Proprietà ListView.InsertionMark (System.Windows.Forms)

Imports System
Imports System.Drawing
Imports System.Windows.Forms

Public Class ListViewInsertionMarkExample
    Inherits Form

    Private myListView As ListView
    
    Public Sub New()
        ' Initialize myListView.
        myListView = New ListView()
        myListView.Dock = DockStyle.Fill
        myListView.View = View.LargeIcon
        myListView.MultiSelect = False
        myListView.ListViewItemSorter = New ListViewIndexComparer()
        
        ' Initialize the insertion mark.
        myListView.InsertionMark.Color = Color.Green
        
        ' Add items to myListView.
        myListView.Items.Add("zero")
        myListView.Items.Add("one")
        myListView.Items.Add("two")
        myListView.Items.Add("three")
        myListView.Items.Add("four")
        myListView.Items.Add("five")
        
        ' Initialize the drag-and-drop operation when running
        ' under Windows XP or a later operating system.
        If OSFeature.Feature.IsPresent(OSFeature.Themes)
            myListView.AllowDrop = True
            AddHandler myListView.ItemDrag, AddressOf myListView_ItemDrag
            AddHandler myListView.DragEnter, AddressOf myListView_DragEnter
            AddHandler myListView.DragOver, AddressOf myListView_DragOver
            AddHandler myListView.DragLeave, AddressOf myListView_DragLeave
            AddHandler myListView.DragDrop, AddressOf myListView_DragDrop
        End If 

        ' Initialize the form.
        Me.Text = "ListView Insertion Mark Example"
        Me.Controls.Add(myListView)
    End Sub 'New

    <STAThread()> _
    Shared Sub Main()
        Application.EnableVisualStyles()
        Application.Run(New ListViewInsertionMarkExample())
    End Sub 'Main
    
    ' Starts the drag-and-drop operation when an item is dragged.
    Private Sub myListView_ItemDrag(sender As Object, e As ItemDragEventArgs)
        myListView.DoDragDrop(e.Item, DragDropEffects.Move)
    End Sub 'myListView_ItemDrag
    
    ' Sets the target drop effect.
    Private Sub myListView_DragEnter(sender As Object, e As DragEventArgs)
        e.Effect = e.AllowedEffect
    End Sub 'myListView_DragEnter
    
    ' Moves the insertion mark as the item is dragged.
    Private Sub myListView_DragOver(sender As Object, e As DragEventArgs)
        ' Retrieve the client coordinates of the mouse pointer.
        Dim targetPoint As Point = myListView.PointToClient(New Point(e.X, e.Y))
        
        ' Retrieve the index of the item closest to the mouse pointer.
        Dim targetIndex As Integer = _
            myListView.InsertionMark.NearestIndex(targetPoint)
        
        ' Confirm that the mouse pointer is not over the dragged item.
        If targetIndex > -1 Then
            ' Determine whether the mouse pointer is to the left or
            ' the right of the midpoint of the closest item and set
            ' the InsertionMark.AppearsAfterItem property accordingly.
            Dim itemBounds As Rectangle = myListView.GetItemRect(targetIndex)
            If targetPoint.X > itemBounds.Left + (itemBounds.Width / 2) Then
                myListView.InsertionMark.AppearsAfterItem = True
            Else
                myListView.InsertionMark.AppearsAfterItem = False
            End If
        End If
        
        ' Set the location of the insertion mark. If the mouse is
        ' over the dragged item, the targetIndex value is -1 and
        ' the insertion mark disappears.
        myListView.InsertionMark.Index = targetIndex
    End Sub 'myListView_DragOver

    ' Removes the insertion mark when the mouse leaves the control.
    Private Sub myListView_DragLeave(sender As Object, e As EventArgs)
        myListView.InsertionMark.Index = -1
    End Sub 'myListView_DragLeave
    
    ' Moves the item to the location of the insertion mark.
    Private Sub myListView_DragDrop(sender As Object, e As DragEventArgs)
        ' Retrieve the index of the insertion mark;
        Dim targetIndex As Integer = myListView.InsertionMark.Index
        
        ' If the insertion mark is not visible, exit the method.
        If targetIndex = -1 Then
            Return
        End If 

