Drag and drop
28 Sep 202014 minutes to read
To perform drag and drop operation in TreeView specify “AllowDragAndDrop” as true. It allows you to drag and drop node in all level of same TreeView.
<ej:TreeView
ID="treeView"
runat="server"
DataTextField="Text"
DataIdField="Id"
DataParentIdField="Parent"
DataExpandedField="Expanded"
AllowDragAndDrop="true">
</ej:TreeView>NOTE
TreeView provides much easier option to drop the dragged nodes at any levels by indicator lines with icons.
Position Indicators
TreeView provides much easier option to drop the dragged nodes at any levels by indicator lines with icons such as line, plus/ minus and restrict icons while dragging and dropping the nodes. It represents exact position where the node to be dropped as sibling or child.
|
Indicators |
description |
| Plus icon | represents the dragged node to be added as child of targeted node |
| Minus with restrict icon | represents the dragged node not to be dropped at the hovered region |
| In between icon | represents the dragged node to be dropped in between the nodes as siblings |
Restriction
You can restrict the dragged nodes to be dropped at siblings or children’s level by using “AllowDropSibling” and ’‘AllowDropChild’ property.
<ej:TreeView
ID="treeView"
runat="server"
DataTextField="Text"
DataIdField="Id"
DataParentIdField="Parent"
DataExpandedField="Expanded"
AllowDragAndDrop="true"
AllowDropSibling="true"
AllowDropChild="false">
</ej:TreeView>Drag and drop between Trees
You can drag and drop tree nodes between two TreeView by setting “AllowDragAndDrop” as true along with “AllowDragAndDropAcrossControl” as true.
The nodeDrag, nodeDragStart, nodeDragStop and
nodeDropped event occurs based on Treeview node drag and drop state.
In the code behind page, create a data list which contains the details about tree nodes and map the list data to DataSource property of TreeView.
public partial class TreeViewFeatures : System.Web.UI.Page
{
List<LoadData> treeData1 = new List<LoadData>();
List<LoadData> treeData2 = new List<LoadData>();
protected void Page_Load(object sender, EventArgs e)
{
treeData1.Add(new LoadData { Id = 1, Parent = 0, Text = "Item 1", Expanded = true });
treeData1.Add(new LoadData { Id = 2, Parent = 0, Text = "Item 2" });
treeData1.Add(new LoadData { Id = 3, Parent = 0, Text = "Item 3" });
treeData1.Add(new LoadData { Id = 4, Parent = 0, Text = "Item 4" });
treeData1.Add(new LoadData { Id = 5, Parent = 1, Text = "Item 1.1" });
treeData1.Add(new LoadData { Id = 6, Parent = 1, Text = "Item 1.2" });
treeData1.Add(new LoadData { Id = 7, Parent = 1, Text = "Item 1.3" });
treeData1.Add(new LoadData { Id = 8, Parent = 3, Text = "Item 3.1" });
treeData1.Add(new LoadData { Id = 9, Parent = 3, Text = "Item 3.2" });
treeData1.Add(new LoadData { Id = 10, Parent = 5, Text = "Item 1.1.1" });
this.treeViewDrag.DataSource = treeData1;
treeData2.Add(new LoadData { Id = 11, Parent = 0, Text = "Item 5", Expanded = true });
treeData2.Add(new LoadData { Id = 12, Parent = 0, Text = "Item 6" });
treeData2.Add(new LoadData { Id = 13, Parent = 0, Text = "Item 7" });
treeData2.Add(new LoadData { Id = 14, Parent = 0, Text = "Item 4" });
treeData2.Add(new LoadData { Id = 15, Parent = 11, Text = "Item 5.1" });
treeData2.Add(new LoadData { Id = 16, Parent = 11, Text = "Item 5.2" });
treeData2.Add(new LoadData { Id = 17, Parent = 11, Text = "Item 5.3" });
treeData2.Add(new LoadData { Id = 18, Parent = 13, Text = "Item 7.1" });
treeData2.Add(new LoadData { Id = 19, Parent = 13, Text = "Item 7.2" });
treeData2.Add(new LoadData { Id = 10, Parent = 15, Text = "Item 5.1.1" });
this.treeViewDrop.DataSource = treeData2;
}
}
public class LoadData
{
public int Id { get; set; }
public int Parent { get; set; }
public string Text { get; set; }
public bool Expanded { get; set; }
}In the view page, add TreeView element and map the properties defined in to the corresponding fields in data source with that specify the drag and drop settings.
<div style="float: left; width: 200px;">
<ej:TreeView
ID="treeViewDrag"
runat="server"
DataTextField="Text"
DataIdField="Id"
DataParentIdField="Parent"
DataExpandedField="Expanded"
AllowDragAndDrop="true"
AllowDropChild="true"
AllowDropSibling="true"
AllowDragAndDropAcrossControl="true">
</ej:TreeView>
</div>
<div style="float: left; width: 200px;">
<ej:TreeView
ID="treeViewDrop"
runat="server"
DataTextField="Text"
DataIdField="Id"
DataParentIdField="Parent"
DataExpandedField="Expanded"
AllowDragAndDrop="true"
AllowDropChild="true"
AllowDropSibling="true"
AllowDragAndDropAcrossControl="true">
</ej:TreeView>
</div>Auto node structuring
You may not need to have two TreeView to be in same structured node while drag and drop the nodes between them. But after the node has been dropped, it should get structure of the TreeView node in which dropped. By default TreeView auto structure the node whenever you drop a node from different tree.
<div style="float: left; width: 200px;">
<ej:TreeView
ID="treeViewDrag"
runat="server"
DataTextField="Text"
DataIdField="Id"
DataParentIdField="Parent"
DataExpandedField="Expanded"
AllowDragAndDrop="true"
AllowDropChild="true"
AllowDropSibling="true"
AllowDragAndDropAcrossControl="true"
ShowCheckbox="true">
</ej:TreeView>
</div>
<div style="float: left; width: 200px;">
<ej:TreeView
ID="treeViewDrop"
runat="server"
DataTextField="Text"
DataIdField="Id"
DataParentIdField="Parent"
DataExpandedField="Expanded"
AllowDragAndDrop="true"
AllowDropChild="true"
AllowDropSibling="true"
AllowDragAndDropAcrossControl="true">
</ej:TreeView>
</div>NOTE
Auto node structure only applicable for well-structured node object.