedProperty, value); }
public static bool GetIsSubscribedToSelectionChanged(DependencyObject element) { return (bool)element.GetValue(IsSubscribedToSelectionChangedProperty); }
public static readonly DependencyProperty SelectedItemsProperty = DependencyProperty.RegisterAttached(
"SelectedItems", typeof(IList), typeof(Ex), new PropertyMetadata(default(IList), OnSelectedItemsChanged));
public static void SetSelectedItems(DependencyObject element, IList value) { element.SetValue(SelectedItemsProperty, value); }
public static IList GetSelectedItems(DependencyObject element) { return (IList)element.GetValue(SelectedItemsProperty); }
/// <summary>
/// Attaches a list or observable collection to the grid or listbox, syncing both lists (one way sync for simple lists).
/// </summary>
/// <param name="d">The DataGrid or ListBox</param>
/// <param name="e">The list to sync to.</param>
private static void OnSelectedItemsChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
if (!(d is ListBox || d is MultiSelector))
throw new ArgumentException("Somehow this got attached to an object I don't support. ListBoxes and Multiselectors (DataGrid), people. Geesh =P!");
var selector = (Selector)d;
var oldList = e.OldValue as IList;
if (oldList != null)
{
var obs = oldList as INotifyCollectionChanged;
if (obs != null)
{
obs.CollectionChanged -= OnCollectionChanged;
}
// If we're orphaned, disconnect lb/dg events.
if (e.NewValue == null)
{
selector.SelectionChanged -= OnSelectorSelectionChanged;
SetIsSubscribedToSelectionChanged(selector, false);
}
}
var newList = (IList)e.NewValue;
if (newList != null)
{
var obs = newList as INotifyCollectionChanged;
if (obs != null)
{
obs.CollectionChanged += OnCollectionChanged;
}
PushCollectionDataToSelectedItems(newList, selector);
var isSubscribed = GetIsSubscribedToSelectionChanged(selector);
if (!isSubscribed)
{
selector.SelectionChanged += OnSelectorSelectionChanged;
SetIsSubscribedToSelectionChanged(selector, true);
}
}
}
/// <summary>
/// Initially set the selected items to the items in the newly connected collection,
/// unless the new collection has no selected items and the listbox/grid does, in which case
/// the flow is reversed. The data holder sets the state. If both sides hold data, then the
/// bound IList wins and dominates the helpless wpf control.
/// </summary>
/// <param name="obs">The list to sync to</param>
/// <param name="selector">The grid or listbox</param>
private static void PushCollectionDataToSelectedItems(IList obs, DependencyObject selector)
{
var listBox = selector as ListBox;
if (listBox != null)
{
if (obs.Count > 0)
{
listBox.SelectedItems.Clear();
foreach (var ob in obs) { listBox.SelectedItems.Add(ob); }
}
else
{
foreach (var ob in listBox.SelectedItems) { obs.Add(ob); }
}
return;
}
// Maybe other things will use the multiselector base... who knows =P
var grid = selector as MultiSelector;
if (grid != null)
{
if (obs.Count > 0)
{
grid.SelectedItems.Clear();
foreach (var ob in obs) { grid.SelectedItems.Add(ob); }
}
else
{
foreach (var ob in grid.SelectedItems) { obs.Add(ob); }
}
return;
}
throw new ArgumentException("Somehow this got attached to an object I don't support. ListBoxes and Multiselectors (DataGrid), people. Geesh =P!");
}
/// <summary>
/// When the listbox or grid fires a selectionChanged even, we update the attached list to
/// match it.
/// </summary>
/// <param name="sender">The listbox or grid</param>
/// <param name="e">Items added and removed.</param>
private static void OnSelectorSelectionChanged(object sender, SelectionChangedEventArgs e)
{
var dep = (DependencyObject)sender;
var items = GetSelectedItems(dep);
var col = items as INotifyCollectionChanged;
// Remove the events so we don't fire back and forth, then re-add them.
if (col != null) col.CollectionChanged -= OnCollectionChanged;
foreach (var oldItem in e.RemovedItems) items.Remove(oldItem);
foreach (var newItem in e.AddedItems) items.Add(newItem);
if (col != null) col.CollectionChanged += OnCollectionChanged;
}
/// <summary>
/// When the attached object implements INotifyCollectionChanged, the attached listbox
/// or grid will have its selectedItems adjusted by this handler.
