Cómo: Seleccionar entradas manuscritas desde un control personalizado
Al agregar un IncrementalLassoHitTester a su control personalizado, puede habilitar su control para que un usuario pueda seleccionar la entrada manuscrita con una herramienta de lazo, de forma similar a como el InkCanvas selecciona la entrada manuscrita con un lazo.
En este ejemplo se supone que está familiarizado con la creación de un control personalizado habilitado para la entrada manuscrita. Para crear un control personalizado que acepte la entrada manuscrita, vea Crear un control de entrada manuscrita.
Ejemplo
Cuando el usuario dibuja un lazo, IncrementalLassoHitTester predice qué trazos estarán dentro de los límites de la trayectoria del lazo después de que el usuario complete el lazo. Los trazos que se determinan que están dentro de los límites de la trayectoria del lazo se pueden considerar como seleccionados. Los trazos seleccionados también pueden deseleccionarse. Por ejemplo, si el usuario invierte la dirección mientras dibuja el lazo, el IncrementalLassoHitTester puede deseleccionar algunos trazos.
El IncrementalLassoHitTester genera el evento SelectionChanged, que permite que su control personalizado responda mientras el usuario está dibujando el lazo. Por ejemplo, puede cambiar la apariencia de los trazos a medida que el usuario las selecciona y anula la selección.
Administración del modo de entrada manuscrita
Resulta útil para el usuario si el lazo aparece de forma diferente a la entrada manuscrita del control. Para ello, el control personalizado debe realizar un seguimiento de si el usuario está escribiendo o seleccionando entrada manuscrita. La manera más fácil de hacerlo es declarar una enumeración con dos valores: uno para indicar que el usuario está escribiendo con entrada manuscrita y otro para indicar que el usuario está seleccionando la entrada manuscrita.
// Enum that keeps track of whether StrokeCollectionDemo is in ink mode
// or select mode.
public enum InkMode
{
Ink, Select
}
' Enum that keeps track of whether StrokeCollectionDemo is in ink mode
' or select mode.
Public Enum InkMode
Ink
[Select]
End Enum 'InkMode
A continuación, agregue dos DrawingAttributes a la clase: uno para usar cuando el usuario escriba con entrada manuscrita, otro para usar cuando el usuario seleccione la entrada manuscrita. En el constructor, inicialice el DrawingAttributes y adjunte ambos eventos AttributeChanged al mismo controlador de eventos. A continuación, establezca la propiedad DrawingAttributes de DynamicRenderer a la entrada manuscrita DrawingAttributes.
DrawingAttributes inkDA;
DrawingAttributes selectDA;
Private inkDA As DrawingAttributes
Private selectDA As DrawingAttributes
// In the constructor.
// Selection drawing attributes use dark gray ink.
selectDA = new DrawingAttributes();
selectDA.Color = Colors.DarkGray;
// ink drawing attributes use default attributes
inkDA = new DrawingAttributes();
inkDA.Width = 5;
inkDA.Height = 5;
inkDA.AttributeChanged += new PropertyDataChangedEventHandler(DrawingAttributesChanged);
selectDA.AttributeChanged += new PropertyDataChangedEventHandler(DrawingAttributesChanged);
' In the constructor.
' Selection drawing attributes use dark gray ink.
selectDA = New DrawingAttributes()
selectDA.Color = Colors.DarkGray
' ink drawing attributes use default attributes
inkDA = New DrawingAttributes()
inkDA.Width = 5
inkDA.Height = 5
AddHandler inkDA.AttributeChanged, _
AddressOf DrawingAttributesChanged
AddHandler selectDA.AttributeChanged, _
AddressOf DrawingAttributesChanged
Agregue una propiedad que exponga el modo de selección. Cuando el usuario cambie el modo de selección, establezca la propiedad DrawingAttributes del DynamicRenderer al objeto DrawingAttributes apropiado y luego vuelva a unir la propiedad RootVisual al InkPresenter.
