LinearGradientBrush Class
.NET Framework 4
Paints an area with a linear gradient.
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
The LinearGradientBrush type exposes the following members.
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LinearGradientBrush() | Initializes a new instance of the LinearGradientBrush class. |
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LinearGradientBrush(GradientStopCollection) | Initializes a new instance of the LinearGradientBrush class that has the specified gradient stops. |
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LinearGradientBrush(GradientStopCollection, Double) | Initializes a new instance of the LinearGradientBrush class that has the specified GradientStopCollection and angle. |
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LinearGradientBrush(Color, Color, Double) | Initializes a new instance of the LinearGradientBrush class that has the specified start Color, end Color, and angle. |
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LinearGradientBrush(GradientStopCollection, Point, Point) | Initializes a new instance of the LinearGradientBrush class that has the specified gradient stops, StartPoint, and EndPoint. |
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LinearGradientBrush(Color, Color, Point, Point) | Initializes a new instance of the LinearGradientBrush class that has the specified start Color, end Color, StartPoint, and EndPoint. |
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CanFreeze | Gets a value that indicates whether the object can be made unmodifiable. (Inherited from Freezable.) |
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ColorInterpolationMode | Gets or sets a ColorInterpolationMode enumeration that specifies how the gradient's colors are interpolated. (Inherited from GradientBrush.) |
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DependencyObjectType | Gets the DependencyObjectType that wraps the CLR type of this instance. (Inherited from DependencyObject.) |
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Dispatcher | Gets the Dispatcher this DispatcherObject is associated with. (Inherited from DispatcherObject.) |
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EndPoint | Gets or sets the ending two-dimensional coordinates of the linear gradient. |
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GradientStops | Gets or sets the brush's gradient stops. (Inherited from GradientBrush.) |
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HasAnimatedProperties | Gets a value that indicates whether one or more AnimationClock objects is associated with any of this object's dependency properties. (Inherited from Animatable.) |
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IsFrozen | Gets a value that indicates whether the object is currently modifiable. (Inherited from Freezable.) |
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IsSealed | Gets a value that indicates whether this instance is currently sealed (read-only). (Inherited from DependencyObject.) |
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MappingMode | Gets or sets a BrushMappingMode enumeration that specifies whether the gradient brush's positioning coordinates are absolute or relative to the output area. (Inherited from GradientBrush.) |
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Opacity | Gets or sets the degree of opacity of a Brush. (Inherited from Brush.) |
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RelativeTransform | Gets or sets the transformation that is applied to the brush using relative coordinates. (Inherited from Brush.) |
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SpreadMethod | Gets or sets the type of spread method that specifies how to draw a gradient that starts or ends inside the bounds of the object to be painted. (Inherited from GradientBrush.) |
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StartPoint | Gets or sets the starting two-dimensional coordinates of the linear gradient. |
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Transform | Gets or sets the transformation that is applied to the brush. This transformation is applied after the brush's output has been mapped and positioned. (Inherited from Brush.) |
| Name | Description | |
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ApplyAnimationClock(DependencyProperty, AnimationClock) | Applies an AnimationClock to the specified DependencyProperty. If the property is already animated, the SnapshotAndReplace handoff behavior is used. (Inherited from Animatable.) |
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ApplyAnimationClock(DependencyProperty, AnimationClock, HandoffBehavior) | Applies an AnimationClock to the specified DependencyProperty. If the property is already animated, the specified HandoffBehavior is used. (Inherited from Animatable.) |
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BeginAnimation(DependencyProperty, AnimationTimeline) | Applies an animation to the specified DependencyProperty. The animation is started when the next frame is rendered. If the specified property is already animated, the SnapshotAndReplace handoff behavior is used. (Inherited from Animatable.) |
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BeginAnimation(DependencyProperty, AnimationTimeline, HandoffBehavior) | Applies an animation to the specified DependencyProperty. The animation is started when the next frame is rendered. If the specified property is already animated, the specified HandoffBehavior is used. (Inherited from Animatable.) |
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CheckAccess | Determines whether the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.) |
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ClearValue(DependencyProperty) | Clears the local value of a property. The property to be cleared is specified by a DependencyProperty identifier. (Inherited from DependencyObject.) |
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ClearValue(DependencyPropertyKey) | Clears the local value of a read-only property. The property to be cleared is specified by a DependencyPropertyKey. (Inherited from DependencyObject.) |
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Clone | Creates a modifiable clone of this LinearGradientBrush, making deep copies of this object's values. When copying dependency properties, this method copies resource references and data bindings (but they might no longer resolve) but not animations or their current values. |
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CloneCore | Makes the instance a clone (deep copy) of the specified Freezable using base (non-animated) property values. (Inherited from Freezable.) |
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CloneCurrentValue | Creates a modifiable clone of this LinearGradientBrush object, making deep copies of this object's current values. Resource references, data bindings, and animations are not copied, but their current values are. |
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CloneCurrentValueCore | Makes the instance a modifiable clone (deep copy) of the specified Freezable using current property values. (Inherited from Freezable.) |
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CoerceValue | Coerces the value of the specified dependency property. This is accomplished by invoking any CoerceValueCallback function specified in property metadata for the dependency property as it exists on the calling DependencyObject. (Inherited from DependencyObject.) |
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CreateInstance | Initializes a new instance of the Freezable class. (Inherited from Freezable.) |
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CreateInstanceCore | When implemented in a derived class, creates a new instance of the Freezable derived class. (Inherited from Freezable.) |
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Equals | Determines whether a provided DependencyObject is equivalent to the current DependencyObject. (Inherited from DependencyObject.) |
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Finalize | Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.) |
