CroppedBitmap.BeginInit Methode
Definitie
Belangrijk
Bepaalde informatie heeft betrekking op een voorlopige productversie die aanzienlijk kan worden gewijzigd voordat deze wordt uitgebracht. Microsoft biedt geen enkele expliciete of impliciete garanties met betrekking tot de informatie die hier wordt verstrekt.
Geeft het begin van de CroppedBitmap initialisatie aan.
public:
virtual void BeginInit();public void BeginInit();abstract member BeginInit : unit -> unit
override this.BeginInit : unit -> unitPublic Sub BeginInit ()Implementeringen
Uitzonderingen
Het CroppedBitmap wordt momenteel geïnitialiseerd. BeginInit() is al gebeld.
– of –
De CroppedBitmap is al geïnitialiseerd.
Voorbeelden
In het volgende voorbeeld ziet u hoe u een CroppedBitmap met een set eigenschappen initialiseert met behulp van de BeginInit en EndInit methoden.
using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Media.Imaging;
namespace SDKSample
{
public partial class CroppedBitmapExample : Page
{
public CroppedBitmapExample()
{
///// Create a BitmapImage and set it's DecodePixelWidth to 200. Use /////
///// this BitmapImage as a source for other BitmapSource objects. /////
BitmapImage myBitmapImage = new BitmapImage();
// BitmapSource objects like BitmapImage can only have their properties
// changed within a BeginInit/EndInit block.
myBitmapImage.BeginInit();
myBitmapImage.UriSource = new Uri(@"sampleImages/WaterLilies.jpg",UriKind.Relative);
// To save significant application memory, set the DecodePixelWidth or
// DecodePixelHeight of the BitmapImage value of the image source to the desired
// height or width of the rendered image. If you don't do this, the application will
// cache the image as though it were rendered as its normal size rather then just
// the size that is displayed.
// Note: In order to preserve aspect ratio, set DecodePixelWidth
// or DecodePixelHeight but not both.
myBitmapImage.DecodePixelWidth = 200;
myBitmapImage.EndInit();
////////// Crop the BitmapSource ////////////
// Use the BitmapImage created above as the source for a new BitmapSource object
// which is cropped.
// Note: New BitmapSource does not cache. It is always pulled when required.
CroppedBitmap myCroppedBitmap = new CroppedBitmap();
// BitmapSource objects like CroppedBitmap can only have their properties
// changed within a BeginInit/EndInit block.
myCroppedBitmap.BeginInit();
// Use the BitmapSource object defined above as the source for this new
// BitmapSource (chain the BitmapSource objects together).
myCroppedBitmap.Source = myBitmapImage;
// Crop the image to the rectangular area defined below.
// The image is cropped to 80 pixels less in width and 60 less
// in height then the original source.
myCroppedBitmap.SourceRect = new Int32Rect(0,0,(int)myBitmapImage.Width-80, (int)myBitmapImage.Height-60);
myCroppedBitmap.EndInit();
// Create Image Element
Image myImage = new Image();
myImage.Width = 200;
//set image source
myImage.Source = myCroppedBitmap;
// Add Image to the UI
StackPanel myStackPanel = new StackPanel();
myStackPanel.Children.Add(myImage);
this.Content = myStackPanel;
}
}
}
Imports System.Windows
Imports System.Windows.Controls
Imports System.Windows.Media
Imports System.Windows.Media.Imaging
Namespace SDKSample
Class CroppedBitmapExample
Inherits Page
Public Sub New()
'/// Create a BitmapImage and set it's DecodePixelWidth to 200. Use /////
'/// this BitmapImage as a source for other BitmapSource objects. /////
Dim myBitmapImage As New BitmapImage()
' BitmapSource objects like BitmapImage can only have their properties
' changed within a BeginInit/EndInit block.
myBitmapImage.BeginInit()
myBitmapImage.UriSource = New Uri("sampleImages/WaterLilies.jpg", UriKind.Relative)
' To save significant application memory, set the DecodePixelWidth or
' DecodePixelHeight of the BitmapImage value of the image source to the desired
' height or width of the rendered image. If you don't do this, the application will
' cache the image as though it were rendered as its normal size rather then just
' the size that is displayed.
' Note: In order to preserve aspect ratio, set DecodePixelWidth
' or DecodePixelHeight but not both.
myBitmapImage.DecodePixelWidth = 200
myBitmapImage.EndInit()
'//////// Crop the BitmapSource ////////////
' Use the BitmapImage created above as the source for a new BitmapSource object
' which is cropped.
' Note: New BitmapSource does not cache. It is always pulled when required.
Dim myCroppedBitmap As New CroppedBitmap()
' BitmapSource objects like CroppedBitmap can only have their properties
' changed within a BeginInit/EndInit block.
myCroppedBitmap.BeginInit()
' Use the BitmapSource object defined above as the source for this new
' BitmapSource (chain the BitmapSource objects together).
myCroppedBitmap.Source = myBitmapImage
' Crop the image to the rectangular area defined below.
' The image is cropped to 80 pixels less in width and 60 less
' in height then the original source.
myCroppedBitmap.SourceRect = New Int32Rect(0, 0, _
CType(myBitmapImage.Width - 80, Integer), _
CType(myBitmapImage.Height - 60, Integer))
myCroppedBitmap.EndInit()
' Create Image Element
Dim myImage As New Image()
myImage.Width = 200
'set image source
myImage.Source = myCroppedBitmap
' Add Image to the UI
Dim myStackPanel As New StackPanel()
myStackPanel.Children.Add(myImage)
Me.Content = myStackPanel
End Sub
End Class
End Namespace 'ImagingSnippetGallery
Opmerkingen
Initialisatie van eigenschappen moet worden uitgevoerd tussen BeginInit en EndInit aanroepen. Zodra de CroppedBitmap eigenschap is geïnitialiseerd, worden eigenschapswijzigingen genegeerd.