// Property to indicate whether the user is inputting or
// selecting ink.
public InkMode Mode
{
get
{
return mode;
}
set
{
mode = value;
// Set the DrawingAttributes of the DynamicRenderer
if (mode == InkMode.Ink)
{
renderer.DrawingAttributes = inkDA;
}
else
{
renderer.DrawingAttributes = selectDA;
}
// Reattach the visual of the DynamicRenderer to the InkPresenter.
presenter.DetachVisuals(renderer.RootVisual);
presenter.AttachVisuals(renderer.RootVisual, renderer.DrawingAttributes);
}
}
' Property to indicate whether the user is inputting or
' selecting ink.
Public Property Mode() As InkMode
Get
Return Mode
End Get
Set(ByVal value As InkMode)
modeState = value
' Set the DrawingAttributes of the DynamicRenderer
If modeState = InkMode.Ink Then
renderer.DrawingAttributes = inkDA
Else
renderer.DrawingAttributes = selectDA
End If
' Reattach the visual of the DynamicRenderer to the InkPresenter.
presenter.DetachVisuals(renderer.RootVisual)
presenter.AttachVisuals(renderer.RootVisual, renderer.DrawingAttributes)
End Set
End Property
Exponga los DrawingAttributes como propiedades para que las aplicaciones puedan determinar la apariencia de los trazos de entrada manuscrita y los trazos de selección.
// Property to allow the user to change the pen's DrawingAttributes.
public DrawingAttributes InkDrawingAttributes
{
get
{
return inkDA;
}
}
// Property to allow the user to change the Selector'newStroke DrawingAttributes.
public DrawingAttributes SelectDrawingAttributes
{
get
{
return selectDA;
}
}
' Property to allow the user to change the pen's DrawingAttributes.
Public ReadOnly Property InkDrawingAttributes() As DrawingAttributes
Get
Return inkDA
End Get
End Property
' Property to allow the user to change the Selector'newStroke DrawingAttributes.
Public ReadOnly Property SelectDrawingAttributes() As DrawingAttributes
Get
Return selectDA
End Get
End Property
Cuando una propiedad de un objeto DrawingAttributes cambia, el RootVisual debe volver a unirse al InkPresenter. En el controlador de eventos del evento AttributeChanged, vuelva a unir el RootVisual al InkPresenter.
void DrawingAttributesChanged(object sender, PropertyDataChangedEventArgs e)
{
// Reattach the visual of the DynamicRenderer to the InkPresenter
// whenever the DrawingAttributes change.
presenter.DetachVisuals(renderer.RootVisual);
presenter.AttachVisuals(renderer.RootVisual, renderer.DrawingAttributes);
}
Private Sub DrawingAttributesChanged(ByVal sender As Object, _
ByVal e As PropertyDataChangedEventArgs)
' Reattach the visual of the DynamicRenderer to the InkPresenter
' whenever the DrawingAttributes change.
presenter.DetachVisuals(renderer.RootVisual)
presenter.AttachVisuals(renderer.RootVisual, _
renderer.DrawingAttributes)
End Sub
Uso de IncrementalLassoHitTester
Cree e inicialice un StrokeCollection que contenga los trazos seleccionados.
// StylusPointCollection that collects the stylus points from the stylus events.
StylusPointCollection stylusPoints;
' StylusPointCollection that collects the stylus points from the stylus events.
Private stylusPoints As StylusPointCollection
Cuando el usuario comienza a dibujar un trazo, ya sea la entrada manuscrita o el lazo, anule la selección de los trazos seleccionados. A continuación, si el usuario está dibujando un lazo, cree un IncrementalLassoHitTester llamando a GetIncrementalLassoHitTester, suscríbase al evento SelectionChanged y llame a AddPoints. Este código puede ser un método independiente y llamar desde los métodos OnStylusDown y OnMouseDown.
private void InitializeHitTester(StylusPointCollection collectedPoints)
{
// Deselect any selected strokes.