/// </summary>
/// <param name="sender">The listbox or grid</param>
/// <param name="e">The added and removed items</param>
private static void OnCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
// Push the changes to the selected item.
var listbox = sender as ListBox;
if (listbox != null)
{
listbox.SelectionChanged -= OnSelectorSelectionChanged;
if (e.Action == NotifyCollectionChangedAction.Reset) listbox.SelectedItems.Clear();
else
{
foreach (var oldItem in e.OldItems) listbox.SelectedItems.Remove(oldItem);
foreach (var newItem in e.NewItems) listbox.SelectedItems.Add(newItem);
}
listbox.SelectionChanged += OnSelectorSelectionChanged;
}
var grid = sender as MultiSelector;
if (grid != null)
{
grid.SelectionChanged -= OnSelectorSelectionChanged;
if (e.Action == NotifyCollectionChangedAction.Reset) grid.SelectedItems.Clear();
else
{
foreach (var oldItem in e.OldItems) grid.SelectedItems.Remove(oldItem);
foreach (var newItem in e.NewItems) grid.SelectedItems.Add(newItem);
}
grid.SelectionChanged += OnSelectorSelectionChanged;
}
}
}
여기 간단한 해결책이 하나 있습니다.이렇게 하면 View Model에 모든 데이터를 전달/업데이트할 수 있습니다.
Designer.xaml
<DataGrid Grid.Row="1" Name="dgvMain" SelectionChanged="DataGrid_SelectionChanged" />
Designer.cs
ViewModel mModel = null;
public Designer()
{
InitializeComponent();
mModel = new ViewModel();
this.DataContext = mModel;
}
private void DataGrid_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
mModel.SelectedItems = dgvMain.SelectedItems;
}
ViewModel.cs
public class ViewModel
{
public IList SelectedItems { get; set; }
}
저는 제 요구에 맞는 해결책을 사용하여 이 문제를 해결할 수 있습니다.
만들기EventToCommand
에서.ListItemTemplate
MouseUp
그리고 그로서CommandParameter
를 SelectedItems
집수
<i:Interaction.Triggers>
<i:EventTrigger EventName="MouseUp">
<helpers:EventToCommand Command="{Binding DataContext.SelectionChangedUpdate,
RelativeSource={RelativeSource AncestorType=UserControl}}"
CommandParameter="{Binding ElementName=personsList, Path=SelectedItems}" />
</i:EventTrigger>
</i:Interaction.Triggers>
이렇게 하면 나중에 사용할 수 있도록 이를 처리하거나 선택한 항목을 저장하는 명령을 뷰 모델에서 사용할 수 있습니다.즐겁게 코딩하세요.
뷰 모델을 직접 바인딩, 약간 까다로운 버전:
I 명령 만들기:
public class GetSelectedItemsCommand : ICommand
{
public GetSelectedItemsCommand(Action<object> action)
{
_action = action;
}
private readonly Action<object> _action;
public bool CanExecute(object parameter)
{
return true;
}
public event EventHandler CanExecuteChanged;
public void Execute(object parameter)
{
_action(parameter);
}
}
데이터 그리드 생성
<DataGrid x:Name="DataGridOfDesperatePeople" SelectionMode="Extended">
<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectionChanged">
<i:InvokeCommandAction CommandParameter="{Binding ElementName=DataGridOfDesperatePeople, Path=SelectedItems}" Command="{Binding SelectedItemsCommand }" />
</i:EventTrigger>
</i:Interaction.Triggers>
</DataGrid>
뷰 모델에서 작성
public List<YourClassOfItemInTheGrid> SelectedItems { get; set; } = new List<YourClassOfItemInTheGrid>();
public ICommand SelectedItemsCommand
{
get
{
return new GetSelectedItemsCommand(list =>
{
SelectedItems.Clear();
IList items = (IList)list;
IEnumerable<YourClassOfItemInTheGrid> collection = items.Cast<YourClassOfItemInTheGrid>();
SelectedItems = collection.ToList();
});
}
}
가장 쉬운 방법은 SelectionChanged 이벤트에서 ViewModel 속성을 채우는 것이었습니다.
private void MyDataGrid_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
(DataContext as MyViewModel).SelectedItems.Clear();
(DataContext as MyViewModel).SelectedItems.AddRange(MyDataGrid.SelectedItems.OfType<ItemType>());
}
저는 이 게시물이 조금 오래되어 답변을 받은 것으로 알고 있습니다.하지만 저는 MVVM이 아닌 답을 생각해냈습니다.그것은 쉽고 저에게 효과가 있습니다.Selected Collection(선택된 컬렉션)을 Selected Results(선택된 결과)로 가정하여 다른 DataGrid를 추가합니다.