        ' If the insertion mark is to the right of the item with
        ' the corresponding index, increment the target index.
        If myListView.InsertionMark.AppearsAfterItem Then
            targetIndex += 1
        End If 

        ' Retrieve the dragged item.
        Dim draggedItem As ListViewItem = _
            CType(e.Data.GetData(GetType(ListViewItem)), ListViewItem)
        
        ' Insert a copy of the dragged item at the target index.
        ' A copy must be inserted before the original item is removed
        ' to preserve item index values.
        myListView.Items.Insert(targetIndex, _
            CType(draggedItem.Clone(), ListViewItem))
        
        ' Remove the original copy of the dragged item.
        myListView.Items.Remove(draggedItem)

    End Sub 'myListView_DragDrop
    
    ' Sorts ListViewItem objects by index.    
    Private Class ListViewIndexComparer
        Implements System.Collections.IComparer
        
        Public Function Compare(x As Object, y As Object) As Integer _
            Implements System.Collections.IComparer.Compare
            Return CType(x, ListViewItem).Index - CType(y, ListViewItem).Index
        End Function 'Compare

    End Class 'ListViewIndexComparer

End Class 'ListViewInsertionMarkExample 

using System;
using System.Drawing;
using System.Windows.Forms;

public class ListViewInsertionMarkExample : Form
{
    private ListView myListView; 

    public ListViewInsertionMarkExample()
    {
        // Initialize myListView.
        myListView = new ListView();
        myListView.Dock = DockStyle.Fill;
        myListView.View = View.LargeIcon;
        myListView.MultiSelect = false;
        myListView.ListViewItemSorter = new ListViewIndexComparer();

        // Initialize the insertion mark.
        myListView.InsertionMark.Color = Color.Green;

        // Add items to myListView.
        myListView.Items.Add("zero");
        myListView.Items.Add("one");
        myListView.Items.Add("two");
        myListView.Items.Add("three");
        myListView.Items.Add("four");
        myListView.Items.Add("five");
        
        // Initialize the drag-and-drop operation when running
        // under Windows XP or a later operating system.
        if (OSFeature.Feature.IsPresent(OSFeature.Themes))
        {
            myListView.AllowDrop = true;
            myListView.ItemDrag += new ItemDragEventHandler(myListView_ItemDrag);
            myListView.DragEnter += new DragEventHandler(myListView_DragEnter);
            myListView.DragOver += new DragEventHandler(myListView_DragOver);
            myListView.DragLeave += new EventHandler(myListView_DragLeave);
            myListView.DragDrop += new DragEventHandler(myListView_DragDrop);
        }

        // Initialize the form.
        this.Text = "ListView Insertion Mark Example";
        this.Controls.Add(myListView);
    }

    [STAThread]
    static void Main() 
    {
        Application.EnableVisualStyles();
        Application.Run(new ListViewInsertionMarkExample());
    }

    // Starts the drag-and-drop operation when an item is dragged.
    private void myListView_ItemDrag(object sender, ItemDragEventArgs e)
    {
        myListView.DoDragDrop(e.Item, DragDropEffects.Move);
    }

    // Sets the target drop effect.
    private void myListView_DragEnter(object sender, DragEventArgs e)
    {
        e.Effect = e.AllowedEffect;
    }

    // Moves the insertion mark as the item is dragged.
    private void myListView_DragOver(object sender, DragEventArgs e)
    {
        // Retrieve the client coordinates of the mouse pointer.
        Point targetPoint = 
            myListView.PointToClient(new Point(e.X, e.Y));

        // Retrieve the index of the item closest to the mouse pointer.
        int targetIndex = myListView.InsertionMark.NearestIndex(targetPoint);

        // Confirm that the mouse pointer is not over the dragged item.
        if (targetIndex > -1) 
        {
            // Determine whether the mouse pointer is to the left or
            // the right of the midpoint of the closest item and set
            // the InsertionMark.AppearsAfterItem property accordingly.
            Rectangle itemBounds = myListView.GetItemRect(targetIndex);
            if ( targetPoint.X > itemBounds.Left + (itemBounds.Width / 2) )
            {
                myListView.InsertionMark.AppearsAfterItem = true;
            }
            else
            {
                myListView.InsertionMark.AppearsAfterItem = false;
            }
        }