foreach (Stroke selectedStroke in selectedStrokes)
{
selectedStroke.DrawingAttributes.Color = inkDA.Color;
}
selectedStrokes.Clear();
if (mode == InkMode.Select)
{
// Remove the previously drawn lasso, if it exists.
if (lassoPath != null)
{
presenter.Strokes.Remove(lassoPath);
lassoPath = null;
}
selectionTester =
presenter.Strokes.GetIncrementalLassoHitTester(80);
selectionTester.SelectionChanged +=
new LassoSelectionChangedEventHandler(selectionTester_SelectionChanged);
selectionTester.AddPoints(collectedPoints);
}
}
Private Sub InitializeHitTester(ByVal collectedPoints As StylusPointCollection)
' Deselect any selected strokes.
Dim selectedStroke As Stroke
For Each selectedStroke In selectedStrokes
selectedStroke.DrawingAttributes.Color = inkDA.Color
Next selectedStroke
selectedStrokes.Clear()
If modeState = InkMode.Select Then
' Remove the previously drawn lasso, if it exists.
If Not (lassoPath Is Nothing) Then
presenter.Strokes.Remove(lassoPath)
lassoPath = Nothing
End If
selectionTester = presenter.Strokes.GetIncrementalLassoHitTester(80)
AddHandler selectionTester.SelectionChanged, AddressOf selectionTester_SelectionChanged
selectionTester.AddPoints(collectedPoints)
End If
End Sub
Añade los puntos del lápiz a IncrementalLassoHitTester mientras el usuario dibuja el lazo. Llame al siguiente método desde los métodos OnStylusMove, OnStylusUp, OnMouseMove y OnMouseLeftButtonUp.
private void AddPointsToHitTester(StylusPointCollection collectedPoints)
{
if (mode == InkMode.Select &&
selectionTester != null &&
selectionTester.IsValid)
{
// When the control is selecting strokes, add the
// stylus packetList to selectionTester.
selectionTester.AddPoints(collectedPoints);
}
}
Private Sub AddPointsToHitTester(ByVal collectedPoints As StylusPointCollection)
If modeState = InkMode.Select AndAlso _
Not selectionTester Is Nothing AndAlso _
selectionTester.IsValid Then
' When the control is selecting strokes, add the
' stylus packetList to selectionTester.
selectionTester.AddPoints(collectedPoints)
End If
End Sub
Controle el evento IncrementalLassoHitTester.SelectionChanged para responder cuando el usuario seleccione y anule la selección de trazos. La clase LassoSelectionChangedEventArgs tiene las propiedades SelectedStrokes y DeselectedStrokes que obtienen los trazos que fueron seleccionados y no seleccionados, respectivamente.
void selectionTester_SelectionChanged(object sender,
LassoSelectionChangedEventArgs args)
{
// Change the color of all selected strokes to red.
foreach (Stroke selectedStroke in args.SelectedStrokes)
{
selectedStroke.DrawingAttributes.Color = Colors.Red;
selectedStrokes.Add(selectedStroke);
}
// Change the color of all unselected strokes to
// their original color.
foreach (Stroke unselectedStroke in args.DeselectedStrokes)
{
unselectedStroke.DrawingAttributes.Color = inkDA.Color;
selectedStrokes.Remove(unselectedStroke);
}
}
Private Sub selectionTester_SelectionChanged(ByVal sender As Object, _
ByVal args As LassoSelectionChangedEventArgs)
' Change the color of all selected strokes to red.
Dim selectedStroke As Stroke
For Each selectedStroke In args.SelectedStrokes
selectedStroke.DrawingAttributes.Color = Colors.Red
selectedStrokes.Add(selectedStroke)
Next selectedStroke
' Change the color of all unselected strokes to
' their original color.
