LinearGradientBrush.StartPoint Property (System.Windows.Media)

.NET Framework Class Library

LinearGradientBrush..::.StartPoint Property

Gets or sets the starting two-dimensional coordinates of the linear gradient. This is a dependency property.

Namespace: System.Windows.Media
Assembly: PresentationCore (in PresentationCore.dll)
XMLNS for XAML: http://schemas.microsoft.com/winfx/2006/xaml/presentation, http://schemas.microsoft.com/netfx/2007/xaml/presentation

Syntax

Visual Basic (Declaration)

Public Property StartPoint As Point

Visual Basic (Usage)

Dim instance As LinearGradientBrush
Dim value As Point

value = instance.StartPoint

instance.StartPoint = value

public Point StartPoint { get; set; }

Visual C++

public:
property Point StartPoint {
    Point get ();
    void set (Point value);
}

JScript

public function get StartPoint () : Point
public function set StartPoint (value : Point)

XAML Property Element Usage

<object>
  <object.StartPoint>
    <Point .../>
  </object.StartPoint>
</object>

XAML Attribute Usage

<object StartPoint="Point" .../>

Property Value

Type: System.Windows..::.Point
The starting two-dimensional coordinates for the linear gradient. The default is (0, 0). This is a dependency property.

Dependency Property Information

Identifier field	StartPointProperty
Metadata properties set to true	None

Remarks

A LinearGradientBrush paints a gradient along a line. The line's start and end points are defined by the StartPoint and EndPoint properties of the LinearGradientBrush.

The default linear gradient is diagonal. In the default, the StartPoint of a linear gradient is (0,0), the upper-left corner of the area being filled, and its EndPoint is (1,1), the lower-right corner of the area being filled. The colors in the resulting gradient are interpolated along the diagonal path.

The following image shows a diagonal gradient. The black line was added to highlight the interpolation path of the gradient from the start point to the end point.

A diagonal linear gradient

Specifying Relative or Absolute Values

Note that the MappingMode property of a LinearGradientBrush determines whether its StartPoint is interpreted as a relative or absolute value. A MappingMode of RelativeToBoundingBox specifies that the EndPoint value is relative to the size of the painted area. A MappingMode of Absolute specifies that the StartPoint value is expressed in device independent pixels. By default, the MappingMode is set to RelativeToBoundingBox, making the StartPoint a relative value.

Examples

This example shows how to use the LinearGradientBrush class to paint an area with a linear gradient. In the following example, the Fill of a Rectangle is painted with a diagonal linear gradient that transitions from yellow to red to blue to lime green.

XAML

<!-- This rectangle is painted with a diagonal linear gradient. -->
<Rectangle Width="200" Height="100">
  <Rectangle.Fill>
    <LinearGradientBrush StartPoint="0,0" EndPoint="1,1">
      <GradientStop Color="Yellow" Offset="0.0" />
      <GradientStop Color="Red" Offset="0.25" />
      <GradientStop Color="Blue" Offset="0.75" />
      <GradientStop Color="LimeGreen" Offset="1.0" />
    </LinearGradientBrush>
  </Rectangle.Fill>
</Rectangle>

Rectangle diagonalFillRectangle = new Rectangle();
diagonalFillRectangle.Width = 200;
diagonalFillRectangle.Height = 100;

// Create a diagonal linear gradient with four stops.   
LinearGradientBrush myLinearGradientBrush =
    new LinearGradientBrush();
myLinearGradientBrush.StartPoint = new Point(0,0);
myLinearGradientBrush.EndPoint = new Point(1,1);
myLinearGradientBrush.GradientStops.Add(
    new GradientStop(Colors.Yellow, 0.0));
myLinearGradientBrush.GradientStops.Add(
    new GradientStop(Colors.Red, 0.25));                
myLinearGradientBrush.GradientStops.Add(
    new GradientStop(Colors.Blue, 0.75));        
myLinearGradientBrush.GradientStops.Add(
    new GradientStop(Colors.LimeGreen, 1.0));

// Use the brush to paint the rectangle.
diagonalFillRectangle.Fill = myLinearGradientBrush;

The following illustration shows the gradient created by the previous example.

To create a horizontal linear gradient, change the StartPoint and EndPoint of the LinearGradientBrush to (0,0.5) and (1,0.5). In the following example, a Rectangle is painted with a horizontal linear gradient.