<DataGrid x:Name="SelectedGridRows"
ItemsSource="{Binding SelectedResults,Mode=OneWayToSource}"
Visibility="Collapsed" >
코드 뒤에 다음을 생성자에 추가합니다.
public ClassConstructor()
{
InitializeComponent();
OriginalGrid.SelectionChanged -= OriginalGrid_SelectionChanged;
OriginalGrid.SelectionChanged += OriginalGrid_SelectionChanged;
}
private void OriginalGrid_SelectionChanged(object sender,
SelectionChangedEventArgs e)
{
SelectedGridRows.ItemsSource = OriginalGrid.SelectedItems;
}
이 문제는 WPF 문제 대기열에서 "향상"으로 분류되었습니다.
https://github.com/dotnet/wpf/issues/3140
아마도 최종적으로 수정/업데이트가 이루어질 것이고 솔루션이 즉시 통합될 것입니다.
이렇게 하면 됩니다.
다중 선택기 동작.vb
Imports System.Collections
Imports System.Windows
Imports System.Windows.Controls.Primitives
Imports System.Windows.Controls
Imports System
Public NotInheritable Class MultiSelectorBehaviours
Private Sub New()
End Sub
Public Shared ReadOnly SynchronizedSelectedItems As DependencyProperty = _
DependencyProperty.RegisterAttached("SynchronizedSelectedItems", GetType(IList), GetType(MultiSelectorBehaviours), New PropertyMetadata(Nothing, New PropertyChangedCallback(AddressOf OnSynchronizedSelectedItemsChanged)))
Private Shared ReadOnly SynchronizationManagerProperty As DependencyProperty = DependencyProperty.RegisterAttached("SynchronizationManager", GetType(SynchronizationManager), GetType(MultiSelectorBehaviours), New PropertyMetadata(Nothing))
''' <summary>
''' Gets the synchronized selected items.
''' </summary>
''' <param name="dependencyObject">The dependency object.</param>
''' <returns>The list that is acting as the sync list.</returns>
Public Shared Function GetSynchronizedSelectedItems(ByVal dependencyObject As DependencyObject) As IList
Return DirectCast(dependencyObject.GetValue(SynchronizedSelectedItems), IList)
End Function
''' <summary>
''' Sets the synchronized selected items.
''' </summary>
''' <param name="dependencyObject">The dependency object.</param>
''' <param name="value">The value to be set as synchronized items.</param>
Public Shared Sub SetSynchronizedSelectedItems(ByVal dependencyObject As DependencyObject, ByVal value As IList)
dependencyObject.SetValue(SynchronizedSelectedItems, value)
End Sub
Private Shared Function GetSynchronizationManager(ByVal dependencyObject As DependencyObject) As SynchronizationManager
Return DirectCast(dependencyObject.GetValue(SynchronizationManagerProperty), SynchronizationManager)
End Function
Private Shared Sub SetSynchronizationManager(ByVal dependencyObject As DependencyObject, ByVal value As SynchronizationManager)
dependencyObject.SetValue(SynchronizationManagerProperty, value)
End Sub
Private Shared Sub OnSynchronizedSelectedItemsChanged(ByVal dependencyObject As DependencyObject, ByVal e As DependencyPropertyChangedEventArgs)
If e.OldValue IsNot Nothing Then
Dim synchronizer As SynchronizationManager = GetSynchronizationManager(dependencyObject)
synchronizer.StopSynchronizing()
SetSynchronizationManager(dependencyObject, Nothing)
End If
Dim list As IList = TryCast(e.NewValue, IList)
Dim selector As Selector = TryCast(dependencyObject, Selector)
' check that this property is an IList, and that it is being set on a ListBox
If list IsNot Nothing AndAlso selector IsNot Nothing Then
Dim synchronizer As SynchronizationManager = GetSynchronizationManager(dependencyObject)
If synchronizer Is Nothing Then
synchronizer = New SynchronizationManager(selector)
SetSynchronizationManager(dependencyObject, synchronizer)
End If
synchronizer.StartSynchronizingList()
End If
End Sub
''' <summary>
''' A synchronization manager.
''' </summary>
Private Class SynchronizationManager
Private ReadOnly _multiSelector As Selector
Private _synchronizer As TwoListSynchronizer
''' <summary>
''' Initializes a new instance of the <see cref="SynchronizationManager"/> class.