Dim unselectedStroke As Stroke
For Each unselectedStroke In args.DeselectedStrokes
unselectedStroke.DrawingAttributes.Color = inkDA.Color
selectedStrokes.Remove(unselectedStroke)
Next unselectedStroke
End Sub
Cuando el usuario termine de dibujar el lazo, cancele la suscripción al evento SelectionChanged y llame a EndHitTesting.
if (mode == InkMode.Select && lassoPath == null)
{
// Add the lasso to the InkPresenter and add the packetList
// to selectionTester.
lassoPath = newStroke;
lassoPath.DrawingAttributes = selectDA.Clone();
presenter.Strokes.Add(lassoPath);
selectionTester.SelectionChanged -= new LassoSelectionChangedEventHandler
(selectionTester_SelectionChanged);
selectionTester.EndHitTesting();
}
If modeState = InkMode.Select AndAlso lassoPath Is Nothing Then
' Add the lasso to the InkPresenter and add the packetList
' to selectionTester.
lassoPath = newStroke
lassoPath.DrawingAttributes = selectDA.Clone()
presenter.Strokes.Add(lassoPath)
RemoveHandler selectionTester.SelectionChanged, _
AddressOf selectionTester_SelectionChanged
selectionTester.EndHitTesting()
End If
En resumen:
El ejemplo siguiente es un control personalizado que permite a un usuario seleccionar la entrada manuscrita con un lazo.
using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Input;
using System.Windows.Input.StylusPlugIns;
using System.Windows.Ink;
// Enum that keeps track of whether StrokeCollectionDemo is in ink mode
// or select mode.
public enum InkMode
{
Ink, Select
}
// This control allows the user to input and select ink. When the
// user selects ink, the lasso remains visible until they erase, or clip
// the selected strokes, or clear the selection. When the control is
// in selection mode, strokes that are selected turn red.
public class InkSelector : Label
{
InkMode mode;
DrawingAttributes inkDA;
DrawingAttributes selectDA;
InkPresenter presenter;
IncrementalLassoHitTester selectionTester;
StrokeCollection selectedStrokes = new StrokeCollection();
// StylusPointCollection that collects the stylus points from the stylus events.
StylusPointCollection stylusPoints;
// Stroke that represents the lasso.
Stroke lassoPath;
DynamicRenderer renderer;
public InkSelector()
{
mode = InkMode.Ink;
// Use an InkPresenter to display the strokes on the custom control.
presenter = new InkPresenter();
this.Content = presenter;
// In the constructor.
// Selection drawing attributes use dark gray ink.
selectDA = new DrawingAttributes();
selectDA.Color = Colors.DarkGray;
// ink drawing attributes use default attributes
inkDA = new DrawingAttributes();
inkDA.Width = 5;
inkDA.Height = 5;
inkDA.AttributeChanged += new PropertyDataChangedEventHandler(DrawingAttributesChanged);
selectDA.AttributeChanged += new PropertyDataChangedEventHandler(DrawingAttributesChanged);
// Add a DynmaicRenderer to the control so ink appears
// to "flow" from the tablet pen.
renderer = new DynamicRenderer();
renderer.DrawingAttributes = inkDA;
this.StylusPlugIns.Add(renderer);
presenter.AttachVisuals(renderer.RootVisual,
renderer.DrawingAttributes);
}
static InkSelector()
{
// Allow ink to be drawn only within the bounds of the control.
Type owner = typeof(InkSelector);
ClipToBoundsProperty.OverrideMetadata(owner,
new FrameworkPropertyMetadata(true));
}
// Prepare to collect stylus packets. If Mode is set to Select,
// get the IncrementalHitTester from the InkPresenter'newStroke
// StrokeCollection and subscribe to its StrokeHitChanged event.
protected override void OnStylusDown(StylusDownEventArgs e)
{
base.OnStylusDown(e);
Stylus.Capture(this);
// Create a new StylusPointCollection using the StylusPointDescription
// from the stylus points in the StylusDownEventArgs.