XAML

<!-- This rectangle is painted with a horizontal linear gradient. -->
<Rectangle Width="200" Height="100">
  <Rectangle.Fill>
    <LinearGradientBrush StartPoint="0,0.5" EndPoint="1,0.5">
      <GradientStop Color="Yellow" Offset="0.0" />
      <GradientStop Color="Red" Offset="0.25" />
      <GradientStop Color="Blue" Offset="0.75" />
      <GradientStop Color="LimeGreen" Offset="1.0" />
    </LinearGradientBrush>
  </Rectangle.Fill>
</Rectangle>

Rectangle horizontalFillRectangle = new Rectangle();
horizontalFillRectangle.Width = 200;
horizontalFillRectangle.Height = 100;

// Create a horizontal linear gradient with four stops.   
LinearGradientBrush myHorizontalGradient =
    new LinearGradientBrush();
myHorizontalGradient.StartPoint = new Point(0,0.5);
myHorizontalGradient.EndPoint = new Point(1,0.5);
myHorizontalGradient.GradientStops.Add(
    new GradientStop(Colors.Yellow, 0.0));
myHorizontalGradient.GradientStops.Add(
    new GradientStop(Colors.Red, 0.25));                
myHorizontalGradient.GradientStops.Add(
    new GradientStop(Colors.Blue, 0.75));        
myHorizontalGradient.GradientStops.Add(
    new GradientStop(Colors.LimeGreen, 1.0));

// Use the brush to paint the rectangle.
horizontalFillRectangle.Fill = myHorizontalGradient;

The following illustration shows the gradient created by the previous example.

To create a vertical linear gradient, change the StartPoint and EndPoint of the LinearGradientBrush to (0.5,0) and (0.5,1). In the following example, a Rectangle is painted with a vertical linear gradient.

XAML

<!-- This rectangle is painted with a vertical gradient. -->
<Rectangle Width="200" Height="100">
  <Rectangle.Fill>
    <LinearGradientBrush StartPoint="0.5,0" EndPoint="0.5,1">
      <GradientStop Color="Yellow" Offset="0.0" />
      <GradientStop Color="Red" Offset="0.25" />
      <GradientStop Color="Blue" Offset="0.75" />
      <GradientStop Color="LimeGreen" Offset="1.0" />
    </LinearGradientBrush>
  </Rectangle.Fill>
</Rectangle>

Rectangle verticalFillRectangle = new Rectangle();
verticalFillRectangle.Width = 200;
verticalFillRectangle.Height = 100;

// Create a vertical linear gradient with four stops.   
LinearGradientBrush myVerticalGradient =
    new LinearGradientBrush();
myVerticalGradient.StartPoint = new Point(0.5,0);
myVerticalGradient.EndPoint = new Point(0.5,1);
myVerticalGradient.GradientStops.Add(
    new GradientStop(Colors.Yellow, 0.0));
myVerticalGradient.GradientStops.Add(
    new GradientStop(Colors.Red, 0.25));                
myVerticalGradient.GradientStops.Add(
    new GradientStop(Colors.Blue, 0.75));        
myVerticalGradient.GradientStops.Add(
    new GradientStop(Colors.LimeGreen, 1.0));

// Use the brush to paint the rectangle.
verticalFillRectangle.Fill = myVerticalGradient;

The following illustration shows the gradient created by the previous example.

Note:
The examples in this topic use the default coordinate system for setting start points and end points. The default coordinate system is relative to a bounding box: 0 indicates 0 percent of the bounding box , and 1 indicates 100 percent of the bounding box. You can c hange this coordinate system by setting the MappingMode property to the value BrushMappingMode..::.Absolute. An absolute coordinate system is not relative to a bounding box. Values are interpreted directly in local space.

Note:

The examples in this topic use the default coordinate system for setting start points and end points. The default coordinate system is relative to a bounding box: 0 indicates 0 percent of the bounding box , and 1 indicates 100 percent of the bounding box. You can c hange this coordinate system by setting the MappingMode property to the value BrushMappingMode..::.Absolute. An absolute coordinate system is not relative to a bounding box. Values are interpreted directly in local space.

For additional examples, see Brushes Sample. For more information about gradients and other types of brushes, see Painting with Solid Colors and Gradients Overview.

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information

.NET Framework

Supported in: 3.5, 3.0

Reference

LinearGradientBrush Class

LinearGradientBrush Members

System.Windows.Media Namespace

RadialGradientBrush

Other Resources

Painting with Solid Colors and Gradients Overview