Como: Usar o elemento Imagem
This example shows how to include images in an application by using the Image element.
Exemplo
The following example shows how to render an image 200 pixels wide. In this Extensible Application Markup Language (XAML) example, both attribute syntax and property tag syntax are used to define the image. For more information on attribute syntax and property syntax, see Visão geral sobre propriedades de dependência. A BitmapImage is used to define the image's source data and is explicitly defined for the property tag syntax example. In addition, the DecodePixelWidth of the BitmapImage is set to the same width as the Width of the Image. This is done to ensure that the minimum amount of memory is used rendering the image.
Observação
In general, if you want to specify the size of a rendered image, specify only the Width or the Height but not both.If you only specify one, the image's aspect ratio is preserved.Otherwise, the image may unexpectedly appear stretched or warped.To control the image's stretching behavior, use the Stretch and StretchDirection properties.
Observação
When you specify the size of an image with either Width or Height, you should also set either DecodePixelWidth or DecodePixelHeight to the same respective size.
The Stretch property determines how the image source is stretched to fill the image element. For more information, see the Stretch enumeration.
<!-- Simple image rendering. However, rendering an image this way may not
result in the best use of application memory. See markup below which
creates the same end result but using less memory. -->
<Image Width="200"
Source="C:\Documents and Settings\All Users\Documents\My Pictures\Sample Pictures\Water Lilies.jpg"/>
<Image Width="200">
<Image.Source>
<!-- To save significant application memory, set the DecodePixelWidth or
DecodePixelHeight of the BitmapImage value of the image source to the desired
height and 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, only set either DecodePixelWidth
or DecodePixelHeight but not both. -->
<BitmapImage DecodePixelWidth="200"
UriSource="C:\Documents and Settings\All Users\Documents\My Pictures\Sample Pictures\Water Lilies.jpg" />
</Image.Source>
</Image>
The following example shows how to render an image 200 pixels wide using code.
Observação
Setting BitmapImage properties must be done within a BeginInit and EndInit block.
' Create Image Element
Dim myImage As New Image()
myImage.Width = 200
' Create source
Dim myBitmapImage As New BitmapImage()
' BitmapImage.UriSource must be in a BeginInit/EndInit block
myBitmapImage.BeginInit()
myBitmapImage.UriSource = New Uri("C:\Documents and Settings\All Users\Documents\My Pictures\Sample Pictures\Water Lilies.jpg")
' 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()
'set image source
myImage.Source = myBitmapImage
// Create Image Element
Image myImage = new Image();
myImage.Width = 200;
// Create source
BitmapImage myBitmapImage = new BitmapImage();
// BitmapImage.UriSource must be in a BeginInit/EndInit block
myBitmapImage.BeginInit();
myBitmapImage.UriSource = new Uri(@"C:\Documents and Settings\All Users\Documents\My Pictures\Sample Pictures\Water Lilies.jpg");
// 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();
//set image source
myImage.Source = myBitmapImage;