stylusPoints = new StylusPointCollection();
StylusPointCollection eventPoints = e.GetStylusPoints(this, stylusPoints.Description);
stylusPoints.Add(eventPoints);
InitializeHitTester(eventPoints);
}
protected override void OnMouseLeftButtonDown(MouseButtonEventArgs e)
{
base.OnMouseLeftButtonDown(e);
Mouse.Capture(this);
if (e.StylusDevice != null)
{
return;
}
Point pt = e.GetPosition(this);
StylusPointCollection collectedPoints = new StylusPointCollection(new Point[] { pt });
stylusPoints = new StylusPointCollection();
stylusPoints.Add(collectedPoints);
InitializeHitTester(collectedPoints);
}
private void InitializeHitTester(StylusPointCollection collectedPoints)
{
// Deselect any selected strokes.
foreach (Stroke selectedStroke in selectedStrokes)
{
selectedStroke.DrawingAttributes.Color = inkDA.Color;
}
selectedStrokes.Clear();
if (mode == InkMode.Select)
{
// Remove the previously drawn lasso, if it exists.
if (lassoPath != null)
{
presenter.Strokes.Remove(lassoPath);
lassoPath = null;
}
selectionTester =
presenter.Strokes.GetIncrementalLassoHitTester(80);
selectionTester.SelectionChanged +=
new LassoSelectionChangedEventHandler(selectionTester_SelectionChanged);
selectionTester.AddPoints(collectedPoints);
}
}
// Collect the stylus packets as the stylus moves.
protected override void OnStylusMove(StylusEventArgs e)
{
if (stylusPoints == null)
{
return;
}
StylusPointCollection collectedPoints = e.GetStylusPoints(this, stylusPoints.Description);
stylusPoints.Add(collectedPoints);
AddPointsToHitTester(collectedPoints);
}
protected override void OnMouseMove(MouseEventArgs e)
{
base.OnMouseMove(e);
if (e.StylusDevice != null)
{
return;
}
if (e.LeftButton == MouseButtonState.Released)
{
return;
}
stylusPoints ??= new StylusPointCollection();
Point pt = e.GetPosition(this);
StylusPointCollection collectedPoints = new StylusPointCollection(new Point[] { pt });
stylusPoints.Add(collectedPoints);
AddPointsToHitTester(collectedPoints);
}
private void AddPointsToHitTester(StylusPointCollection collectedPoints)
{
if (mode == InkMode.Select &&
selectionTester != null &&
selectionTester.IsValid)
{
// When the control is selecting strokes, add the
// stylus packetList to selectionTester.
selectionTester.AddPoints(collectedPoints);
}
}
// When the user lifts the stylus, create a Stroke from the
// collected stylus points and add it to the InkPresenter.
// When the control is selecting strokes, add the
// point data to the IncrementalHitTester.
protected override void OnStylusUp(StylusEventArgs e)
{
stylusPoints ??= new StylusPointCollection();
StylusPointCollection collectedPoints =
e.GetStylusPoints(this, stylusPoints.Description);
stylusPoints.Add(collectedPoints);
AddPointsToHitTester(collectedPoints);
AddStrokeToPresenter();
stylusPoints = null;
Stylus.Capture(null);
}
protected override void OnMouseLeftButtonUp(MouseButtonEventArgs e)
{
base.OnMouseLeftButtonUp(e);
if (e.StylusDevice != null) return;
if (stylusPoints == null) stylusPoints = new StylusPointCollection();
Point pt = e.GetPosition(this);
StylusPointCollection collectedPoints = new StylusPointCollection(new Point[] { pt });
stylusPoints.Add(collectedPoints);
AddPointsToHitTester(collectedPoints);
AddStrokeToPresenter();
stylusPoints = null;
Mouse.Capture(null);
}
private void AddStrokeToPresenter()
{
Stroke newStroke = new Stroke(stylusPoints);
if (mode == InkMode.Ink)
{
// Add the stroke to the InkPresenter.
newStroke.DrawingAttributes = inkDA.Clone();
presenter.Strokes.Add(newStroke);
}
if (mode == InkMode.Select && lassoPath == null)
{
// Add the lasso to the InkPresenter and add the packetList
// to selectionTester.