        // Set the location of the insertion mark. If the mouse is
        // over the dragged item, the targetIndex value is -1 and
        // the insertion mark disappears.
        myListView.InsertionMark.Index = targetIndex;
    }

    // Removes the insertion mark when the mouse leaves the control.
    private void myListView_DragLeave(object sender, EventArgs e)
    {
        myListView.InsertionMark.Index = -1;
    }

    // Moves the item to the location of the insertion mark.
    private void myListView_DragDrop(object sender, DragEventArgs e)
    {
        // Retrieve the index of the insertion mark;
        int targetIndex = myListView.InsertionMark.Index;

        // If the insertion mark is not visible, exit the method.
        if (targetIndex == -1) 
        {
            return;
        }

        // If the insertion mark is to the right of the item with
        // the corresponding index, increment the target index.
        if (myListView.InsertionMark.AppearsAfterItem) 
        {
            targetIndex++;
        }

        // Retrieve the dragged item.
        ListViewItem draggedItem = 
            (ListViewItem)e.Data.GetData(typeof(ListViewItem));

        // Insert a copy of the dragged item at the target index.
        // A copy must be inserted before the original item is removed
        // to preserve item index values. 
        myListView.Items.Insert(
            targetIndex, (ListViewItem)draggedItem.Clone());

        // Remove the original copy of the dragged item.
        myListView.Items.Remove(draggedItem);
    }

    // Sorts ListViewItem objects by index.
    private class ListViewIndexComparer : System.Collections.IComparer
    {
        public int Compare(object x, object y)
        {
            return ((ListViewItem)x).Index - ((ListViewItem)y).Index;
        }
    }

}

#using <System.dll>
#using <System.Windows.Forms.dll>
#using <System.Drawing.dll>

using namespace System;
using namespace System::Drawing;
using namespace System::Windows::Forms;
public ref class ListViewInsertionMarkExample: public Form
{
private:
   ListView^ myListView;

public:

   ListViewInsertionMarkExample()
   {
      // Initialize myListView.
      myListView = gcnew ListView;
      myListView->Dock = DockStyle::Fill;
      myListView->View = View::LargeIcon;
      myListView->MultiSelect = false;
      myListView->ListViewItemSorter = gcnew ListViewIndexComparer;

      // Initialize the insertion mark.
      myListView->InsertionMark->Color = Color::Green;

      // Add items to myListView.
      myListView->Items->Add( "zero" );
      myListView->Items->Add( "one" );
      myListView->Items->Add( "two" );
      myListView->Items->Add( "three" );
      myListView->Items->Add( "four" );
      myListView->Items->Add( "five" );

      // Initialize the drag-and-drop operation when running
      // under Windows XP or a later operating system.
      if ( System::Environment::OSVersion->Version->Major > 5 || (System::Environment::OSVersion->Version->Major == 5 && System::Environment::OSVersion->Version->Minor >= 1) )
      {
         myListView->AllowDrop = true;
         myListView->ItemDrag += gcnew ItemDragEventHandler( this, &ListViewInsertionMarkExample::myListView_ItemDrag );
         myListView->DragEnter += gcnew DragEventHandler( this, &ListViewInsertionMarkExample::myListView_DragEnter );
         myListView->DragOver += gcnew DragEventHandler( this, &ListViewInsertionMarkExample::myListView_DragOver );
         myListView->DragLeave += gcnew EventHandler( this, &ListViewInsertionMarkExample::myListView_DragLeave );
         myListView->DragDrop += gcnew DragEventHandler( this, &ListViewInsertionMarkExample::myListView_DragDrop );
      }

      // Initialize the form.
      this->Text = "ListView Insertion Mark Example";
      this->Controls->Add( myListView );
   }

private:

   // Starts the drag-and-drop operation when an item is dragged.
   void myListView_ItemDrag( Object^ /*sender*/, ItemDragEventArgs^ e )
   {
      myListView->DoDragDrop( e->Item, DragDropEffects::Move );
   }

   // Sets the target drop effect.
   void myListView_DragEnter( Object^ /*sender*/, DragEventArgs^ e )
   {
      e->Effect = e->AllowedEffect;
   }

