Επεξεργασία

Κοινή χρήση μέσω

TileBrush.Viewbox Property

  • Reference

Definition

Namespace:
System.Windows.Media
Assembly:
PresentationCore.dll

Gets or sets the position and dimensions of the content in a TileBrush tile.

public:
 property System::Windows::Rect Viewbox { System::Windows::Rect get(); void set(System::Windows::Rect value); };
public System.Windows.Rect Viewbox { get; set; }
member this.Viewbox : System.Windows.Rect with get, set
Public Property Viewbox As Rect

Property Value

Rect

The position and dimensions of the TileBrush content. The default value is a rectangle (Rect) that has a TopLeft of (0,0), and a Width and Height of 1.

Examples

You can specify the size and position of TileBrush content by using the Viewbox property. The ViewboxUnits property determines whether the Viewbox value is relative to the bounds of the TileBrush content or whether it is an absolute value.

The first illustration shows a 100 by 100 pixel image and then uses this image to show the effects of different Viewbox property settings.

An image Beginning sample image (100 by 100 device independent pixels)

The following illustration shows the output of a TileBrush that uses a Viewbox of 0.0,0.0, 0.25,0.5. Other relevant property values include the following:

This illustration shows several different Stretch property settings. The Stretch property determines how a TileBrush stretches its Viewbox to fill its Viewport.

TileBrush with a Viewbox of 0,0 0.25,0.5 TileBrush with a relative Viewbox of 0.0,0.0, 0.25,0.5

The next illustration shows a similar TileBrush but with a relative Viewbox of 0.5,0.25, 0.25,0.5.

TileBrush with a Viewbox of 0.5,0.25 0.25,0.5 Similar TileBrush but with a different Viewbox setting

The next illustration shows the same TileBrush but with a relative Viewport value of 0.0,0.0, 0.5,0.5 and a TileMode of Tile.

TiledTileBrush with a Viewbox of 0.5,0.25 0.25,0.5 Similar TileBrush but with tiling and a different Viewport setting

The following example shows how to create a tiled TileBrush that has a Viewbox of 0.5,0.25, 0.25,0.5.

<Rectangle
 Width="100" Height="100">
  <Rectangle.Fill>
    <ImageBrush 
      ImageSource="sampleImages\testImage.gif"
      Viewbox="0.5,0.25, 0.25,0.5" 
      ViewboxUnits="RelativeToBoundingBox" 
      Viewport="0,0,0.5,0.5"
      ViewportUnits="RelativeToBoundingBox" 
      TileMode="Tile" 
      Stretch="Fill" 
      AlignmentX="Center"
      AlignmentY="Center"/>
  </Rectangle.Fill>
</Rectangle>

// Create a rectangle.
Rectangle myRectangle = new Rectangle();
myRectangle.Width = 100;
myRectangle.Height = 100;

// Load the image.
BitmapImage theImage = 
    new BitmapImage(
        new Uri("sampleImages\\testImage.gif", UriKind.Relative));   
ImageBrush myImageBrush = new ImageBrush(theImage);

myImageBrush.Viewbox = new Rect(0.5, 0.25, 0.25, 0.5);
myImageBrush.ViewboxUnits = BrushMappingMode.RelativeToBoundingBox;
myImageBrush.Viewport = new Rect(0,0,0.25,0.25);
myImageBrush.ViewportUnits = BrushMappingMode.RelativeToBoundingBox;
myImageBrush.TileMode = TileMode.Tile;
myImageBrush.Stretch = Stretch.Fill;
myImageBrush.AlignmentX = AlignmentX.Center;
myImageBrush.AlignmentY = AlignmentY.Center;

// Use the ImageBrush to paint the rectangle's background.
myRectangle.Fill = myImageBrush;

' Create a rectangle.
Dim myRectangle As New Rectangle()
myRectangle.Width = 100
myRectangle.Height = 100

' Load the image.
Dim theImage As New BitmapImage(New Uri("sampleImages\testImage.gif", UriKind.Relative))
Dim myImageBrush As New ImageBrush(theImage)
With myImageBrush
    .Viewbox = New Rect(0.5, 0.25, 0.25, 0.5)
    .ViewboxUnits = BrushMappingMode.RelativeToBoundingBox
    .Viewport = New Rect(0, 0, 0.25, 0.25)
    .ViewportUnits = BrushMappingMode.RelativeToBoundingBox
    .TileMode = TileMode.Tile
    .Stretch = Stretch.Fill
    .AlignmentX = AlignmentX.Center
    .AlignmentY = AlignmentY.Center
End With

' Use the ImageBrush to paint the rectangle's background.
myRectangle.Fill = myImageBrush

Remarks

When you paint an area by using a TileBrush, you use three components: content, tiles, and the output area. The Viewbox property specifies the size and position of TileBrush content. The following illustration shows how these three TileBrush components relate to each other.

TileBrush components TileBrush components

Components of a tiled TileBrush

The ViewboxUnits property determines whether the Viewbox value is interpreted as a relative or absolute value. By default, the ViewboxUnits property is set to RelativeToBoundingBox.

Viewbox Clipping

TileBrush contents are never clipped to the Viewbox. However, TileBrush contents are clipped to the edges of the Viewport, which sets the values for the base tile.

The following illustration shows the effect of different Stretch settings on a TileBrush that has a Viewbox that is smaller than its Viewport. The parts of the image that are outside the Viewbox are tinted gray.

TileBrush with different Stretch settings TileBrush with different Stretch settings

Dependency Property Information
Identifier field ViewboxProperty
Metadata properties set to true None

Applies to

See also