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Freeze() | Makes the current object unmodifiable and sets its IsFrozen property to true. (Inherited from Freezable.) |
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FreezeCore | Makes this Animatable object unmodifiable or determines whether it can be made unmodifiable. (Inherited from Animatable.) |
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GetAnimationBaseValue | Returns the non-animated value of the specified DependencyProperty. (Inherited from Animatable.) |
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GetAsFrozen | Creates a frozen copy of the Freezable, using base (non-animated) property values. Because the copy is frozen, any frozen sub-objects are copied by reference. (Inherited from Freezable.) |
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GetAsFrozenCore | Makes the instance a frozen clone of the specified Freezable using base (non-animated) property values. (Inherited from Freezable.) |
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GetCurrentValueAsFrozen | Creates a frozen copy of the Freezable using current property values. Because the copy is frozen, any frozen sub-objects are copied by reference. (Inherited from Freezable.) |
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GetCurrentValueAsFrozenCore | Makes the current instance a frozen clone of the specified Freezable. If the object has animated dependency properties, their current animated values are copied. (Inherited from Freezable.) |
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GetHashCode | Gets a hash code for this DependencyObject. (Inherited from DependencyObject.) |
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GetLocalValueEnumerator | Creates a specialized enumerator for determining which dependency properties have locally set values on this DependencyObject. (Inherited from DependencyObject.) |
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GetType | Gets the Type of the current instance. (Inherited from Object.) |
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GetValue | Returns the current effective value of a dependency property on this instance of a DependencyObject. (Inherited from DependencyObject.) |
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InvalidateProperty | Re-evaluates the effective value for the specified dependency property (Inherited from DependencyObject.) |
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MemberwiseClone | Creates a shallow copy of the current Object. (Inherited from Object.) |
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OnChanged | Called when the current Freezable object is modified. (Inherited from Freezable.) |
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OnFreezablePropertyChanged(DependencyObject, DependencyObject) | Ensures that appropriate context pointers are established for a DependencyObjectType data member that has just been set. (Inherited from Freezable.) |
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OnFreezablePropertyChanged(DependencyObject, DependencyObject, DependencyProperty) | This member supports the Windows Presentation Foundation (WPF) infrastructure and is not intended to be used directly from your code. (Inherited from Freezable.) |
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OnPropertyChanged | Overrides the DependencyObject implementation of OnPropertyChanged to also invoke any Changed handlers in response to a changing dependency property of type Freezable. (Inherited from Freezable.) |
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ReadLocalValue | Returns the local value of a dependency property, if it exists. (Inherited from DependencyObject.) |
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ReadPreamble | Ensures that the Freezable is being accessed from a valid thread. Inheritors of Freezable must call this method at the beginning of any API that reads data members that are not dependency properties. (Inherited from Freezable.) |
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SetCurrentValue | Sets the value of a dependency property without changing its value source. (Inherited from DependencyObject.) |
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SetValue(DependencyProperty, Object) | Sets the local value of a dependency property, specified by its dependency property identifier. (Inherited from DependencyObject.) |
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SetValue(DependencyPropertyKey, Object) | Sets the local value of a read-only dependency property, specified by the DependencyPropertyKey identifier of the dependency property. (Inherited from DependencyObject.) |
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ShouldSerializeProperty | Returns a value that indicates whether serialization processes should serialize the value for the provided dependency property. (Inherited from DependencyObject.) |
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ToString() | Return string representation of this Brush. (Inherited from Brush.) |
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ToString(IFormatProvider) | Creates a string representation of this object based on the specified culture-specific formatting information. (Inherited from Brush.) |
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VerifyAccess | Enforces that the calling thread has access to this DispatcherObject. (Inherited from DispatcherObject.) |
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WritePostscript | Raises the Changed event for the Freezable and invokes its OnChanged method. Classes that derive from Freezable should call this method at the end of any API that modifies class members that are not stored as dependency properties. (Inherited from Freezable.) |
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WritePreamble | Verifies that the Freezable is not frozen and that it is being accessed from a valid threading context. Freezable inheritors should call this method at the beginning of any API that writes to data members that are not dependency properties. (Inherited from Freezable.) |
| Name | Description | |
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EndPointProperty | Identifies the EndPoint dependency property. |
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StartPointProperty | Identifies the StartPoint dependency property. |
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IFormattable.ToString | Formats the value of the current instance using the specified format. (Inherited from Brush.) |
A LinearGradientBrush paints an area with a linear gradient. A linear gradient defines a gradient along a line. The line's end points are defined by the StartPoint and EndPoint properties of the linear gradient. A LinearGradientBrush brush paints its GradientStops along this line.
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 painted, and its EndPoint is (1,1), the lower-right corner of the area being painted. The colors in the resulting gradient are interpolated along the diagonal path.
The following illustration shows a diagonal gradient. A line was added to highlight the interpolation path of the gradient from the start point to the end point.
A diagonal linear gradient
The next illustration shows the same linear gradient, but with highlighted gradient stops.
A diagonal linear gradient with highlighted gradient stops
It is possible to specify a gradient axis that does not completely fill area being painted. When this occurs, the SpreadMethod property determines how the remaining area is painted.
Freezable Features
A LinearGradientBrush is a type of Freezable object and therefore can be frozen to improve performance. For information about Freezable features, such as freezing and cloning, see Freezable Objects Overview.
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.
<!-- 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.
<!-- 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.
<!-- 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
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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 change 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.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
