Question

如何从MVVM WPF项目中的DataGrid中选择多个项目？

Answer 1

您只需添加自定义依赖项属性即可：

public class CustomDataGrid : DataGrid
{
    public CustomDataGrid ()
    {
        this.SelectionChanged += CustomDataGrid_SelectionChanged;
    }

    void CustomDataGrid_SelectionChanged (object sender, SelectionChangedEventArgs e)
    {
        this.SelectedItemsList = this.SelectedItems;
    }
    #region SelectedItemsList

    public IList SelectedItemsList
    {
        get { return (IList)GetValue (SelectedItemsListProperty); }
        set { SetValue (SelectedItemsListProperty, value); }
    }

    public static readonly DependencyProperty SelectedItemsListProperty =
            DependencyProperty.Register ("SelectedItemsList", typeof (IList), typeof (CustomDataGrid), new PropertyMetadata (null));

    #endregion
}

现在您可以在XAML中使用此dataGrid：

<Window x:Class="DataGridTesting.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
    xmlns:local="clr-namespace:DataGridTesting.CustomDatagrid"
    Title="MainWindow"
    Height="350"
    Width="525">
  <DockPanel>
    <local:CustomDataGrid ItemsSource="{Binding Model}"
        SelectionMode="Extended"
        AlternatingRowBackground="Aquamarine"
        SelectionUnit="FullRow"
        IsReadOnly="True"
        SnapsToDevicePixels="True"
        SelectedItemsList="{Binding TestSelected, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"/>
  </DockPanel>
</Window>

我的ViewModel：

public class MyViewModel : INotifyPropertyChanged
{
    private static object _lock = new object ();
    private List<MyModel> _myModel;

    public IEnumerable<MyModel> Model { get { return _myModel; } }

    private IList _selectedModels = new ArrayList ();

    public IList TestSelected
    {
        get { return _selectedModels; }
        set
        {
            _selectedModels = value;
            RaisePropertyChanged ("TestSelected");
        }
    }

    public MyViewModel ()
    {
        _myModel = new List<MyModel> ();
        BindingOperations.EnableCollectionSynchronization (_myModel, _lock);

        for (int i = 0; i < 10; i++)
        {
            _myModel.Add (new MyModel
            {
                Name = "Test " + i,
                Age = i * 22
            });
        }
        RaisePropertyChanged ("Model");
    }

    public event PropertyChangedEventHandler PropertyChanged;

    public void RaisePropertyChanged (string propertyName)
    {
        var pc = PropertyChanged;
        if (pc != null)
            pc (this, new PropertyChangedEventArgs (propertyName));
    }
}

我的模特：

public class MyModel
{
    public string Name { get; set; }
    public int Age { get; set; }
}

最后，这是MainWindow：

背后的代码

public partial class MainWindow : Window
{
    public MainWindow ()
    {
        InitializeComponent ();
        this.DataContext = new MyViewModel ();
    }
}

我希望这种干净的MVVM设计有所帮助。

Answer 2

我要做的是使用Behaviors创建System.Windows.Interactivity。您必须在项目中手动引用它。

给定一个不公开SelectedItems的控件，例如（ListBox，DataGrid）

您可以创建类似这样的行为类

public class ListBoxSelectedItemsBehavior : Behavior<ListBox>
{
    protected override void OnAttached()
    {
        AssociatedObject.SelectionChanged += AssociatedObjectSelectionChanged;
    }

    protected override void OnDetaching()
    {
        AssociatedObject.SelectionChanged -= AssociatedObjectSelectionChanged;
    }

    void AssociatedObjectSelectionChanged(object sender, SelectionChangedEventArgs e)
    {
        var array = new object[AssociatedObject.SelectedItems.Count];
        AssociatedObject.SelectedItems.CopyTo(array, 0);
        SelectedItems = array;
    }

    public static readonly DependencyProperty SelectedItemsProperty =
        DependencyProperty.Register("SelectedItems", typeof(IEnumerable), typeof(ListBoxSelectedItemsBehavior), 
        new FrameworkPropertyMetadata(null, FrameworkPropertyMetadataOptions.BindsTwoWayByDefault));

    public IEnumerable SelectedItems
    {
        get { return (IEnumerable)GetValue(SelectedItemsProperty); }
        set { SetValue(SelectedItemsProperty, value); }
    }
}

在XAML Binding我会i这样xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity" behaviors而Behavior是<ListBox> <i:Interaction.Behaviors> <behaviors:ListBoxSelectedItemsBehavior SelectedItems="{Binding SelectedItems, Mode=OneWayToSource}" /> </i:Interaction.Behaviors>的命名空间类

DataContext

假设ListBox的{{1}}在SelectedItems中有ViewModel属性，则会自动更新SelectedItems。你已经封装了从event订阅的View，即

