4

我在我的应用程序中使用 Telerik RadGridView,它有一个 GridViewSelectColumn 项目,它允许我选择网格中的各种项目。我有一个操作此选择的按钮,但不确定如何获取所选项目的列表。问题是我在 Caliburn.Micro 中使用了 MVVM 模式。是否需要在视图中找到控件并遍历选中项列表?对于一个简单的任务来说,这似乎需要做很多工作。我会很感激任何想法。

4

5 回答 5

11

Telerik 的 RadGridView 的问题在于,它的 SelectedItem 集合是只读的,因此您不能将双向绑定到 SelectedItems。

解决方法是使用自定义行为在 RadGridView 和您的 ViewModels SelectedItem 集合之间进行同步

您可以使用此行为:

// Behavior for synchronizing a RadDataGrid's SelectedItems collection with a SelectedItems collection of the ViewModel (the Network)
// The problem is, that RadDataGrid.SelectedItems is a read-only collection and therefore cannot be used for two-way binding.

class SelectedSyncBehavior
    : Behavior<RadGridView>
{
    bool _collectionChangedSuspended = false;

    protected override void OnAttached()
    {
        base.OnAttached();
        AssociatedObject.SelectedItems.CollectionChanged += GridSelectedItems_CollectionChanged;
    }

    /// <summary>
    /// Getter/Setter for DependencyProperty, bound to the DataContext's SelectedItems ObservableCollection
    /// </summary>
    public INotifyCollectionChanged SelectedItems
    {
        get { return (INotifyCollectionChanged)GetValue(SelectedItemsProperty); }
        set { SetValue(SelectedItemsProperty, value); }
    }

    /// <summary>
    /// Dependency Property "SelectedItems" is target of binding to DataContext's SelectedItems
    /// </summary>
    public static readonly DependencyProperty SelectedItemsProperty =
        DependencyProperty.Register("SelectedItems", typeof(INotifyCollectionChanged), typeof(SelectedSyncBehavior), new PropertyMetadata(OnSelectedItemsPropertyChanged));

    /// <summary>
    /// PropertyChanged handler for DependencyProperty "SelectedItems"
    /// </summary>
    private static void OnSelectedItemsPropertyChanged(DependencyObject target, DependencyPropertyChangedEventArgs args)
    {
        INotifyCollectionChanged collection = args.NewValue as INotifyCollectionChanged;
        if (collection != null)
        {
            // Hook to the Network's SelectedItems
            collection.CollectionChanged += (target as SelectedSyncBehavior).ContextSelectedItems_CollectionChanged;
        }
    }

    /// <summary>
    /// Will be called, when the Network's SelectedItems collection changes
    /// </summary>
    void ContextSelectedItems_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        if (_collectionChangedSuspended) return;    // Don't react recursively to CollectionChanged events

        _collectionChangedSuspended = true;

        // Select and unselect items in the grid
        if (e.NewItems != null)
            foreach (object item in e.NewItems)
                AssociatedObject.SelectedItems.Add(item);

        if (e.OldItems != null)
            foreach (object item in e.OldItems)
                AssociatedObject.SelectedItems.Remove(item);

        _collectionChangedSuspended = false;
    }

    /// <summary>
    /// Will be called when the GridView's SelectedItems collection changes
    /// </summary>
    void GridSelectedItems_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        if (_collectionChangedSuspended) return;    // Don't react recursively to CollectionChanged events

        _collectionChangedSuspended = true;

        // Select and unselect items in the DataContext
        if (e.NewItems != null)
            foreach (object item in e.NewItems)
                (SelectedItems as IList).Add(item);

        if (e.OldItems != null)
            foreach (object item in e.OldItems)
                (SelectedItems as IList).Remove(item);

        _collectionChangedSuspended = false;
    }

}

将此行为与 RadGridViews 一起使用,如下所示:

<i:Interaction.Behaviors>
   <behaviors:SelectedSyncBehavior SelectedItems="{Binding ViewModel.SelectedItems}" />
</i:Interaction.Behaviors>
于 2014-02-25T15:37:51.220 回答
2

将 bool IsSelected 添加到集合中的项目:

 public class Customer
    {
        public int Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public bool IsSelected { get; set; }
    }

 private BindableCollection<Customer> _customers;
        public BindableCollection<Customer> Customers
        {
            get { return _customers; }
            set
            {
                _customers = value;
                NotifyOfPropertyChange(() => Customers);
            }
        }

示例代码 - bitbucket

下载

于 2011-06-30T14:37:34.010 回答
0

这是上面答案的清理版本。这将删除下划线、添加限定符、访问器、大括号等。

public class SelectedItemsBehavior : Behavior<RadGridView>
{
    private bool collectionChangedSuspended;

    /// <summary>
    /// Called after the behavior is attached to an AssociatedObject.
    /// </summary>
    /// <remarks>
    /// Override this to hook up functionality to the AssociatedObject.
    /// </remarks>
    protected override void OnAttached()
    {
        base.OnAttached();
        this.AssociatedObject.SelectedItems.CollectionChanged += this.GridSelectedItemsCollectionChanged;
    }

