# Drag and Drop Using RadDragDropService

This article will guide you through the process of achieving drag and drop functionality from **RadScheduler** to **RadGridView** and vice versa. For this purpose, we will use the **RadDragDropService**, supported by both of the controls.

Let’s assume that our **RadScheduler** is in unbound mode and the **RadGridView** control is bound to *Appointments* data table.

## Drag and Drop from RadGridView to RadScheduler

1. The first thing we need to do is to start the **RadGridView**’s drag and drop service when a user clicks on a row with the left mouse down. For this purpose we should create a custom [grid behavior](https://www.telerik.com/products/winforms/documentation/controls/gridview/visual-elements/rows/row-behaviors):

```C#
//initiates drag and drop service for clicked rows
public class CustomRowGridBehavior : GridDataRowBehavior
{
    protected override bool OnMouseDownLeft(MouseEventArgs e)
    {
        GridDataRowElement row = this.GetRowAtPoint(e.Location) as GridDataRowElement;
        if (row != null)
        {
            RadGridViewDragDropService svc = this.GridViewElement.GetService<RadGridViewDragDropService>();
            svc.Start(row);
        }
        return base.OnMouseDownLeft(e);
    }
}

```

```VB.NET
'initiates drag and drop service for clicked rows
Public Class CustomRowGridBehavior
Inherits GridDataRowBehavior
    Protected Overrides Function OnMouseDownLeft(e As MouseEventArgs) As Boolean
        Dim row As GridDataRowElement = TryCast(Me.GetRowAtPoint(e.Location), GridDataRowElement)
        If row IsNot Nothing Then
            Dim svc As RadGridViewDragDropService = Me.GridViewElement.GetService(Of RadGridViewDragDropService)()
            svc.Start(row)
        End If
        Return MyBase.OnMouseDownLeft(e)
    End Function
End Class

```

2\. Next, we should register this behavior in our grid:

```C#
//register the custom row behavior
BaseGridBehavior gridBehavior = this.radGridView1.GridBehavior as BaseGridBehavior;
gridBehavior.UnregisterBehavior(typeof(GridViewDataRowInfo));
gridBehavior.RegisterBehavior(typeof(GridViewDataRowInfo), new CustomRowGridBehavior());

```

```VB.NET
'register the custom row behavior
Dim gridBehavior As BaseGridBehavior = TryCast(Me.RadGridView1.GridBehavior, BaseGridBehavior)
gridBehavior.UnregisterBehavior(GetType(GridViewDataRowInfo))
gridBehavior.RegisterBehavior(GetType(GridViewDataRowInfo), New CustomRowGridBehavior())
```

3\. It is necessary to subscribe to the **PreviewDragStart**, **PreviewDragOver** and **PreviewDragDrop** events of the grid’s **RadDragDropService**. The **PreviewDragStart** event is fired once the drag and drop service on the grid is started. We should notify the service that the drag and drop operation can move forward. In the **PreviewDragOver** event you can control on what targets to allow dropping the dragged row. The **PreviewDragDrop** event performs the actual move of the row from the **RadGridView** to the **RadScheduler**.

```C#
//handle drag and drop events for the grid through the DragDrop service
RadDragDropService svc = this.radGridView1.GridViewElement.GetService<RadDragDropService>();
svc.PreviewDragStart += svc_PreviewDragStart;
svc.PreviewDragDrop += svc_PreviewDragDrop;
svc.PreviewDragOver += svc_PreviewDragOver;

```

```VB.NET
'handle drag and drop events for the grid through the DragDrop service
Dim svc As RadDragDropService = Me.RadGridView1.GridViewElement.GetService(Of RadDragDropService)()
AddHandler svc.PreviewDragStart, AddressOf svc_PreviewDragStart
AddHandler svc.PreviewDragDrop, AddressOf svc_PreviewDragDrop
AddHandler svc.PreviewDragOver, AddressOf svc_PreviewDragOver

