C# WPF数据网格多选
我已经读过几篇关于这个主题的文章，但很多都是来自VS或framework的早期版本。我试图做的是从dataGrid中选择多行，并将这些行返回到绑定的可观察集合中 我曾尝试创建一个属性（类型）并将其添加到一个可观察的集合中，它可以处理单个记录，但代码从来不会处理多个记录 在VS2013中，是否有一种干净的方法可以使用MVVM模式实现这一点 如有任何想法，将不胜感激C# WPF数据网格多选,c#,wpf,mvvm,datagrid,C#,Wpf,Mvvm,Datagrid,我已经读过几篇关于这个主题的文章，但很多都是来自VS或framework的早期版本。我试图做的是从dataGrid中选择多行，并将这些行返回到绑定的可观察集合中 我曾尝试创建一个属性（类型）并将其添加到一个可观察的集合中，它可以处理单个记录，但代码从来不会处理多个记录 在VS2013中，是否有一种干净的方法可以使用MVVM模式实现这一点 如有任何想法，将不胜感激 <DataGrid x:Name="MainDataGrid" Height="390" Width="720"
<DataGrid x:Name="MainDataGrid" Height="390" Width="720"
VerticalAlignment="Center" CanUserAddRows="False" CanUserDeleteRows="False" AutoGenerateColumns="False"
ItemsSource="{Binding Path=DisplayInDataGrid}"
SelectedItem="{Binding Path=DataGridItemSelected}"
SelectionMode="Extended"
private ObservableCollection<ScannedItem> _dataGridItemsSelected;
public ObservableCollection<ScannedItem> DataGridItemsSelected
{
get { return _dataGridItemsSelected; }
set
{
_dataGridItemsSelected = value;
OnPropertyChanged("DataGridItemsSelected");
}
}
private ScannedItem _dataGridItemSelected;
public ScannedItem DataGridItemSelected
{
get { return _dataGridItemSelected;}
set
{
_dataGridItemSelected = value;
OnPropertyChanged("DataGridItemSelected");
EnableButtons();
LoadSelectedCollection(DataGridItemSelected);
}
}
void LoadSelectedCollection(ScannedItem si)
{
if (DataGridItemsSelected == null)
{
DataGridItemsSelected = new ObservableCollection<ScannedItem>();
}
DataGridItemsSelected.Add(si);
}
创建一个命令，在DataGrid
的SelectionChanged
事件上触发，并传入DataGrid'
sSelectedItems
在ViewModel中，具有选定对象的列表
然后，您的SelectionChangedCommand
执行方法将更新所选对象的集合
例如：
在我的XAML中：
<DataGrid ItemsSource="{Binding Datasets, NotifyOnTargetUpdated=True}" Name="dsDatagrid" SelectionMode="Extended" MouseDoubleClick="ViewDataset">
<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectionChanged">
<cmd:EventToCommand Command="{Binding SelectionChangedCommand}" CommandParameter="{Binding ElementName=dsDatagrid, Path=SelectedItems}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
</DataGrid>
在我的ViewModel中：
私有列表选择的数据集
private void SelectionChangedExecuted(object datasets)
{
this.selectedDatasets = new List<ObservableDataset>((datasets as IList).Cast<ObservableDataset>());
}
private void SelectionChangedExecuted（对象数据集）
{
this.selectedDatasets=新列表（（数据集为IList.Cast（））；
}
编辑：我正在使用MVVMLight。我已经使用附加的行为模式为属性实现了双向数据绑定
下图显示了它的工作原理：
有两个数据网格绑定到同一个模型，它们共享选定的项。左侧数据网格处于活动状态，因此选定项为蓝色；右侧数据网格处于非活动状态，因此选定项为灰色
下面是如何使用它的示例代码：
main window.xaml
<Window x:Class="WpfApplication.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:WpfApplication"
Title="MainWindow" Height="350" Width="525">
<Window.DataContext>
<local:MainWindowModel/>
</Window.DataContext>
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition Height="Auto"/>
</Grid.RowDefinitions>
<DataGrid ItemsSource="{Binding People}" local:MultiSelectorExtension.SelectedItems="{Binding SelectedPeople}" CanUserAddRows="True"/>
<DataGrid Grid.Column="1" ItemsSource="{Binding People}" local:MultiSelectorExtension.SelectedItems="{Binding SelectedPeople}" CanUserAddRows="True"/>
<StackPanel Grid.Row="1" Grid.ColumnSpan="2">
<Button DockPanel.Dock="Top" Content="Select All" Command="{Binding SelectAllCommand}"/>
<Button DockPanel.Dock="Top" Content="Unselect All" Command="{Binding UnselectAllCommand}"/>
<Button DockPanel.Dock="Top" Content="Select Next Range" Command="{Binding SelectNextRangeCommand}"/>
</StackPanel>
</Grid>
</Window>
Model.cs
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Diagnostics;
using System.Linq;
using System.Windows.Input;
namespace WpfApplication
{
abstract class ObservableObject : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(PropertyChangedEventArgs e)