    /// <summary>
    /// Getter/Setter for DependencyProperty, bound to the DataContext's SelectedItems ObservableCollection
    /// </summary>
    public INotifyCollectionChanged SelectedItems
    {
        get => (INotifyCollectionChanged)this.GetValue(SelectedItemsProperty);
        set => this.SetValue(SelectedItemsProperty, value);
    }

    /// <summary>
    /// Dependency Property "SelectedItems" is target of binding to DataContext's SelectedItems
    /// </summary>
    public static readonly DependencyProperty SelectedItemsProperty =
        DependencyProperty.Register("SelectedItems", typeof(INotifyCollectionChanged), typeof(SelectedItemsBehavior), new PropertyMetadata(OnSelectedItemsPropertyChanged));

    /// <summary>
    /// PropertyChanged handler for DependencyProperty "SelectedItems"
    /// </summary>
    private static void OnSelectedItemsPropertyChanged(DependencyObject target, DependencyPropertyChangedEventArgs args)
    {
        INotifyCollectionChanged collection = args.NewValue as INotifyCollectionChanged;
        if (collection != null)
        {
            collection.CollectionChanged += ((SelectedItemsBehavior)target).ContextSelectedItemsCollectionChanged;
        }
    }

    /// <summary>
    /// Will be called, when the Network's SelectedItems collection changes
    /// </summary>
    private void ContextSelectedItemsCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        if (this.collectionChangedSuspended)
        {
            return; 
        }

        this.collectionChangedSuspended = true;

        if (e.NewItems != null)
        {
            foreach (object item in e.NewItems)
            {
                this.AssociatedObject.SelectedItems.Add(item);
            }
        }

        if (e.OldItems != null)
        {
            foreach (object item in e.OldItems)
            {
                this.AssociatedObject.SelectedItems.Remove(item);
            }
        }

        this.collectionChangedSuspended = false;
    }

    /// <summary>
    /// Will be called when the GridView's SelectedItems collection changes
    /// </summary>
    private void GridSelectedItemsCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        if (this.collectionChangedSuspended)
        {
            return;
        }

        this.collectionChangedSuspended = true;

        if (e.NewItems != null)
        {
            foreach (object item in e.NewItems)
            {
                ((IList)this.SelectedItems).Add(item);
            }
        }

        if (e.OldItems != null)
        {
            foreach (object item in e.OldItems)
            {
                ((IList)this.SelectedItems).Remove(item);
            }
        }

        this.collectionChangedSuspended = false;
    }
}
于 2017-12-13T19:04:04.710 回答
0

这是@Knasterbax 类的清理副本,其中包含显式私有修饰符和空传播:

// Behavior for synchronizing Telerik RadDataGrid's SelectedItems collection 
//  with a SelectedItems collection of the ViewModel.   
public class SelectedSyncBehavior : Behavior<RadGridView>
{
    private bool collectionChangedSuspended;
    public static readonly DependencyProperty SelectedItemsProperty = DependencyProperty.Register("SelectedItems",
        typeof(INotifyCollectionChanged), typeof(SelectedSyncBehavior), new PropertyMetadata(OnSelectedItemsPropertyChanged));

    protected override void OnAttached()
    {
        base.OnAttached();
        AssociatedObject.SelectedItems.CollectionChanged += GridSelectedItems_CollectionChanged;
    }

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

    private static void OnSelectedItemsPropertyChanged(DependencyObject target, DependencyPropertyChangedEventArgs args)
    {
        var collection = args.NewValue as INotifyCollectionChanged;
        if (collection == null) return;
        var selectedSyncBehavior = target as SelectedSyncBehavior;
        if (selectedSyncBehavior != null) collection.CollectionChanged += selectedSyncBehavior.ContextSelectedItems_CollectionChanged;
    }

    private void ContextSelectedItems_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        if (collectionChangedSuspended) return;    // Don't react recursively to CollectionChanged events

        collectionChangedSuspended = true;

        if (e.NewItems != null)
            foreach (var item in e.NewItems)
                AssociatedObject.SelectedItems.Add(item);

        if (e.OldItems != null)
            foreach (var item in e.OldItems)
                AssociatedObject.SelectedItems.Remove(item);

        collectionChangedSuspended = false;
    }

    private void GridSelectedItems_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        if (collectionChangedSuspended) return;    // Don't react recursively to CollectionChanged events

        collectionChangedSuspended = true;

        if (e.NewItems != null)
            foreach (var item in e.NewItems)
            {
                var list = SelectedItems as IList;
                list?.Add(item);
            }

        if (e.OldItems != null)
            foreach (var item in e.OldItems)
            {
                var list = SelectedItems as IList;
                list?.Remove(item);
            }

        collectionChangedSuspended = false;
    }

}
于 2017-10-17T22:04:25.633 回答
-1

在某些情况下,您无法添加布尔值(例如 ObseravbleCollection。

请看一下这个解决方案。

于 2012-10-28T09:13:29.713 回答