''' </summary>
''' <param name="selector">The selector.</param>
Friend Sub New(ByVal selector As Selector)
_multiSelector = selector
End Sub
''' <summary>
''' Starts synchronizing the list.
''' </summary>
Public Sub StartSynchronizingList()
Dim list As IList = GetSynchronizedSelectedItems(_multiSelector)
If list IsNot Nothing Then
_synchronizer = New TwoListSynchronizer(GetSelectedItemsCollection(_multiSelector), list)
_synchronizer.StartSynchronizing()
End If
End Sub
''' <summary>
''' Stops synchronizing the list.
''' </summary>
Public Sub StopSynchronizing()
_synchronizer.StopSynchronizing()
End Sub
Public Shared Function GetSelectedItemsCollection(ByVal selector As Selector) As IList
If TypeOf selector Is MultiSelector Then
Return TryCast(selector, MultiSelector).SelectedItems
ElseIf TypeOf selector Is ListBox Then
Return TryCast(selector, ListBox).SelectedItems
Else
Throw New InvalidOperationException("Target object has no SelectedItems property to bind.")
End If
End Function
End Class
End Class
ItemConverter.vb 목록
''' <summary>
''' Converts items in the Master list to Items in the target list, and back again.
''' </summary>
Public Interface IListItemConverter
''' <summary>
''' Converts the specified master list item.
''' </summary>
''' <param name="masterListItem">The master list item.</param>
''' <returns>The result of the conversion.</returns>
Function Convert(ByVal masterListItem As Object) As Object
''' <summary>
''' Converts the specified target list item.
''' </summary>
''' <param name="targetListItem">The target list item.</param>
''' <returns>The result of the conversion.</returns>
Function ConvertBack(ByVal targetListItem As Object) As Object
End Interface
TwoListSynchronizer.vb
Imports System.Collections
Imports System.Collections.Specialized
Imports System.Linq
Imports System.Windows
''' <summary>
''' Keeps two lists synchronized.
''' </summary>
Public Class TwoListSynchronizer
Implements IWeakEventListener
Private Shared ReadOnly DefaultConverter As IListItemConverter = New DoNothingListItemConverter()
Private ReadOnly _masterList As IList
Private ReadOnly _masterTargetConverter As IListItemConverter
Private ReadOnly _targetList As IList
''' <summary>
''' Initializes a new instance of the <see cref="TwoListSynchronizer"/> class.
''' </summary>
''' <param name="masterList">The master list.</param>
''' <param name="targetList">The target list.</param>
''' <param name="masterTargetConverter">The master-target converter.</param>
Public Sub New(ByVal masterList As IList, ByVal targetList As IList, ByVal masterTargetConverter As IListItemConverter)
_masterList = masterList
_targetList = targetList
_masterTargetConverter = masterTargetConverter
End Sub
''' <summary>
''' Initializes a new instance of the <see cref="TwoListSynchronizer"/> class.
''' </summary>
''' <param name="masterList">The master list.</param>
''' <param name="targetList">The target list.</param>
Public Sub New(ByVal masterList As IList, ByVal targetList As IList)
Me.New(masterList, targetList, DefaultConverter)
End Sub
Private Delegate Sub ChangeListAction(ByVal list As IList, ByVal e As NotifyCollectionChangedEventArgs, ByVal converter As Converter(Of Object, Object))
''' <summary>
''' Starts synchronizing the lists.
''' </summary>
Public Sub StartSynchronizing()
ListenForChangeEvents(_masterList)
ListenForChangeEvents(_targetList)
' Update the Target list from the Master list
SetListValuesFromSource(_masterList, _targetList, AddressOf ConvertFromMasterToTarget)
' In some cases the target list might have its own view on which items should included:
' so update the master list from the target list
' (This is the case with a ListBox SelectedItems collection: only items from the ItemsSource can be included in SelectedItems)
If Not TargetAndMasterCollectionsAreEqual() Then
SetListValuesFromSource(_targetList, _masterList, AddressOf ConvertFromTargetToMaster)
End If
End Sub
''' <summary>
''' Stop synchronizing the lists.
''' </summary>
Public Sub StopSynchronizing()
StopListeningForChangeEvents(_masterList)
StopListeningForChangeEvents(_targetList)
End Sub
''' <summary>
''' Receives events from the centralized event manager.