```

```C#
//required to initiate drag and drop when grid is in bound mode
private void svc_PreviewDragStart(object sender, PreviewDragStartEventArgs e)
{
    e.CanStart = true;
}

private void svc_PreviewDragOver(object sender, RadDragOverEventArgs e)
{
    if (e.DragInstance is GridDataRowElement)
    {
        e.CanDrop = e.HitTarget is SchedulerCellElement;
    }
}

private void svc_PreviewDragDrop(object sender, RadDropEventArgs e)
{
    SchedulerCellElement schedulerCell = e.HitTarget as SchedulerCellElement;
    if (schedulerCell == null)
    {
        DayViewAllDayHeader allDay = (this.radScheduler1.SchedulerElement.ViewElement as SchedulerDayViewElement).AllDayHeaderElement;
        schedulerCell = SchedulerUIHelper.GetCellAtPoint(e.DropLocation, allDay.Children);
    }
    if (schedulerCell == null)
    {
        return;
    }
    GridDataRowElement draggedRow = e.DragInstance as GridDataRowElement;
    if (draggedRow == null)
    {
        return;
    }
    
    DataRowView dataRowView = draggedRow.Data.DataBoundItem as DataRowView;
    if (dataRowView != null)
    {
        if (draggedRow.GridControl.DataSource != null && typeof(BindingSource).IsAssignableFrom(draggedRow.GridControl.DataSource.GetType()))
        {
            Appointment appointment = new Appointment();
            appointment.Start = (DateTime)draggedRow.RowInfo.Cells["Start"].Value;
            appointment.End = (DateTime)draggedRow.RowInfo.Cells["End"].Value;
            //adjust start/end according to target cell
            appointment.End = schedulerCell.Date.AddMinutes(appointment.Duration.TotalMinutes);
            appointment.Start = schedulerCell.Date;
            appointment.Summary = string.Empty + draggedRow.RowInfo.Cells["Summary"].Value;
            appointment.Description = string.Empty + draggedRow.RowInfo.Cells["Description"].Value;
            appointment.Location = string.Empty + draggedRow.RowInfo.Cells["Location"].Value;
            appointment.StatusId = (int)draggedRow.RowInfo.Cells["StatusId"].Value;
            appointment.BackgroundId = (int)draggedRow.RowInfo.Cells["BackgroundId"].Value;
            this.radScheduler1.Appointments.Add(appointment);
            
            dataRowView.Row.Table.Rows.Remove(dataRowView.Row);
        }
        else
        {
            throw new ApplicationException("Unhandled Scenario");
        }
    }
}

```

```VB.NET
'required to initiate drag and drop when grid is in bound mode
Private Sub svc_PreviewDragStart(sender As Object, e As PreviewDragStartEventArgs)
    e.CanStart = True
End Sub

Private Sub svc_PreviewDragOver(sender As Object, e As RadDragOverEventArgs)
    If TypeOf e.DragInstance Is GridDataRowElement Then
        e.CanDrop = TypeOf e.HitTarget Is SchedulerCellElement
    End If
End Sub

Private Sub svc_PreviewDragDrop(sender As Object, e As RadDropEventArgs)
    Dim schedulerCell As SchedulerCellElement = TryCast(e.HitTarget, SchedulerCellElement)
    If schedulerCell Is Nothing Then
        Dim allDay As DayViewAllDayHeader = TryCast(Me.RadScheduler1.SchedulerElement.ViewElement, SchedulerDayViewElement).AllDayHeaderElement
        schedulerCell = SchedulerUIHelper.GetCellAtPoint(e.DropLocation, allDay.Children)
    End If
    If schedulerCell Is Nothing Then
        Return
    End If
    Dim draggedRow As GridDataRowElement = TryCast(e.DragInstance, GridDataRowElement)
    If draggedRow Is Nothing Then
        Return
    End If

    Dim dataRowView As DataRowView = TryCast(draggedRow.Data.DataBoundItem, DataRowView)
    If dataRowView IsNot Nothing Then
        If draggedRow.GridControl.DataSource IsNot Nothing AndAlso GetType(BindingSource).IsAssignableFrom(draggedRow.GridControl.DataSource.[GetType]()) Then
            Dim appointment As New Appointment()
            appointment.Start = DirectCast(draggedRow.RowInfo.Cells("Start").Value, DateTime)
            appointment.[End] = DirectCast(draggedRow.RowInfo.Cells("End").Value, DateTime)
            'adjust start/end according to target cell
            appointment.[End] = schedulerCell.[Date].AddMinutes(appointment.Duration.TotalMinutes)
            appointment.Start = schedulerCell.[Date]
            appointment.Summary = String.Empty + draggedRow.RowInfo.Cells("Summary").Value
            appointment.Description = String.Empty + draggedRow.RowInfo.Cells("Description").Value
            appointment.Location = String.Empty + draggedRow.RowInfo.Cells("Location").Value
            appointment.StatusId = CInt(draggedRow.RowInfo.Cells("StatusId").Value)
            appointment.BackgroundId = CInt(draggedRow.RowInfo.Cells("BackgroundId").Value)
            Me.RadScheduler1.Appointments.Add(appointment)

            dataRowView.Row.Table.Rows.Remove(dataRowView.Row)
        Else
            Throw New ApplicationException("Unhandled Scenario")
        End If
    End If
End Sub