{
var handler = this.PropertyChanged;
if (handler != null)
handler(this, e);
}
protected void Set<T>(ref T field, T value, string propertyName)
{
if (!EqualityComparer<T>.Default.Equals(field, value))
{
field = value;
this.OnPropertyChanged(new PropertyChangedEventArgs(propertyName));
}
}
}
sealed class DelegateCommand : ICommand
{
private readonly Action action;
public DelegateCommand(Action action)
{
if (action == null)
throw new ArgumentNullException("action");
this.action = action;
}
public event EventHandler CanExecuteChanged
{
add { CommandManager.RequerySuggested += value; }
remove { CommandManager.RequerySuggested -= value; }
}
public void Execute()
{
this.action();
}
bool ICommand.CanExecute(object parameter)
{
return true;
}
void ICommand.Execute(object parameter)
{
this.Execute();
}
}
class Person : ObservableObject
{
private string name, surname;
public Person()
{
}
public Person(string name, string surname)
{
this.name = name;
this.surname = surname;
}
public string Name
{
get { return this.name; }
set { this.Set(ref this.name, value, "Name"); }
}
public string Surname
{
get { return this.surname; }
set { this.Set(ref this.surname, value, "Surname"); }
}
public override string ToString()
{
return this.name + ' ' + this.surname;
}
}
class MainWindowModel : ObservableObject
{
public ObservableCollection<Person> People { get; private set; }
public SelectedItemCollection<Person> SelectedPeople { get; private set; }
public DelegateCommand SelectAllCommand { get; private set; }
public DelegateCommand UnselectAllCommand { get; private set; }
public DelegateCommand SelectNextRangeCommand { get; private set; }
public MainWindowModel()
{
this.People = new ObservableCollection<Person>(Enumerable.Range(1, 1000).Select(i => new Person("Name " + i, "Surname " + i)));
this.SelectedPeople = new SelectedItemCollection<Person>();
for (int i = 0; i < this.People.Count; i += 2)
this.SelectedPeople.Add(this.People[i]);
this.SelectAllCommand = new DelegateCommand(() => this.SelectedPeople.Reset(this.People));
this.UnselectAllCommand = new DelegateCommand(() => this.SelectedPeople.Clear());
this.SelectNextRangeCommand = new DelegateCommand(() =>
{
var index = this.SelectedPeople.Count > 0 ? this.People.IndexOf(this.SelectedPeople[this.SelectedPeople.Count - 1]) + 1 : 0;
int count = 10;
this.SelectedPeople.Reset(Enumerable.Range(index, count).Where(i => i < this.People.Count).Select(i => this.People[i]));
});
this.SelectedPeople.CollectionChanged += this.OnSelectedPeopleCollectionChanged;
}
private void OnSelectedPeopleCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
Debug.WriteLine("Action = {0}, NewItems.Count = {1}, NewStartingIndex = {2}, OldItems.Count = {3}, OldStartingIndex = {4}, Total.Count = {5}", e.Action, e.NewItems != null ? e.NewItems.Count : 0, e.NewStartingIndex, e.OldItems != null ? e.OldItems.Count : 0, e.OldStartingIndex, this.SelectedPeople.Count);
}
}
class SelectedItemCollection<T> : ObservableCollection<T>
{
public void Reset(IEnumerable<T> items)
{
int oldCount = this.Count;
this.Items.Clear();
foreach (var item in items)
this.Items.Add(item);
if (!(oldCount == 0 && this.Count == 0))
{
this.OnCollectionChanged(new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
if (this.Count != oldCount)
this.OnPropertyChanged(new PropertyChangedEventArgs("Count"));
this.OnPropertyChanged(new PropertyChangedEventArgs("Item[]"));
}
}
}
}
使用系统；
使用System.Collections.Generic；
使用System.Collections.ObjectModel；
使用System.Collections.Specialized；
使用系统组件模型；
使用系统诊断；
使用System.Linq；
使用System.Windows.Input；
命名空间WpfApplication
{
抽象类ObserveObject:INotifyPropertyChanged
{
公共事件属性更改事件处理程序属性更改；