lassoPath = newStroke;
lassoPath.DrawingAttributes = selectDA.Clone();
presenter.Strokes.Add(lassoPath);
selectionTester.SelectionChanged -= new LassoSelectionChangedEventHandler
(selectionTester_SelectionChanged);
selectionTester.EndHitTesting();
}
}
void selectionTester_SelectionChanged(object sender,
LassoSelectionChangedEventArgs args)
{
// Change the color of all selected strokes to red.
foreach (Stroke selectedStroke in args.SelectedStrokes)
{
selectedStroke.DrawingAttributes.Color = Colors.Red;
selectedStrokes.Add(selectedStroke);
}
// Change the color of all unselected strokes to
// their original color.
foreach (Stroke unselectedStroke in args.DeselectedStrokes)
{
unselectedStroke.DrawingAttributes.Color = inkDA.Color;
selectedStrokes.Remove(unselectedStroke);
}
}
// Property to indicate whether the user is inputting or
// selecting ink.
public InkMode Mode
{
get
{
return mode;
}
set
{
mode = value;
// Set the DrawingAttributes of the DynamicRenderer
if (mode == InkMode.Ink)
{
renderer.DrawingAttributes = inkDA;
}
else
{
renderer.DrawingAttributes = selectDA;
}
// Reattach the visual of the DynamicRenderer to the InkPresenter.
presenter.DetachVisuals(renderer.RootVisual);
presenter.AttachVisuals(renderer.RootVisual, renderer.DrawingAttributes);
}
}
void DrawingAttributesChanged(object sender, PropertyDataChangedEventArgs e)
{
// Reattach the visual of the DynamicRenderer to the InkPresenter
// whenever the DrawingAttributes change.
presenter.DetachVisuals(renderer.RootVisual);
presenter.AttachVisuals(renderer.RootVisual, renderer.DrawingAttributes);
}
// Property to allow the user to change the pen's DrawingAttributes.
public DrawingAttributes InkDrawingAttributes
{
get
{
return inkDA;
}
}
// Property to allow the user to change the Selector'newStroke DrawingAttributes.
public DrawingAttributes SelectDrawingAttributes
{
get
{
return selectDA;
}
}
}
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Media
Imports System.Windows.Input
Imports System.Windows.Input.StylusPlugIns
Imports System.Windows.Ink
' Enum that keeps track of whether StrokeCollectionDemo is in ink mode
' or select mode.
Public Enum InkMode
Ink
[Select]
End Enum 'InkMode
' This control allows the user to input and select ink. When the
' user selects ink, the lasso remains visible until they erase, or clip
' the selected strokes, or clear the selection. When the control is
' in selection mode, strokes that are selected turn red.
Public Class InkSelector
Inherits Label
Private modeState As InkMode
Private inkDA As DrawingAttributes
Private selectDA As DrawingAttributes
Private presenter As InkPresenter
Private selectionTester As IncrementalLassoHitTester
Private selectedStrokes As New StrokeCollection()
' StylusPointCollection that collects the stylus points from the stylus events.
Private stylusPoints As StylusPointCollection
' Stroke that represents the lasso.
Private lassoPath As Stroke
Private renderer As DynamicRenderer
Public Sub New()
modeState = InkMode.Ink
' Use an InkPresenter to display the strokes on the custom control.
presenter = New InkPresenter()
Me.Content = presenter
' In the constructor.
' Selection drawing attributes use dark gray ink.
selectDA = New DrawingAttributes()
selectDA.Color = Colors.DarkGray
' ink drawing attributes use default attributes
inkDA = New DrawingAttributes()
inkDA.Width = 5
inkDA.Height = 5
AddHandler inkDA.AttributeChanged, _
AddressOf DrawingAttributesChanged
AddHandler selectDA.AttributeChanged, _
AddressOf DrawingAttributesChanged
' Add a DynmaicRenderer to the control so ink appears
' to "flow" from the tablet pen.
renderer = New DynamicRenderer()
renderer.DrawingAttributes = inkDA
Me.StylusPlugIns.Add(renderer)
presenter.AttachVisuals(renderer.RootVisual, _
renderer.DrawingAttributes)
End Sub
Shared Sub New()
' Allow ink to be drawn only within the bounds of the control.