''' </summary>
''' <param name="managerType">The type of the <see cref="T:System.Windows.WeakEventManager"/> calling this method.</param>
''' <param name="sender">Object that originated the event.</param>
''' <param name="e">Event data.</param>
''' <returns>
''' true if the listener handled the event. It is considered an error by the <see cref="T:System.Windows.WeakEventManager"/> handling in WPF to register a listener for an event that the listener does not handle. Regardless, the method should return false if it receives an event that it does not recognize or handle.
''' </returns>
Public Function ReceiveWeakEvent(ByVal managerType As Type, ByVal sender As Object, ByVal e As EventArgs) As Boolean Implements System.Windows.IWeakEventListener.ReceiveWeakEvent
HandleCollectionChanged(TryCast(sender, IList), TryCast(e, NotifyCollectionChangedEventArgs))
Return True
End Function
''' <summary>
''' Listens for change events on a list.
''' </summary>
''' <param name="list">The list to listen to.</param>
Protected Sub ListenForChangeEvents(ByVal list As IList)
If TypeOf list Is INotifyCollectionChanged Then
CollectionChangedEventManager.AddListener(TryCast(list, INotifyCollectionChanged), Me)
End If
End Sub
''' <summary>
''' Stops listening for change events.
''' </summary>
''' <param name="list">The list to stop listening to.</param>
Protected Sub StopListeningForChangeEvents(ByVal list As IList)
If TypeOf list Is INotifyCollectionChanged Then
CollectionChangedEventManager.RemoveListener(TryCast(list, INotifyCollectionChanged), Me)
End If
End Sub
Private Sub AddItems(ByVal list As IList, ByVal e As NotifyCollectionChangedEventArgs, ByVal converter As Converter(Of Object, Object))
Dim itemCount As Integer = e.NewItems.Count
For i As Integer = 0 To itemCount - 1
Dim insertionPoint As Integer = e.NewStartingIndex + i
If insertionPoint > list.Count Then
list.Add(converter(e.NewItems(i)))
Else
list.Insert(insertionPoint, converter(e.NewItems(i)))
End If
Next
End Sub
Private Function ConvertFromMasterToTarget(ByVal masterListItem As Object) As Object
Return If(_masterTargetConverter Is Nothing, masterListItem, _masterTargetConverter.Convert(masterListItem))
End Function
Private Function ConvertFromTargetToMaster(ByVal targetListItem As Object) As Object
Return If(_masterTargetConverter Is Nothing, targetListItem, _masterTargetConverter.ConvertBack(targetListItem))
End Function
Private Sub HandleCollectionChanged(ByVal sender As Object, ByVal e As NotifyCollectionChangedEventArgs)
Dim sourceList As IList = TryCast(sender, IList)
Select Case e.Action
Case NotifyCollectionChangedAction.Add
PerformActionOnAllLists(AddressOf AddItems, sourceList, e)
Exit Select
Case NotifyCollectionChangedAction.Move
PerformActionOnAllLists(AddressOf MoveItems, sourceList, e)
Exit Select
Case NotifyCollectionChangedAction.Remove
PerformActionOnAllLists(AddressOf RemoveItems, sourceList, e)
Exit Select
Case NotifyCollectionChangedAction.Replace
PerformActionOnAllLists(AddressOf ReplaceItems, sourceList, e)
Exit Select
Case NotifyCollectionChangedAction.Reset
UpdateListsFromSource(TryCast(sender, IList))
Exit Select
Case Else
Exit Select
End Select
End Sub
Private Sub MoveItems(ByVal list As IList, ByVal e As NotifyCollectionChangedEventArgs, ByVal converter As Converter(Of Object, Object))
RemoveItems(list, e, converter)
AddItems(list, e, converter)
End Sub
Private Sub PerformActionOnAllLists(ByVal action As ChangeListAction, ByVal sourceList As IList, ByVal collectionChangedArgs As NotifyCollectionChangedEventArgs)
If sourceList Is _masterList Then
PerformActionOnList(_targetList, action, collectionChangedArgs, AddressOf ConvertFromMasterToTarget)
Else
PerformActionOnList(_masterList, action, collectionChangedArgs, AddressOf ConvertFromTargetToMaster)
End If
End Sub
Private Sub PerformActionOnList(ByVal list As IList, ByVal action As ChangeListAction, ByVal collectionChangedArgs As NotifyCollectionChangedEventArgs, ByVal converter As Converter(Of Object, Object))
StopListeningForChangeEvents(list)
action(list, collectionChangedArgs, converter)
ListenForChangeEvents(list)
End Sub
Private Sub RemoveItems(ByVal list As IList, ByVal e As NotifyCollectionChangedEventArgs, ByVal converter As Converter(Of Object, Object))
Dim itemCount As Integer = e.OldItems.Count
' for the number of items being removed, remove the item from the Old Starting Index
' (this will cause following items to be shifted down to fill the hole).