PropertyChanged上受保护的虚拟无效（PropertyChangedEventArgs e）
{
var handler=this.PropertyChanged；
if（处理程序！=null）
处理者（本，e）；
}
受保护的无效集（参考T字段、T值、字符串propertyName）
{
如果（！EqualityComparer.Default.Equals（字段，值））
{
字段=值；
this.OnPropertyChanged（新PropertyChangedEventArgs（propertyName））；
}
}
}
密封类DelegateCommand:ICommand
{
私人只读操作；
公共委托人命令（操作）
{
if（action==null）
抛出新的异常（“操作”）；
这个动作=动作；
}
公共事件事件处理程序CanExecuteChanged
{
添加{CommandManager.RequerySuggested+=value；}
删除{CommandManager.RequerySuggested-=value；}
}
public void Execute（）
{
这个动作（）；
}
bool ICommand.CanExecute（对象参数）
{
返回true；
}
void ICommand.Execute（对象参数）
{
这是Execute（）；
}
}
类人：ObservieObject
{
私有字符串名称、姓氏；
公众人士（）
{
}
公众人物（字符串名称、字符串姓氏）
{
this.name=名称；
this.姓氏=姓氏；
}
公共字符串名
{
获取{返回this.name；}
set{this.set（ref this.name，value，“name”）；}
}
公共字符串姓氏
{
获取{返回this.name；}
set{this.set（参考this.names，值，“姓氏”）；}
}
公共重写字符串ToString（）
{
返回this.name+“”+this.姓氏；
}
}
类MainWindowModel:ObservableObject
{
公共可观察集合人员{get；private set；}
public SelectedItemCollection SelectedPeople{get；private set；}
public DelegateCommand SelectAllCommand{get；private set；}
public DelegateCommand UnselectAllCommand{get；private set；}
public DelegateCommand SelectNextRangeCommand{get；private set；}
公共主窗口模型（）
{
this.People=newobserveCollection（Enumerable.Range（11000）.Select（i=>newperson（“Name”+i，“姓氏”+i））；
this.SelectedPeople=new SelectedItemCollection（）；
for（int i=0；ithis.SelectedPeople.Reset（this.People））；
this.UnselectAllCommand=newdelegatecommand（（）=>this.SelectedPeople.Clear（））；
this.SelectNextRangeCommand=new DelegateCommand（（）=>
{
var index=this.SelectedPeople.Count>0？this.People.IndexOf（this.SelectedPeople[this.SelectedPeople.Count-1]）+1:0；
整数计数=10；
this.SelectedPeople.Reset（Enumerable.Range（index，count）.Where（i=>ithis.People[i]）；
});
this.SelectedPeople.CollectionChanged+=this.OnSelectedPeopleCollectionChanged；
}
SelectedPeopleCollectionChanged上的私有无效（对象发送方，NotifyCollectionChangedEventArgs e）
{
Debug.WriteLine（“Action={0}，NewItems.Count={1}，NewStartingIndex={2}，OldItems.Count={3}，OldStartingIndex={4}，Total.Count={
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Linq;
using System.Reflection;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Data;
using System.Windows.Markup;
namespace WpfApplication
{
static class MultiSelectorExtension
{
public static readonly DependencyProperty SelectedItemsProperty = DependencyProperty.RegisterAttached("SelectedItems", typeof(IList), typeof(MultiSelectorExtension), new PropertyMetadata(new PropertyChangedCallback(OnSelectedItemsChanged)));
private static readonly DependencyProperty SelectedItemsBinderProperty = DependencyProperty.RegisterAttached("SelectedItemsBinder", typeof(SelectedItemsBinder), typeof(MultiSelectorExtension));
[AttachedPropertyBrowsableForType(typeof(MultiSelector))]
[DependsOn("ItemsSource")]
public static IList GetSelectedItems(this MultiSelector multiSelector)
{
if (multiSelector == null)
throw new ArgumentNullException("multiSelector");
return (IList)multiSelector.GetValue(SelectedItemsProperty);
}
public static void SetSelectedItems(this MultiSelector multiSelector, IList selectedItems)
{
if (multiSelector == null)
throw new ArgumentNullException("multiSelector");
multiSelector.SetValue(SelectedItemsProperty, selectedItems);
}
private static void OnSelectedItemsChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
var multiSelector = d as MultiSelector;
if (multiSelector == null)
return;
var binder = (SelectedItemsBinder)multiSelector.GetValue(SelectedItemsBinderProperty);
var selectedItems = e.NewValue as IList;
if (selectedItems != null)
{
if (binder == null)
binder = new SelectedItemsBinder(multiSelector);
binder.SelectedItems = selectedItems;
}
else if (binder != null)
binder.Dispose();