   // Moves the insertion mark as the item is dragged.
   void myListView_DragOver( Object^ /*sender*/, DragEventArgs^ e )
   {
      // Retrieve the client coordinates of the mouse pointer.
      Point targetPoint = myListView->PointToClient( Point(e->X,e->Y) );

      // Retrieve the index of the item closest to the mouse pointer.
      int targetIndex = myListView->InsertionMark->NearestIndex( targetPoint );

      // Confirm that the mouse pointer is not over the dragged item.
      if ( targetIndex > -1 )
      {
         // Determine whether the mouse pointer is to the left or
         // the right of the midpoint of the closest item and set
         // the InsertionMark.AppearsAfterItem property accordingly.
         Rectangle itemBounds = myListView->GetItemRect( targetIndex );
         if ( targetPoint.X > itemBounds.Left + (itemBounds.Width / 2) )
         {
            myListView->InsertionMark->AppearsAfterItem = true;
         }
         else
         {
            myListView->InsertionMark->AppearsAfterItem = false;
         }
      }

      // Set the location of the insertion mark. If the mouse is
      // over the dragged item, the targetIndex value is -1 and
      // the insertion mark disappears.
      myListView->InsertionMark->Index = targetIndex;
   }

   // Removes the insertion mark when the mouse leaves the control.
   void myListView_DragLeave( Object^ /*sender*/, EventArgs^ /*e*/ )
   {
      myListView->InsertionMark->Index = -1;
   }

   // Moves the item to the location of the insertion mark.
   void myListView_DragDrop( Object^ /*sender*/, DragEventArgs^ e )
   {
      // Retrieve the index of the insertion mark;
      int targetIndex = myListView->InsertionMark->Index;

      // If the insertion mark is not visible, exit the method.
      if ( targetIndex == -1 )
      {
         return;
      }

      // If the insertion mark is to the right of the item with
      // the corresponding index, increment the target index.
      if ( myListView->InsertionMark->AppearsAfterItem )
      {
         targetIndex++;
      }

      // Retrieve the dragged item.
      ListViewItem^ draggedItem = dynamic_cast<ListViewItem^>(e->Data->GetData( ListViewItem::typeid ));

      // Insert a copy of the dragged item at the target index.
      // A copy must be inserted before the original item is removed
      // to preserve item index values.
      myListView->Items->Insert( targetIndex, dynamic_cast<ListViewItem^>(draggedItem->Clone()) );

      // Remove the original copy of the dragged item.
      myListView->Items->Remove( draggedItem );

   }

   // Sorts ListViewItem objects by index.
   ref class ListViewIndexComparer: public System::Collections::IComparer
   {
   public:
      virtual int Compare( Object^ x, Object^ y )
      {
         return (dynamic_cast<ListViewItem^>(x))->Index - (dynamic_cast<ListViewItem^>(y))->Index;
      }
   };
};

[STAThread]
int main()
{
   Application::EnableVisualStyles();
   Application::Run( gcnew ListViewInsertionMarkExample );
}

import System.*;
import System.Drawing.*;
import System.Windows.Forms.*;

public class ListViewInsertionMarkExample extends Form
{
    private ListView myListView;

    public ListViewInsertionMarkExample()
    {
        // Initialize myListView.
        myListView = new ListView();
        myListView.set_Dock(DockStyle.Fill);
        myListView.set_View(View.LargeIcon);
        myListView.set_MultiSelect(false);
        myListView.set_ListViewItemSorter(new ListViewIndexComparer());
        // Initialize the insertion mark.
        myListView.get_InsertionMark().set_Color(Color.get_Green());
        // Add items to myListView.
        myListView.get_Items().Add("zero");
        myListView.get_Items().Add("one");
        myListView.get_Items().Add("two");
        myListView.get_Items().Add("three");
        myListView.get_Items().Add("four");
        myListView.get_Items().Add("five");
        // Initialize the drag-and-drop operation when running
        // under Windows XP or a later operating system.
        if (System.Environment.get_OSVersion().get_Version().get_Major() > 5 
            || (System.Environment.get_OSVersion().get_Version().get_Major() 
            == 5 && System.Environment.get_OSVersion().get_Version().
            get_Minor() >= 1)) {
            myListView.set_AllowDrop(true);
            myListView.add_ItemDrag(new ItemDragEventHandler(
                myListView_ItemDrag));
            myListView.add_DragEnter(new DragEventHandler(
                myListView_DragEnter));
            myListView.add_DragOver(new DragEventHandler(myListView_DragOver));
            myListView.add_DragLeave(new EventHandler(myListView_DragLeave));
            myListView.add_DragDrop(new DragEventHandler(myListView_DragDrop));
        }
        // Initialize the form.
        this.set_Text("ListView Insertion Mark Example");
        this.get_Controls().Add(myListView);
    } //ListViewInsertionMarkExample