```

> note The start date of the created appointment is in correspondence with the cell where the row is dropped. The appointment’s duration is relevant to the original duration.

> caption Figure 1: Drag and Drop from RadGridView to RadScheduler

![WinForms RadScheduler Drag and Drop from RadGridView to RadScheduler](https://www.telerik.com/products/winforms/documentation/assets/038c4bd1620f328509be7916d71df892/scheduler-drag-and-drop-drag-and-drop-using-raddragdropservice001.gif)

## Drag and Drop from RadScheduler to RadGridView

To implement drag and drop functionality for this scenario, we will use the SchedulerElement.**DragDropBehavior**, which is a derivative of the **RadDragDropService**. Subscribe to its **PreviewDragOver** and **PreviewDragDrop** events. In the **PreviewDragOver** event allow dropping over a row element or over the table element. The **PreviewDragDrop** event performs the actual inserting of the dragged appointment into the **RadGridView**’s data source:

```C#
private void DragDropBehavior_PreviewDragOver(object sender, Telerik.WinControls.RadDragOverEventArgs e)
{
    e.CanDrop = e.HitTarget is GridTableElement ||
                e.HitTarget is GridDataRowElement;
}

private void DragDropBehavior_PreviewDragDrop(object sender, Telerik.WinControls.RadDropEventArgs e)
{
    DragFeedbackElement draggedInstance = e.DragInstance as DragFeedbackElement;
    if (draggedInstance == null)
    {
        return;
    }
    GridDataRowElement rowElement = e.HitTarget as GridDataRowElement;
    GridTableElement tableElement = e.HitTarget as GridTableElement;
    RadGridView targetGrid;
    if (rowElement == null && tableElement == null)
    {
        return;
    }
    if (rowElement != null)
    {
        targetGrid = rowElement.GridViewElement.GridControl;
    }
    else
    {
        targetGrid = tableElement.GridViewElement.GridControl;
    }
    
    if (targetGrid == null)
    {
        return;
    }
    e.Handled = true;
    
    int index = rowElement != null ? this.GetTargetRowIndex(rowElement, e.DropLocation) : targetGrid.RowCount;
    Appointment draggedAppointment = draggedInstance.AssociatedAppointment as Appointment;
    this.MoveRows(targetGrid, draggedAppointment, index);
}

private int GetTargetRowIndex(GridDataRowElement row, Point dropLocation)
{
    int halfHeight = row.Size.Height / 2;
    int index = row.RowInfo.Index;
    if (dropLocation.Y > halfHeight)
    {
        index++;
    }
    return index;
}

private void MoveRows(RadGridView dragGrid,
    Appointment draggedAppointment, int index)
{
    dragGrid.BeginUpdate();
    
    if (dragGrid.DataSource != null && typeof(BindingSource).IsAssignableFrom(dragGrid.DataSource.GetType()))
    {
        //bound to a BindingSource scenario
        BindingSource sourceCollection = (BindingSource)dragGrid.DataSource;
        this.radScheduler1.Appointments.Remove(draggedAppointment);
        
        DataRowView newDataRowView = sourceCollection.AddNew() as DataRowView;
        if (newDataRowView != null)
        {
            newDataRowView["Start"] = draggedAppointment.Start;
            newDataRowView["End"] = draggedAppointment.End ;
            newDataRowView["Summary"] = draggedAppointment.Summary;
            newDataRowView["Description"] = draggedAppointment.Description ;
            newDataRowView["Location"] = draggedAppointment.Location;
            newDataRowView["StatusId"] = draggedAppointment.StatusId;
            newDataRowView["BackgroundId"] = draggedAppointment.BackgroundId ;
        }
        newDataRowView.Row.Table.Rows.InsertAt(newDataRowView.Row, index);
    }
    else
    {
        throw new ApplicationException("Unhandled Scenario");
    }
    
    dragGrid.EndUpdate(true);
}
    
```

```VB.NET
