Procedura: trascinare l'input penna
Nell'esempio seguente viene creata un'applicazione che consente all'utente di trascinare i tratti selezionati da un oggetto InkCanvas all'altro.
<Window x:Class="Window1"
xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml"
Title="InkDragDropSample" Height="500" Width="700"
>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<InkCanvas Name="ic1" AllowDrop="True"
Grid.Column="0" Grid.Row="0"
Margin="10,10,10,10" Background="AliceBlue"
PreviewMouseDown="InkCanvas_PreviewMouseDown"
Drop="InkCanvas_Drop"/>
<InkCanvas Name="ic2" AllowDrop="True"
Grid.Column="1" Grid.Row="0"
Margin="10,10,10,10" Background="Beige"
PreviewMouseDown="InkCanvas_PreviewMouseDown"
Drop="InkCanvas_Drop"/>
<CheckBox Grid.Row="1"
Checked="switchToSelect" Unchecked="switchToInk">
Select Mode
</CheckBox>
</Grid>
</Window>
Imports System
Imports System.IO
Imports System.Windows
Imports System.Windows.Ink
Imports System.Windows.Controls
Imports System.Windows.Data
Imports System.Windows.Input
Imports System.Windows.Media
Class Window1
Inherits Window
Public Sub New()
InitializeComponent()
End Sub 'New
Private Sub InkCanvas_PreviewMouseDown(ByVal sender As Object, _
ByVal e As MouseButtonEventArgs)
Dim ic As InkCanvas = CType(sender, InkCanvas)
Dim pt As Point = e.GetPosition(ic)
' If the user is moving selected strokes, prepare the strokes to be
' moved to another InkCanvas.
If ic.HitTestSelection(pt) = InkCanvasSelectionHitResult.Selection Then
Dim selectedStrokes As StrokeCollection = _
ic.GetSelectedStrokes()
Dim strokesToMove As StrokeCollection = _
selectedStrokes.Clone()
' Remove the offset of the selected strokes so they
' are positioned when the strokes are dropped.
Dim inkBounds As Rect = strokesToMove.GetBounds()
TranslateStrokes(strokesToMove, -inkBounds.X, -inkBounds.Y)
' Perform drag and drop.
Dim ms As New MemoryStream()
strokesToMove.Save(ms)
Dim dataObject As New DataObject _
(StrokeCollection.InkSerializedFormat, ms)
Dim effects As DragDropEffects = _
DragDrop.DoDragDrop(ic, dataObject, DragDropEffects.Move)
If (effects And DragDropEffects.Move) = DragDropEffects.Move Then
' Remove the selected strokes from the current InkCanvas.
ic.Strokes.Remove(selectedStrokes)
End If
End If
End Sub 'OnMouseDown
Private Sub InkCanvas_Drop(ByVal sender As Object, _
ByVal e As DragEventArgs)
' Get the strokes that were moved.
Dim ic As InkCanvas = CType(sender, InkCanvas)
Dim ms As MemoryStream = CType(e.Data.GetData( _
StrokeCollection.InkSerializedFormat), _
MemoryStream)
ms.Position = 0
Dim strokes As New StrokeCollection(ms)
' Translate the strokes to the position at which
' they were dropped.
Dim pt As Point = e.GetPosition(ic)
TranslateStrokes(strokes, pt.X, pt.Y)
' Add the strokes to the InkCanvas and keep them selected.
ic.Strokes.Add(strokes)
ic.Select(strokes)
End Sub 'OnDrop
' Helper method that transletes the specified strokes.
Sub TranslateStrokes(ByVal strokes As StrokeCollection, _
ByVal x As Double, ByVal y As Double)
Dim mat As New Matrix()
mat.Translate(x, y)
strokes.Transform(mat, False)
End Sub 'TranslateStrokes
Private Sub switchToSelect(ByVal sender As Object, _
ByVal e As RoutedEventArgs)
ic1.EditingMode = InkCanvasEditingMode.Select
ic2.EditingMode = InkCanvasEditingMode.Select
End Sub 'switchToSelect
Private Sub switchToInk(ByVal sender As Object, _
ByVal e As RoutedEventArgs)
ic1.EditingMode = InkCanvasEditingMode.Ink
ic2.EditingMode = InkCanvasEditingMode.Ink
End Sub 'switchToInk
End Class 'Window1
using System;
using System.IO;
using System.Windows;
using System.Windows.Ink;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Input;
using System.Windows.Media;
public partial class Window1 : Window
{
public Window1()
{
InitializeComponent();
}
void InkCanvas_PreviewMouseDown(object sender, MouseEventArgs e)
{
InkCanvas ic = (InkCanvas)sender;
Point pt = e.GetPosition(ic);
// If the user is moving selected strokes, prepare the strokes to be
// moved to another InkCanvas.
if (ic.HitTestSelection(pt) ==
InkCanvasSelectionHitResult.Selection)
{
StrokeCollection selectedStrokes = ic.GetSelectedStrokes();
StrokeCollection strokesToMove = selectedStrokes.Clone();
// Remove the offset of the selected strokes so they
// are positioned when the strokes are dropped.
Rect inkBounds = strokesToMove.GetBounds();
TranslateStrokes(strokesToMove, -inkBounds.X, -inkBounds.Y);
// Perform drag and drop.
MemoryStream ms = new MemoryStream();
strokesToMove.Save(ms);
DataObject dataObject = new DataObject(
StrokeCollection.InkSerializedFormat, ms);
DragDropEffects effects =
DragDrop.DoDragDrop(ic, dataObject,
DragDropEffects.Move);
if ((effects & DragDropEffects.Move) ==
DragDropEffects.Move)
{
// Remove the selected strokes
// from the current InkCanvas.
ic.Strokes.Remove(selectedStrokes);
}
}
}
void InkCanvas_Drop(object sender, DragEventArgs e)
{
// Get the strokes that were moved.
InkCanvas ic = (InkCanvas)sender;
MemoryStream ms = (MemoryStream)e.Data.GetData(
StrokeCollection.InkSerializedFormat);
ms.Position = 0;
StrokeCollection strokes = new StrokeCollection(ms);
// Translate the strokes to the position at which
// they were dropped.
Point pt = e.GetPosition(ic);
TranslateStrokes(strokes, pt.X, pt.Y);
// Add the strokes to the InkCanvas and keep them selected.
ic.Strokes.Add(strokes);
ic.Select(strokes);
}
// Helper method that transletes the specified strokes.
void TranslateStrokes(StrokeCollection strokes,
double x, double y)
{
Matrix mat = new Matrix();
mat.Translate(x, y);
strokes.Transform(mat, false);
}
void switchToSelect(object sender, RoutedEventArgs e)
{
ic1.EditingMode = InkCanvasEditingMode.Select;
ic2.EditingMode = InkCanvasEditingMode.Select;
}
void switchToInk(object sender, RoutedEventArgs e)
{
ic1.EditingMode = InkCanvasEditingMode.Ink;
ic2.EditingMode = InkCanvasEditingMode.Ink;
}
}