<ListBox SelectionChanged="ListBox_SelectionChanged"/>

如果需要，您可以将Behavior类更改为DataGrid类型。

Answer 3

我在我的应用中使用此解决方案：

XAML：

<i:Interaction.Triggers>
     <i:EventTrigger EventName="SelectionChanged">
         <i:InvokeCommandAction Command="{Binding SelectItemsCommand}" CommandParameter="{Binding Path=SelectedItems,ElementName=TestListView}"/>
     </i:EventTrigger>
</i:Interaction.Triggers>

在xaml文件的顶部，添加以下代码行：

xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"

SelectedItemsCommand是ICommand类型，它在您的viewmodel中写入。

使用过的DLL：

System.Windows.Interactivity.dll

Answer 4

使用WPF的默认DataGrid，无法使用绑定，因为SelectedItem - 属性可能导致SelectedItems - 属性不是DependencyProperty。

获得所需内容的一种方法是注册DataGrid的SelectionChanged - 事件，以更新存储所选项目的ViewModel的属性。

DataGrid的属性SelectedItems属于IList类型，因此您需要将列表中的项目强制转换为您的特定类型。

C＃

public MyViewModel {
  get{
    return this.DataContext as MyViewModel;
  }
}

private void DataGrid_SelectionChanged(object sender, SelectionChangedEventArgs e) {
  // ... Get SelectedItems from DataGrid.
  var grid = sender as DataGrid;
  var selected = grid.SelectedItems;

  List<MyObject> selectedObjects = selected.OfType<MyObject>().ToList();

  MyViewModel.SelectedMyObjects = selectedObjects;
}

XAML

<Window x:Class="WpfApplication1.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
    <Grid>
    <DataGrid
        SelectionChanged="DataGrid_SelectionChanged"
        />
    </Grid>
</Window>

Answer 5

您可以在模型中添加“IsSelected”属性，并在行中添加一个复选框。

Answer 6

您可以使用可重用的通用基类。这样，您就可以从代码和UI 中选择行。

这是我希望可以选择的示例类

public class SelectableItem<T> : System.ComponentModel.INotifyPropertyChanged { public SelectableItem(T item) { Item = item; } public T Item { get; set; } bool _isSelected; public bool IsSelected { get { return _isSelected; } set { if (value == _isSelected) { return; } _isSelected = value; if (PropertyChanged != null) { PropertyChanged(this, new System.ComponentModel.PropertyChangedEventArgs("IsSelected")); } } } public event System.ComponentModel.PropertyChangedEventHandler PropertyChanged; }

为可选类创建通用基类。设置IsSelected时，INotifyPropertyChanged会更新UI。

public class MySelectableItem: SelectableItem<MyClass> { public MySelectableItem(MyClass item) :base(item) { } }

创建可选择的类

ObservableCollection<MySelectableItem> MyObservableCollection ...

创建要绑定到
的属性
MyObservableCollection = myItems.Select(x => new MySelectableItem(x));

设置比赛

<DataGrid ItemsSource="{Binding MyObservableCollection}" SelectionMode="Extended"> <DataGrid.Resources> <Style TargetType="DataGridRow"> <Setter Property="IsSelected" Value="{Binding IsSelected}" /> </Style> </DataGrid.Resources> </DataGrid>

绑定到datagrid并在DataGridRow上添加一个样式，该样式绑定到MySelectedItem上的IsSelected propety

var selectedItems = MyObservableCollection.Where(x=>x.IsSelected).Select(y=>y.Item);

获取所选行/项目

MyObservableCollection[0].IsSelected = true;

选择行/项目

if(isset($_POST['submit1'])){ //do your code for form 1 } if(isset($_POST['submit2'])){ //do your code for form 2 }

编辑---＆GT; 当EnableRowVirtualization为真时，它似乎不起作用

Answer 7

WPF DataGrid允许这样做。只需将DataGrid.Rows.SelectionMode和DataGrid.Rows.SelectionUnit设置为＆＃34; Extended＆＃34;和＆＃34; CellOrRowHeader＆＃34;分别。这可以在Blend中完成，如我所包含的图像所示。这将允许用户使用shift或ctrl键继续选择，根据需要选择每个单元格，整行等。 enter image description here

Answer 8

我正在处理的项目使用MVVM Light，我发现this blog post是最简单的解决方案。我在这里重复解决方案：

查看型号：

  add() {
    this.data.item.push({ title: 'pushed', config: { sizex: 1} });
  }

XAML：

using GalaSoft.MvvmLight;
using GalaSoft.MvvmLight.Command;
...

public class SomeVm : ViewModelBase {

    public SomeVm() {
        SelectItemsCommand = new RelayCommand<IList>((items) => {
            Selected.Clear();
            foreach (var item in items) Selected.Add((SomeClass)item);
        });

        ViewCommand = new RelayCommand(() => {
            foreach (var selected in Selected) {
                // todo do something with selected items
            }
        });
    }

    public List<SomeClass> Selected { get; set; }
    public RelayCommand<IList> SelectionChangedCommand { get; set; }
    public RelayCommand ViewCommand { get; set; }
}

从MVVM WPF项目中的DataGrid中选择多个项目

8 个答案: