How to move ListView items between ListViews
Posted: Thu Mar 01, 2012 2:08 pm
Moving items from one ListView to another is not something included in the .NET Framework. This tutorial will show you how to accomplish it yourself.
First, create your Windows Forms Project and add a ListView to Form1.
We will use 4 events from the ListView: ItemDrag, DragEnter, DragOver and DragDrop.
The code for ItemDrag:
The DataObject class is a class to store the format and data of anything that is being dragged in a drag-drop operation. Then we use the DoDragDrop method in the ListView to start the operation. The second parameters specify which effects are applied to the mouse cursor.
The next piece is the DragEnter event. It is excecuted when the mouse enters the ListView during a drag-drop operation.
First it checks if the "ListViewItem()" format is on the drag-drop 'clipboard'. If it is, it continues to check if the Control key is down. The mouse effect is Copy if it is pressed, and only move if its not pressed. If the "ListViewItem()" data format is not available then there is no effect and the drop will not be accepted.
The 3rd handler is the DragOver event, it is executed whenever the mouse is over the ListView's bounds with something dragged. The code is the same as the DragEnter code, but it updates all the time so the the mouse cursor looks as it would either copy or move the items.
The last event to handle is the DragDrop event. When you drop the items, we have to update the items in both the ListView where the items were, and the ListView they are dropped to.
First, create your Windows Forms Project and add a ListView to Form1.
We will use 4 events from the ListView: ItemDrag, DragEnter, DragOver and DragDrop.
The code for ItemDrag:
Code: Select all
This collects every selected item in the ListView and stores them in a DataObject class. Private Sub ListView1_ItemDrag(sender As System.Object, e As System.Windows.Forms.ItemDragEventArgs) Handles ListView1.ItemDrag
Dim items(ListView1.SelectedItems.Count - 1) As ListViewItem
For i = 0 To ListView1.SelectedItems.Count - 1
items(i) = ListView1.SelectedItems(i)
Next
Dim data As New DataObject("ListViewItem()", items)
ListView1.DoDragDrop(data, DragDropEffects.Copy Or DragDropEffects.Move)
End SubThe DataObject class is a class to store the format and data of anything that is being dragged in a drag-drop operation. Then we use the DoDragDrop method in the ListView to start the operation. The second parameters specify which effects are applied to the mouse cursor.
The next piece is the DragEnter event. It is excecuted when the mouse enters the ListView during a drag-drop operation.
Code: Select all
Private Sub ListView1_DragEnter(sender As System.Object, e As System.Windows.Forms.DragEventArgs) Handles ListView1.DragEnter
If e.Data.GetDataPresent("ListViewItem()") Then
If (e.KeyState And 8) = 8 Then 'Check if control key is down
e.Effect = DragDropEffects.Copy
Else
e.Effect = DragDropEffects.Move
End If
Else
e.Effect = DragDropEffects.None
End If
End SubFirst it checks if the "ListViewItem()" format is on the drag-drop 'clipboard'. If it is, it continues to check if the Control key is down. The mouse effect is Copy if it is pressed, and only move if its not pressed. If the "ListViewItem()" data format is not available then there is no effect and the drop will not be accepted.
The 3rd handler is the DragOver event, it is executed whenever the mouse is over the ListView's bounds with something dragged. The code is the same as the DragEnter code, but it updates all the time so the the mouse cursor looks as it would either copy or move the items.
The last event to handle is the DragDrop event. When you drop the items, we have to update the items in both the ListView where the items were, and the ListView they are dropped to.
Code: Select all
This checks if there is data associated with the "ListViewItem()" format. If there is, it saves the items in a ListViewItem() variabe. If the Control key is down, it clones every item and adds it to the new ListView, but if not, it removes every item from the previous ListView and adds them to the new. Private Sub ListView1_DragDrop(sender As System.Object, e As System.Windows.Forms.DragEventArgs) Handles ListView1.DragDrop
If e.Data.GetDataPresent("ListViewItem()") Then
Dim items As ListViewItem() = DirectCast(e.Data.GetData("ListViewItem()"), ListViewItem())
If (e.KeyState And 8) = 8 Then 'Check if control key is down
For Each i As ListViewItem In items
ListView1.Items.Add(i.Clone)
Next
Else
For Each i As ListViewItem In items
i.Remove()
Next
ListView1.Items.AddRange(items)
End If
Else
e.Effect = DragDropEffects.None
End If
End Sub