Private Sub DragDropBehavior_PreviewDragOver(sender As Object, e As Telerik.WinControls.RadDragOverEventArgs)
    e.CanDrop = TypeOf e.HitTarget Is GridTableElement OrElse TypeOf e.HitTarget Is GridDataRowElement
End Sub

Private Sub DragDropBehavior_PreviewDragDrop(sender As Object, e As Telerik.WinControls.RadDropEventArgs)
    Dim draggedInstance As DragFeedbackElement = TryCast(e.DragInstance, DragFeedbackElement)
    If draggedInstance Is Nothing Then
        Return
    End If
    Dim rowElement As GridDataRowElement = TryCast(e.HitTarget, GridDataRowElement)
    Dim tableElement As GridTableElement = TryCast(e.HitTarget, GridTableElement)
    Dim targetGrid As RadGridView
    If rowElement Is Nothing AndAlso tableElement Is Nothing Then
        Return
    End If
    If rowElement IsNot Nothing Then
        targetGrid = rowElement.GridViewElement.GridControl
    Else
        targetGrid = tableElement.GridViewElement.GridControl
    End If

    If targetGrid Is Nothing Then
        Return
    End If
    e.Handled = True

    Dim index As Integer = If(rowElement IsNot Nothing, Me.GetTargetRowIndex(rowElement, e.DropLocation), targetGrid.RowCount)
    Dim draggedAppointment As Appointment = TryCast(draggedInstance.AssociatedAppointment, Appointment)
    Me.MoveRows(targetGrid, draggedAppointment, index)
End Sub

Private Function GetTargetRowIndex(row As GridDataRowElement, dropLocation As Point) As Integer
    Dim halfHeight As Integer = row.Size.Height / 2
    Dim index As Integer = row.RowInfo.Index
    If dropLocation.Y > halfHeight Then
        index += 1
    End If
    Return index
End Function

Private Sub MoveRows(dragGrid As RadGridView, draggedAppointment As Appointment, index As Integer)
    dragGrid.BeginUpdate()

    If dragGrid.DataSource IsNot Nothing AndAlso GetType(BindingSource).IsAssignableFrom(dragGrid.DataSource.[GetType]()) Then
        'bound to a BindingSource scenario
        Dim sourceCollection As BindingSource = DirectCast(dragGrid.DataSource, BindingSource)
        Me.RadScheduler1.Appointments.Remove(draggedAppointment)

        Dim newDataRowView As DataRowView = TryCast(sourceCollection.AddNew(), DataRowView)
        If newDataRowView IsNot Nothing Then
            newDataRowView("Start") = draggedAppointment.Start
            newDataRowView("End") = draggedAppointment.[End]
            newDataRowView("Summary") = draggedAppointment.Summary
            newDataRowView("Description") = draggedAppointment.Description
            newDataRowView("Location") = draggedAppointment.Location
            newDataRowView("StatusId") = draggedAppointment.StatusId
            newDataRowView("BackgroundId") = draggedAppointment.BackgroundId
        End If
        newDataRowView.Row.Table.Rows.InsertAt(newDataRowView.Row, index)
    Else
        Throw New ApplicationException("Unhandled Scenario")
    End If

    dragGrid.EndUpdate(True)
End Sub

```

> caption Figure 2: Drag and Drop from RadScheduler to RadGridView

![WinForms RadScheduler Drag and Drop from RadScheduler to RadGridView](https://www.telerik.com/products/winforms/documentation/assets/f723be0ee2121200e527d4ec48c7c596/scheduler-drag-and-drop-drag-and-drop-using-raddragdropservice002.gif)

## See Also

* [Views](https://www.telerik.com/products/winforms/documentation/controls/scheduler/views/overview-and-structure)
* [Working with Appointments](https://www.telerik.com/products/winforms/documentation/controls/scheduler/appointments-and-dialogs/working-with-appointments)
* [Formatting Appointments](https://www.telerik.com/products/winforms/documentation/controls/scheduler/appearance/formatting-appointments)
* [Scheduler Element Provider](https://www.telerik.com/products/winforms/documentation/controls/scheduler/fundamentals/scheduler-element-provider-)