DrawingContext.PushOpacity Metodo

Definizione

Spazio dei nomi:

System.Windows.Media

Assembly:

PresentationCore.dll

Inserisce l'impostazione di opacità specificata nel contesto del disegno.

Overload

PushOpacity(Double)	Inserisce l'impostazione di opacità specificata nel contesto del disegno.
PushOpacity(Double, AnimationClock)	Inserisce l'impostazione di opacità specificata nel contesto del disegno e applica il clock di animazione definito.

PushOpacity(Double)

Inserisce l'impostazione di opacità specificata nel contesto del disegno.

public:
 abstract void PushOpacity(double opacity);

public abstract void PushOpacity (double opacity);

abstract member PushOpacity : double -> unit

Public MustOverride Sub PushOpacity (opacity As Double)

Parametri

opacity

Double

Fattore di opacità da applicare ai comandi di disegno successivi. Questo fattore è cumulativo con le operazioni PushOpacity(Double) precedenti.

Esempio

Nell'esempio seguente vengono illustrati i PushOpacitycomandi , PushEffecte Pop .

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Navigation;
using System.Windows.Media.Effects;

namespace SDKSample
{

    public class PushEffectExample : Page
    {

        public PushEffectExample()
        {
            Pen shapeOutlinePen = new Pen(Brushes.Black, 2);
            shapeOutlinePen.Freeze();

            // Create a DrawingGroup
            DrawingGroup dGroup = new DrawingGroup();

            // Obtain a DrawingContext from 
            // the DrawingGroup.
            using (DrawingContext dc = dGroup.Open())
            {
                // Draw a rectangle at full opacity.
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, new Rect(0, 0, 25, 25));

                // Push an opacity change of 0.5. 
                // The opacity of each subsequent drawing will
                // will be multiplied by 0.5.
                dc.PushOpacity(0.5);

                // This rectangle is drawn at 50% opacity.
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, new Rect(25, 25, 25, 25));

                // Blurs subsquent drawings. 
                dc.PushEffect(new BlurBitmapEffect(), null);

                // This rectangle is blurred and drawn at 50% opacity (0.5 x 0.5). 
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, new Rect(50, 50, 25, 25));

                // This rectangle is also blurred and drawn at 50% opacity.
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, new Rect(75, 75, 25, 25));

                // Stop applying the blur to subsquent drawings.
                dc.Pop();

                // This rectangle is drawn at 50% opacity with no blur effect.
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, new Rect(100, 100, 25, 25));
            }

            // Display the drawing using an image control.
            Image theImage = new Image();
            DrawingImage dImageSource = new DrawingImage(dGroup);
            theImage.Source = dImageSource;

            this.Content = theImage;
        }
    }
}

Imports System.Windows.Media.Animation
Imports System.Windows.Media.Effects

Namespace SDKSample


    Public Class PushEffectExample
        Inherits Page

        Public Sub New()
            Dim shapeOutlinePen As New Pen(Brushes.Black, 2)
            shapeOutlinePen.Freeze()

            ' Create a DrawingGroup
            Dim dGroup As New DrawingGroup()

            ' Obtain a DrawingContext from 
            ' the DrawingGroup.
            Using dc As DrawingContext = dGroup.Open()
                ' Draw a rectangle at full opacity.
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, New Rect(0, 0, 25, 25))

                ' Push an opacity change of 0.5. 
                ' The opacity of each subsequent drawing will
                ' will be multiplied by 0.5.
                dc.PushOpacity(0.5)

                ' This rectangle is drawn at 50% opacity.
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, New Rect(25, 25, 25, 25))

                ' Blurs subsquent drawings. 
                dc.PushEffect(New BlurBitmapEffect(), Nothing)

                ' This rectangle is blurred and drawn at 50% opacity (0.5 x 0.5). 
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, New Rect(50, 50, 25, 25))

                ' This rectangle is also blurred and drawn at 50% opacity.
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, New Rect(75, 75, 25, 25))

                ' Stop applying the blur to subsquent drawings.
                dc.Pop()

                ' This rectangle is drawn at 50% opacity with no blur effect.
                dc.DrawRectangle(Brushes.Blue, shapeOutlinePen, New Rect(100, 100, 25, 25))
            End Using

            ' Display the drawing using an image control.
            Dim theImage As New Image()
            Dim dImageSource As New DrawingImage(dGroup)
            theImage.Source = dImageSource

            Me.Content = theImage

        End Sub




    End Class

End Namespace

Commenti

L'opacità viene combinata in tutti i comandi di disegno successivi fino a quando non viene rimossa dal Pop comando .

PushOpacity(Double, AnimationClock)

Inserisce l'impostazione di opacità specificata nel contesto del disegno e applica il clock di animazione definito.

public:
 abstract void PushOpacity(double opacity, System::Windows::Media::Animation::AnimationClock ^ opacityAnimations);

public abstract void PushOpacity (double opacity, System.Windows.Media.Animation.AnimationClock opacityAnimations);

abstract member PushOpacity : double * System.Windows.Media.Animation.AnimationClock -> unit

Public MustOverride Sub PushOpacity (opacity As Double, opacityAnimations As AnimationClock)

Parametri

opacity

Double

Fattore di opacità da applicare ai comandi di disegno successivi. Questo fattore è cumulativo con le operazioni PushOpacity(Double) precedenti.

opacityAnimations

AnimationClock

Clock con il quale aggiungere un'animazione al valore di opacità oppure null se non viene applicata alcuna animazione. È necessario creare il clock in base a un oggetto AnimationTimeline in grado di aggiungere un'animazione ai valori Double.

Commenti

L'opacità viene combinata in tutti i comandi di disegno successivi fino a quando non viene rimossa dal Pop comando .