Hi I have a Drag and Drop which can range from a RadGridView to a RadTreeView. I wish I could do the drag and drop but that the dragged item is not displayed in the RadTreeView, is hidden. This is the code I'm using:
c#
public Page()
{
InitializeComponent();
this.GridView_ContentPlans.ItemsSource = DataGridView.GetContentPlans();
this.GridView_ContentPlans.DataLoaded += new EventHandler<EventArgs>(GridView_ContentPlans_DataLoaded);
LoadTreeFolders();
RadDragAndDropManager.AddDragQueryHandler(GridView_ContentPlans, OnDragQuery);
RadDragAndDropManager.AddDragInfoHandler(GridView_ContentPlans, OnDragInfo);
TreeView_ContentPlans.AddHandler(
RadDragAndDropManager.DropInfoEvent, new EventHandler<DragDropEventArgs>(OnDropInfo));
}
private
void OnDragQuery(object sender, DragDropQueryEventArgs e)
{
if (e.Options.Status == DragStatus.DragQuery)
{
e.QueryResult =
true;
var dataGrid = sender as RadGridView;
var items = GridView_ContentPlans.SelectedItems.Cast<ContentPlans>().ToList();
e.Options.Payload = items;
var dragCue = new TreeViewDragCue();
dragCue.ItemsSource = items;
dragCue.ItemTemplate =
this.Resources[""] as DataTemplate;
e.Options.DragCue = dragCue;
}
if (e.Options.Status == DragStatus.DropSourceQuery)
{
e.QueryResult =
true;
e.Handled =
true;
}
}
private
void OnDragInfo(object sender, DragDropEventArgs e)
{
RadGridView gridView = sender as RadGridView;
IEnumerable draggedItems = e.Options.Payload as IEnumerable;
if (e.Options.Status == DragStatus.DragInProgress)
{
TreeViewDragCue cue = new TreeViewDragCue();
cue.ItemTemplate =
this.Resources[""] as DataTemplate;
cue.ItemsSource = draggedItems;
e.Options.DragCue = cue;
}
else if (e.Options.Status == DragStatus.DragComplete)
{
IList source = gridView.ItemsSource as IList;
foreach (object draggedItem in draggedItems)
{
source.Remove(draggedItem);
}
}
}
private
void LoadTreeFolders()
{
TreeViewFolder parentFolder1 = new TreeViewFolder();
parentFolder1.Id =
"1";
parentFolder1.Name =
"Content Plan Group 1";
parentFolder1.CanCotnainEmployees =
true;
TreeViewFolder child1 = new TreeViewFolder();
child1.Id =
"11";
child1.Name =
"Sub Group 1.1";
parentFolder1.Children.Add(child1);
child1.CanCotnainEmployees =
true;
TreeViewFolder child11 = new TreeViewFolder();
child11.Id =
"111";
child11.Name =
"Sub Sub Group 1.1.1";
child1.Children.Add(child11);
child11.CanCotnainEmployees =
true;
TreeViewFolder parentFolder2 = new TreeViewFolder();
parentFolder2.Id =
"2";
parentFolder2.Name =
"Content Plan Group 2";
parentFolder2.CanCotnainEmployees =
true;
TreeViewFolder child2 = new TreeViewFolder();
child2.Id =
"21";
child2.Name =
"Sub Group 2.1";
parentFolder2.Children.Add(child2);
child2.CanCotnainEmployees =
true;
TreeViewFolder parentFolder3 = new TreeViewFolder();
parentFolder3.Id =
"3";
parentFolder3.Name =
"Content Plan Group 3";
parentFolder3.CanCotnainEmployees =
true;
folders.Add(parentFolder1);
folders.Add(parentFolder2);
folders.Add(parentFolder3);
this.TreeView_ContentPlans.ItemsSource = folders;
}
public
class ContentPlans
{
public string Name { get; set; }
public string Size { get; set; }
public int Panels { get; set; }
public string Description { get; set; }
private string _id;
public string id
{
get { return _id; }
set { _id = value; }
}
}
XAML
<
telerik1:RadTreeView Margin="0,0,0,0"
x:Name="TreeView_ContentPlans"
Width="300"
SelectionMode="Single"