Dim owner As Type = GetType(InkSelector)
ClipToBoundsProperty.OverrideMetadata(owner, _
New FrameworkPropertyMetadata(True))
End Sub
' Prepare to collect stylus packets. If Mode is set to Select,
' get the IncrementalHitTester from the InkPresenter'newStroke
' StrokeCollection and subscribe to its StrokeHitChanged event.
Protected Overrides Sub OnStylusDown(ByVal e As StylusDownEventArgs)
MyBase.OnStylusDown(e)
Stylus.Capture(Me)
' Create a new StylusPointCollection using the StylusPointDescription
' from the stylus points in the StylusDownEventArgs.
stylusPoints = New StylusPointCollection()
Dim eventPoints As StylusPointCollection = e.GetStylusPoints(Me, stylusPoints.Description)
stylusPoints.Add(eventPoints)
InitializeHitTester(eventPoints)
End Sub
Protected Overrides Sub OnMouseLeftButtonDown(ByVal e As MouseButtonEventArgs)
MyBase.OnMouseLeftButtonDown(e)
Mouse.Capture(Me)
If Not (e.StylusDevice Is Nothing) Then
Return
End If
Dim pt As Point = e.GetPosition(Me)
Dim collectedPoints As New StylusPointCollection(New Point() {pt})
stylusPoints = New StylusPointCollection()
stylusPoints.Add(collectedPoints)
InitializeHitTester(collectedPoints)
End Sub
Private Sub InitializeHitTester(ByVal collectedPoints As StylusPointCollection)
' Deselect any selected strokes.
Dim selectedStroke As Stroke
For Each selectedStroke In selectedStrokes
selectedStroke.DrawingAttributes.Color = inkDA.Color
Next selectedStroke
selectedStrokes.Clear()
If modeState = InkMode.Select Then
' Remove the previously drawn lasso, if it exists.
If Not (lassoPath Is Nothing) Then
presenter.Strokes.Remove(lassoPath)
lassoPath = Nothing
End If
selectionTester = presenter.Strokes.GetIncrementalLassoHitTester(80)
AddHandler selectionTester.SelectionChanged, AddressOf selectionTester_SelectionChanged
selectionTester.AddPoints(collectedPoints)
End If
End Sub
' Collect the stylus packets as the stylus moves.
Protected Overrides Sub OnStylusMove(ByVal e As StylusEventArgs)
If stylusPoints Is Nothing Then
Return
End If
Dim collectedPoints As StylusPointCollection = e.GetStylusPoints(Me, stylusPoints.Description)
stylusPoints.Add(collectedPoints)
AddPointsToHitTester(collectedPoints)
End Sub
Protected Overrides Sub OnMouseMove(ByVal e As MouseEventArgs)
MyBase.OnMouseMove(e)
If Not (e.StylusDevice Is Nothing) Then
Return
End If
If e.LeftButton = MouseButtonState.Released Then
Return
End If
If stylusPoints Is Nothing Then
stylusPoints = New StylusPointCollection()
End If
Dim pt As Point = e.GetPosition(Me)
Dim collectedPoints As New StylusPointCollection(New Point() {pt})
stylusPoints.Add(collectedPoints)
AddPointsToHitTester(collectedPoints)
End Sub
Private Sub AddPointsToHitTester(ByVal collectedPoints As StylusPointCollection)
If modeState = InkMode.Select AndAlso _
Not selectionTester Is Nothing AndAlso _
selectionTester.IsValid Then
' When the control is selecting strokes, add the
' stylus packetList to selectionTester.
selectionTester.AddPoints(collectedPoints)
End If
End Sub
' When the user lifts the stylus, create a Stroke from the
' collected stylus points and add it to the InkPresenter.
' When the control is selecting strokes, add the
' point data to the IncrementalHitTester.