}
private sealed class SelectedItemsBinder : IDisposable
{
private static readonly IList emptyList = new object[0];
private static readonly Action<MultiSelector> multiSelectorBeginUpdateSelectedItems, multiSelectorEndUpdateSelectedItems;
private readonly MultiSelector multiSelector;
private IList selectedItems;
private IResetter selectedItemsResetter;
private bool suspendMultiSelectorUpdate, suspendSelectedItemsUpdate;
static SelectedItemsBinder()
{
GetMultiSelectorBeginEndUpdateSelectedItems(out multiSelectorBeginUpdateSelectedItems, out multiSelectorEndUpdateSelectedItems);
}
public SelectedItemsBinder(MultiSelector multiSelector)
{
this.multiSelector = multiSelector;
this.multiSelector.SelectionChanged += this.OnMultiSelectorSelectionChanged;
this.multiSelector.Unloaded += this.OnMultiSelectorUnloaded;
this.multiSelector.SetValue(SelectedItemsBinderProperty, this);
}
public IList SelectedItems
{
get { return this.selectedItems; }
set
{
this.SetSelectedItemsChangedHandler(false);
this.selectedItems = value;
this.selectedItemsResetter = GetResetter(this.selectedItems.GetType());
this.SetSelectedItemsChangedHandler(true);
if (this.multiSelector.IsLoaded)
this.OnSelectedItemsCollectionChanged(this.selectedItems, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
else
{
RoutedEventHandler multiSelectorLoadedHandler = null;
this.multiSelector.Loaded += multiSelectorLoadedHandler = new RoutedEventHandler((sender, e) =>
{
this.OnSelectedItemsCollectionChanged(this.selectedItems, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset));
this.multiSelector.Loaded -= multiSelectorLoadedHandler;
});
}
}
}
private int ItemsSourceCount
{
get
{
var collection = this.multiSelector.ItemsSource as ICollection;
return collection != null ? collection.Count : -1;
}
}
public void Dispose()
{
this.multiSelector.ClearValue(SelectedItemsBinderProperty);
this.multiSelector.Unloaded -= this.OnMultiSelectorUnloaded;
this.multiSelector.SelectionChanged -= this.OnMultiSelectorSelectionChanged;
this.SetSelectedItemsChangedHandler(false);
}
private void OnSelectedItemsCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
if (this.suspendMultiSelectorUpdate || e.Action == NotifyCollectionChangedAction.Move)
return;
this.suspendSelectedItemsUpdate = true;
if (this.selectedItems.Count == 0)
this.multiSelector.UnselectAll();
else if (this.selectedItems.Count == this.ItemsSourceCount)
this.multiSelector.SelectAll();
else if (e.Action != NotifyCollectionChangedAction.Reset && (e.NewItems == null || e.NewItems.Count <= 1) && (e.OldItems == null || e.OldItems.Count <= 1))
UpdateList(this.multiSelector.SelectedItems, e.NewItems ?? emptyList, e.OldItems ?? emptyList);
else
{
if (multiSelectorBeginUpdateSelectedItems != null)
{
multiSelectorBeginUpdateSelectedItems(this.multiSelector);
this.multiSelector.SelectedItems.Clear();
UpdateList(this.multiSelector.SelectedItems, this.selectedItems, emptyList);
multiSelectorEndUpdateSelectedItems(this.multiSelector);
}
else
{
this.multiSelector.UnselectAll();
UpdateList(this.multiSelector.SelectedItems, this.selectedItems, emptyList);
}
}
this.suspendSelectedItemsUpdate = false;
}
private void OnMultiSelectorSelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (this.suspendSelectedItemsUpdate)
return;
this.suspendMultiSelectorUpdate = true;
if (e.AddedItems.Count <= 1 && e.RemovedItems.Count <= 1)
UpdateList(this.selectedItems, e.AddedItems, e.RemovedItems);
else
{
if (this.selectedItemsResetter != null)
this.selectedItemsResetter.Reset(this.selectedItems, this.multiSelector.SelectedItems.Cast<object>().Where(item => item != CollectionView.NewItemPlaceholder));
else
UpdateList(this.selectedItems, e.AddedItems, e.RemovedItems);
