How to: Use the Image Element
This example shows how to include images in an application using the Image element.
Example
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 Dependency Properties Overview. 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.
Note: In general, if you want to specify the size of a rendered image, specify only the Width or the Height but not both. By only specifying one, the image is allowed to preserve its aspect ratio. Otherwise the image may unexpectedly appear stretched or warped.
Performance Note: 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.
<!-- 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.
.gif) Note: |
|---|
Setting BitmapImage properties must be done within a BeginInit and EndInit block. |
// 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;
The following example shows how to render an image 200 pixels wide using code.
| Note: |
|---|
Setting or modifying BitmapImage properties must be done within a BeginInit and EndInit block. |
// 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;
The following example applies each of the available Stretch enumerations to an Image.
The following image shows the output from the example and demonstrates the affect the different Stretch settings have when applied to an image.
<Page xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml" >
<DockPanel>
<Border DockPanel.Dock="Top" Background="Black">
<TextBlock Foreground="White" HorizontalAlignment="Stretch" FontSize="20">
Stretching an Image
</TextBlock>
</Border>
<Grid Name="simpleGrid" Background="{StaticResource CheckeredBrushResource}"
Margin="10"
ShowGridLines="True"
VerticalAlignment="Center"
HorizontalAlignment="Center">
<Grid.ColumnDefinitions>
<ColumnDefinition Width="175" />
<ColumnDefinition Width="175" />
<ColumnDefinition Width="175" />
<ColumnDefinition Width="175" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition Height="200"/>
</Grid.RowDefinitions>
<!-- Labels -->
<TextBlock Style="{StaticResource Header1}"
Grid.Column="0" Grid.Row="0">None</TextBlock>
<TextBlock Style="{StaticResource Header1}"
Grid.Column="1" Grid.Row="0">Uniform</TextBlock>
<TextBlock Style="{StaticResource Header1}"
Grid.Column="2" Grid.Row="0">UniformToFill</TextBlock>
<TextBlock Style="{StaticResource Header1}"
Grid.Column="3" Grid.Row="0">Fill</TextBlock>
<Border Grid.Column="0" Grid.Row="1" BorderThickness="1" BorderBrush="Black">
<!-- None: Image is not scaled. If image is larger than the
output area, the image will be cropped to the size of the output area.-->
<Image
Source="sampleImages/gecko.jpg"
Stretch="None" />
</Border>
<Border Grid.Column="1" Grid.Row="1" BorderThickness="1" BorderBrush="Black">
<!-- Uniform: Scale to fit output area.
Aspect ratio is preserved.-->
<Image
Source="sampleImages/gecko.jpg"
Stretch="Uniform" />
</Border>
<Border Grid.Column="2" Grid.Row="1" BorderThickness="1" BorderBrush="Black">
<!-- UniformToFill: Scale to completely fill output area.
Aspect ratio is preserved. Cropping may occur.-->
<Image
Source="sampleImages/gecko.jpg"
Stretch="UniformToFill" />
</Border>
<Border Grid.Column="3" Grid.Row="1" BorderThickness="1" BorderBrush="Black">
<!-- Fill: Scale to completely fill output area.
Aspect ratio may not be preserved.-->
<Image
Source="sampleImages/gecko.jpg"
Stretch="Fill" />
</Border>
</Grid>
</DockPanel>
</Page>