ASP.NET MVC Controls | ComponentOne
Working with Controls / TreeView / Work with TreeView / Drag and Drop
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    Drag and Drop
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    The TreeView control supports drag and drop operations within the same treeview and among multiple treeviews. To perform drag and drop operation in TreeView nodes, you need to set the AllowDragging property of TreeView to true.

    When drag and drop operations are enabled in TreeView, users may drag any node to any position within the tree. You can customize this behavior by handling the TreeView drag and drop events:

    In this example, we will use OnClientDragStart and OnClientDragOver to provide customized drag and drop operations on a TreeView control. We are using OnClientDragStart event to allow users to drag parent nodes and OnClientDragOver event to allow users to drop into empty nodes.

    In the code example below, we are using OnClientDragStart() method that raises the dragStart event. In the dragStart(treeview, e) function, treeview is the sender, and e is a type of TreeNodeEventArgs class. Similarly, OnClientDragOver() method raises the dragOver event. In the dragOver(treeview, e) function, treeview is the sender, and e is a type of TreeNodeEventArgs class.

    The below example code uses Property model added in the QuickStart section.

    Copy Code
    @using <ApplicationName.Models>
    @model Property[]
    <script type="text/javascript">
            var allowDraggingParentNodes = true;
            var allowDroppingIntoEmpty = true;
            // use OnClientDragStart event to honor the allowDraggingParentNodes setting
            // by setting the 'cancel' event parameter to true
            function dragStart(treeview, e) {
                if (e.node.hasChildren) {
                    if (!allowDraggingParentNodes) {
                        e.cancel = true; // prevent dragging parent nodes
                    } else {
                        e.node.isCollapsed = true; // collapse parent nodes when dragging
            // use OnClientDragOver event to honor the allowDroppingIntoEmpty setting
            // by changing the 'position' event parameter to 'Before'
            function dragOver(treeview, e) {
                if (!allowDroppingIntoEmpty &&
                    !e.dropTarget.hasChildren &&
                     e.position == wijmo.nav.DropPosition.Into) {
                    e.position = wijmo.nav.DropPosition.Before;