Protected Overrides Sub OnStylusUp(ByVal e As StylusEventArgs)
If stylusPoints Is Nothing Then
stylusPoints = New StylusPointCollection()
End If
Dim collectedPoints As StylusPointCollection = _
e.GetStylusPoints(Me, stylusPoints.Description)
stylusPoints.Add(collectedPoints)
AddPointsToHitTester(collectedPoints)
AddStrokeToPresenter()
stylusPoints = Nothing
Stylus.Capture(Nothing)
End Sub
Protected Overrides Sub OnMouseLeftButtonUp(ByVal e As MouseButtonEventArgs)
MyBase.OnMouseLeftButtonUp(e)
If Not (e.StylusDevice Is Nothing) Then
Return
End If
If stylusPoints Is Nothing Then
stylusPoints = New StylusPointCollection()
End If
Dim pt As Point = e.GetPosition(Me)
Dim collectedPoints As New StylusPointCollection(New Point() {pt})
stylusPoints.Add(collectedPoints)
AddPointsToHitTester(collectedPoints)
AddStrokeToPresenter()
stylusPoints = Nothing
Mouse.Capture(Nothing)
End Sub
Private Sub AddStrokeToPresenter()
Dim newStroke As New Stroke(stylusPoints)
If modeState = InkMode.Ink Then
' Add the stroke to the InkPresenter.
newStroke.DrawingAttributes = inkDA.Clone()
presenter.Strokes.Add(newStroke)
End If
If modeState = InkMode.Select AndAlso lassoPath Is Nothing Then
' Add the lasso to the InkPresenter and add the packetList
' to selectionTester.
lassoPath = newStroke
lassoPath.DrawingAttributes = selectDA.Clone()
presenter.Strokes.Add(lassoPath)
RemoveHandler selectionTester.SelectionChanged, _
AddressOf selectionTester_SelectionChanged
selectionTester.EndHitTesting()
End If
End Sub
Private Sub selectionTester_SelectionChanged(ByVal sender As Object, _
ByVal args As LassoSelectionChangedEventArgs)
' Change the color of all selected strokes to red.
Dim selectedStroke As Stroke
For Each selectedStroke In args.SelectedStrokes
selectedStroke.DrawingAttributes.Color = Colors.Red
selectedStrokes.Add(selectedStroke)
Next selectedStroke
' Change the color of all unselected strokes to
' their original color.
Dim unselectedStroke As Stroke
For Each unselectedStroke In args.DeselectedStrokes
unselectedStroke.DrawingAttributes.Color = inkDA.Color
selectedStrokes.Remove(unselectedStroke)
Next unselectedStroke
End Sub
' Property to indicate whether the user is inputting or
' selecting ink.
Public Property Mode() As InkMode
Get
Return Mode
End Get
Set(ByVal value As InkMode)
modeState = value
' Set the DrawingAttributes of the DynamicRenderer
If modeState = InkMode.Ink Then
renderer.DrawingAttributes = inkDA
Else
renderer.DrawingAttributes = selectDA
End If
' Reattach the visual of the DynamicRenderer to the InkPresenter.
presenter.DetachVisuals(renderer.RootVisual)
presenter.AttachVisuals(renderer.RootVisual, renderer.DrawingAttributes)
End Set
End Property
Private Sub DrawingAttributesChanged(ByVal sender As Object, _
ByVal e As PropertyDataChangedEventArgs)
' Reattach the visual of the DynamicRenderer to the InkPresenter
' whenever the DrawingAttributes change.
presenter.DetachVisuals(renderer.RootVisual)
presenter.AttachVisuals(renderer.RootVisual, _
renderer.DrawingAttributes)
End Sub
' Property to allow the user to change the pen's DrawingAttributes.
Public ReadOnly Property InkDrawingAttributes() As DrawingAttributes
Get
Return inkDA
End Get
End Property
' Property to allow the user to change the Selector'newStroke DrawingAttributes.
Public ReadOnly Property SelectDrawingAttributes() As DrawingAttributes
Get
Return selectDA
End Get
End Property
End Class
Vea también
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