    /** @attribute STAThread()
     */
    public static void main(String[] args)
    {
        Application.Run(new ListViewInsertionMarkExample());
    } //main

    // Starts the drag-and-drop operation when an item is dragged.
    private void myListView_ItemDrag(Object sender, ItemDragEventArgs e)
    {
        myListView.DoDragDrop(e.get_Item(), DragDropEffects.Move);
    } //myListView_ItemDrag

    // Sets the target drop effect.
    private void myListView_DragEnter(Object sender, DragEventArgs e)
    {
        e.set_Effect(e.get_AllowedEffect());
    } //myListView_DragEnter

    // Moves the insertion mark as the item is dragged.
    private void myListView_DragOver(Object sender, DragEventArgs e)
    {
        // Retrieve the client coordinates of the mouse pointer.
        Point targetPoint = myListView.PointToClient(
              new Point(e.get_X(), e.get_Y()));
        // Retrieve the index of the item closest to the mouse pointer.
        int targetIndex = myListView.get_InsertionMark().
            NearestIndex(targetPoint);
        // Confirm that the mouse pointer is not over the dragged item.
        if (targetIndex > -1) {
            // Determine whether the mouse pointer is to the left or
            // the right of the midpoint of the closest item and set
            // the InsertionMark.AppearsAfterItem property accordingly.
            Rectangle itemBounds = myListView.GetItemRect(targetIndex);
            if (targetPoint.get_X() > itemBounds.get_Left() 
                + itemBounds.get_Width() / 2) {
                myListView.get_InsertionMark().set_AppearsAfterItem(true);
            }
            else {
                myListView.get_InsertionMark().set_AppearsAfterItem(false);
            }
        }
        // Set the location of the insertion mark. If the mouse is
        // over the dragged item, the targetIndex value is -1 and
        // the insertion mark disappears.
        myListView.get_InsertionMark().set_Index(targetIndex);
    } //myListView_DragOver

    // Removes the insertion mark when the mouse leaves the control.
    private void myListView_DragLeave(Object sender, EventArgs e)
    {
        myListView.get_InsertionMark().set_Index(-1);
    } //myListView_DragLeave

    // Moves the item to the location of the insertion mark.
    private void myListView_DragDrop(Object sender, DragEventArgs e)
    {
        // Retrieve the index of the insertion mark;
        int targetIndex = myListView.get_InsertionMark().get_Index();
        // If the insertion mark is not visible, exit the method.
        if (targetIndex == -1) {
            return;
        }
        // If the insertion mark is to the right of the item with
        // the corresponding index, increment the target index.
        if (myListView.get_InsertionMark().get_AppearsAfterItem()) {
            targetIndex++;
        }
        // Retrieve the dragged item.
        ListViewItem draggedItem = (ListViewItem)(e.get_Data().GetData(
                     ListViewItem.class.ToType()));
        // Insert a copy of the dragged item at the target index.
        // A copy must be inserted before the original item is removed
        // to preserve item index values.
        myListView.get_Items().Insert(targetIndex, (ListViewItem)
            draggedItem.Clone());
        // Remove the original copy of the dragged item.
        myListView.get_Items().Remove(draggedItem);
    } //myListView_DragDrop

    // Sorts ListViewItem objects by index.
    private class ListViewIndexComparer 
        implements System.Collections.IComparer
    {
        public int Compare(Object x, Object y)
        {
            return ((ListViewItem)x).get_Index() 
                - ((ListViewItem)y).get_Index();
        } //Compare
    } //ListViewIndexComparer
} //ListViewInsertionMarkExample