}
this.suspendMultiSelectorUpdate = false;
}
private void OnMultiSelectorUnloaded(object sender, RoutedEventArgs e)
{
this.Dispose();
}
private void SetSelectedItemsChangedHandler(bool add)
{
var notifyCollectionChanged = this.selectedItems as INotifyCollectionChanged;
if (notifyCollectionChanged != null)
{
if (add)
notifyCollectionChanged.CollectionChanged += this.OnSelectedItemsCollectionChanged;
else
notifyCollectionChanged.CollectionChanged -= this.OnSelectedItemsCollectionChanged;
}
}
private static void UpdateList(IList list, IList newItems, IList oldItems)
{
int addedCount = 0;
for (int i = 0; i < oldItems.Count; ++i)
{
var index = list.IndexOf(oldItems[i]);
if (index >= 0)
{
object newItem;
if (i < newItems.Count && (newItem = newItems[i]) != CollectionView.NewItemPlaceholder)
{
list[index] = newItem;
++addedCount;
}
else
list.RemoveAt(index);
}
}
for (int i = addedCount; i < newItems.Count; ++i)
{
var newItem = newItems[i];
if (newItem != CollectionView.NewItemPlaceholder)
list.Add(newItem);
}
}
private static void GetMultiSelectorBeginEndUpdateSelectedItems(out Action<MultiSelector> beginUpdateSelectedItems, out Action<MultiSelector> endUpdateSelectedItems)
{
try
{
beginUpdateSelectedItems = (Action<MultiSelector>)Delegate.CreateDelegate(typeof(Action<MultiSelector>), typeof(MultiSelector).GetMethod("BeginUpdateSelectedItems", BindingFlags.NonPublic | BindingFlags.Instance));
endUpdateSelectedItems = (Action<MultiSelector>)Delegate.CreateDelegate(typeof(Action<MultiSelector>), typeof(MultiSelector).GetMethod("EndUpdateSelectedItems", BindingFlags.NonPublic | BindingFlags.Instance));
}
catch
{
beginUpdateSelectedItems = endUpdateSelectedItems = null;
}
}
private static IResetter GetResetter(Type listType)
{
try
{
MethodInfo genericReset = null, nonGenericReset = null;
Type genericResetItemType = null;
foreach (var method in listType.GetMethods(BindingFlags.Public | BindingFlags.NonPublic | BindingFlags.Instance))
{
if (method.Name != "Reset")
continue;
if (method.ReturnType != typeof(void))
continue;
var parameters = method.GetParameters();
if (parameters.Length != 1)
continue;
var parameterType = parameters[0].ParameterType;
if (parameterType.IsGenericType && parameterType.GetGenericTypeDefinition() == typeof(IEnumerable<>))
{
genericResetItemType = parameterType.GetGenericArguments()[0];
genericReset = method;
break;
}
else if (parameterType == typeof(IEnumerable))
nonGenericReset = method;
}
if (genericReset != null)
return (IResetter)Activator.CreateInstance(typeof(GenericResetter<,>).MakeGenericType(genericReset.DeclaringType, genericResetItemType), genericReset);
else if (nonGenericReset != null)
return (IResetter)Activator.CreateInstance(typeof(NonGenericResetter<>).MakeGenericType(nonGenericReset.DeclaringType), nonGenericReset);
else
return null;
}
catch
{
return null;
}
}
private interface IResetter
{
void Reset(IList list, IEnumerable items);
}
private sealed class NonGenericResetter<TTarget> : IResetter
{
private readonly Action<TTarget, IEnumerable> reset;
public NonGenericResetter(MethodInfo method)
{
this.reset = (Action<TTarget, IEnumerable>)Delegate.CreateDelegate(typeof(Action<TTarget, IEnumerable>), method);
}
public void Reset(IList list, IEnumerable items)
{
this.reset((TTarget)list, items);
}
}
private sealed class GenericResetter<TTarget, T> : IResetter
{
private readonly Action<TTarget, IEnumerable<T>> reset;
public GenericResetter(MethodInfo method)
{
this.reset = (Action<TTarget, IEnumerable<T>>)Delegate.CreateDelegate(typeof(Action<TTarget, IEnumerable<T>>), method);
}
public void Reset(IList list, IEnumerable items)
{
this.reset((TTarget)list, items.Cast<T>());
}
}
}
}
}