For i As Integer = 0 To itemCount - 1
list.RemoveAt(e.OldStartingIndex)
Next
End Sub
Private Sub ReplaceItems(ByVal list As IList, ByVal e As NotifyCollectionChangedEventArgs, ByVal converter As Converter(Of Object, Object))
RemoveItems(list, e, converter)
AddItems(list, e, converter)
End Sub
Private Sub SetListValuesFromSource(ByVal sourceList As IList, ByVal targetList As IList, ByVal converter As Converter(Of Object, Object))
StopListeningForChangeEvents(targetList)
targetList.Clear()
For Each o As Object In sourceList
targetList.Add(converter(o))
Next
ListenForChangeEvents(targetList)
End Sub
Private Function TargetAndMasterCollectionsAreEqual() As Boolean
Return _masterList.Cast(Of Object)().SequenceEqual(_targetList.Cast(Of Object)().[Select](Function(item) ConvertFromTargetToMaster(item)))
End Function
''' <summary>
''' Makes sure that all synchronized lists have the same values as the source list.
''' </summary>
''' <param name="sourceList">The source list.</param>
Private Sub UpdateListsFromSource(ByVal sourceList As IList)
If sourceList Is _masterList Then
SetListValuesFromSource(_masterList, _targetList, AddressOf ConvertFromMasterToTarget)
Else
SetListValuesFromSource(_targetList, _masterList, AddressOf ConvertFromTargetToMaster)
End If
End Sub
''' <summary>
''' An implementation that does nothing in the conversions.
''' </summary>
Friend Class DoNothingListItemConverter
Implements IListItemConverter
''' <summary>
''' Converts the specified master list item.
''' </summary>
''' <param name="masterListItem">The master list item.</param>
''' <returns>The result of the conversion.</returns>
Public Function Convert(ByVal masterListItem As Object) As Object Implements IListItemConverter.Convert
Return masterListItem
End Function
''' <summary>
''' Converts the specified target list item.
''' </summary>
''' <param name="targetListItem">The target list item.</param>
''' <returns>The result of the conversion.</returns>
Public Function ConvertBack(ByVal targetListItem As Object) As Object Implements IListItemConverter.ConvertBack
Return targetListItem
End Function
End Class
End Class
그러면 XAML의 경우:
<DataGrid ..... local:MultiSelectorBehaviours.SynchronizedSelectedItems="{Binding SelectedResults}" />
마지막으로 VM:
Public ReadOnly Property SelectedResults As ObservableCollection(Of StatisticsResultModel)
Get
Return _objSelectedResults
End Get
End Property
신용 거래처: http://blog.functionalfun.net/2009/02/how-to-databind-to-selecteditems.html
변환기를 사용하는 것은 어떻습니까?
public class SelectedItemsConverter : IValueConverter
{
public object Convert(object value, Type targetType, object parameter, CultureInfo culture)
{
var dg = value as DataGrid;
return dg?.SelectedItems;
}
...
에서사에 합니다.DataGrid
의ContextMenu
다음과 같이:
<DataGrid.ContextMenu>
<ContextMenu>
<MenuItem
CommandParameter="{Binding Path=MySelectedItems, Converter={StaticResource selectedItemsConverter}, Mode=OneWay, RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type ContextMenu}}}"
Command="{Binding MyDoSomethingWithMySelectedItemsCommand}"
Header="Do Something...">
</MenuItem>
devuxer가 언급한 솔루션
<DataGrid.Resources>
<Style TargetType="DataGridRow">
<Setter Property="IsSelected"
Value="{Binding IsSelected}" />
</Style>
</DataGrid.Resources>
데이터 집합이 큰 경우에는 작동하지 않습니다.행 가상화를 사용하지 않도록 설정해야 합니다. 필요한 경우 바로 이를 사용할 수 있습니다.
행 가상화 사용="거짓"
언급URL : https://stackoverflow.com/questions/9880589/bind-to-selecteditems-from-datagrid-or-listbox-in-mvvm
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