VerticalAlignment="Top"
Grid.Column="0"
Foreground="#FFFFFF"
Background="Black"
FontSize="13.333"
FontFamily="Arial"
IsExpandOnDblClickEnabled="True"
IsDragTooltipEnabled="False"
IsDragDropEnabled="True"
telerik1:RadDragAndDropManager.AllowDrag="True"
telerik1:TextSearch.TextPath="Id"
telerik1:RadDragAndDropManager.AllowDrop="True"
ItemContainerStyle="{StaticResource RadTreeViewItemStyle1}"
PreviewDragEnded="TreeView_MediaFiles_PreviewDragEnded"
Selected="RadTreeViewItem_Selected"
>
<telerik1:RadTreeView.ItemTemplate >
<telerik1:HierarchicalDataTemplate ItemsSource="{Binding Children}" >
<TextBlock Text="{Binding Name}" />
</telerik1:HierarchicalDataTemplate>
</telerik1:RadTreeView.ItemTemplate>
</telerik1:RadTreeView>
<
telerik1:RadGridView Margin="0,3,0,0"
Grid.Column="1"
VerticalAlignment="Top"
x:Name="GridView_ContentPlans"
AlternateRowBackground="#FF262626"
Background="#FF262626"
BorderBrush="{x:Null}"
ColumnBackground="#FF262626"
Foreground="White"
HorizontalGridLinesBrush="#FF8B8B8B"
VerticalGridLinesBrush="{x:Null}"
BorderThickness="0"
GridLinesVisibility="Horizontal"
ShowGroupPanel="False"
HorizontalAlignment="Left"
Width="800"
Height="194"
GroupPanelBackground="{x:Null}"
FontSize="13.333"
CanUserFreezeColumns="True"
telerik1:RadDragAndDropManager.AllowDrag="True"
>
Thanks
3 Answers, 1 is accepted
First of all, please accept our apologies for the late response.
We prepared a sample project for you that implements the desired behavior. Please examine it and let us know if it works for you. It seems that when you remove the dragged items from the RadGridView (in the OnDragInfo event handler) the payload is also cleared. Therefore, since the built-in drop operations implemented in the RadTreeView control depend on the e.Options.Payload to add the dragged items in the RadTreeView Items collection, no items are really dropped.
Therefore it would be better to remove the dragged items from the GridView Items collection after the drop in the tree is completed - you can use the RadTreeView.DragEnded event. Another approach is to add the dragged items in the tree manually, handling the DropInfo event of the RadTreeView.
Feel free to ask if you need further assistance.
Greetings,
Petar Mladenov
the Telerik team
Rank 1
I am not sure if I understand you requirement correctly - do you want to add the dragged node into the RadTreeView collection but not display it? If this is the case, in a databound TreeView, you can define its ItemsSource collection as a collection that don't implement the INotifyCollectionChnaged interface. This way the RadTreeView control won't be aware of the changes made to its underlying collection and even when you add new items to it (by dragging from the RadGridView) they won't be displayed in the control. Such collection is the List collection.
If, however, you want to drag an item from the RadGridView onto the RadTreeView without affecting the RadTreeView source collection at all, you can remove the RadTreeView DragEnded() event and handle the PreviewDragEnded() event instead:
private void myTreeView_PreviewDragEnded(object sender, RadTreeViewDragEndedEventArgs e){ e.Handled = true; IList source = myGridView.ItemsSource as IList; foreach (object draggedItem in e.DraggedItems) { source.Remove(draggedItem); }}I hope this info helps.
Regards,
Tina Stancheva
the Telerik team