UIElement Class

public class UIElement : LogicalTreeNodeBase, IInputElement, IUIElement, ILogicalTreeNode, IDpiAwareElement, IDisposable

public UIElement()

Remarks

The default constructor initializes all fields to their default values.

[Browsable(false)]
public int ActualHeight { get; }

Property Value

int:

The actual height of the element.

Remarks

This is determined by the layout system after Arrange(Rectangle) has completed. This is only valid if IsArrangeValid is true.

[Browsable(false)]
public int ActualWidth { get; }

Property Value

int:

The actual width of the element.

Remarks

This is determined by the layout system after Arrange(Rectangle) has completed. This is only valid if IsArrangeValid is true.

[Browsable(false)]
public Rectangle Bounds { get; }

Property Value

Rectangle:

A Rectangle specifying the bounds of the element.

protected virtual bool CaptureMouseWhenPressed { get; }

Property Value

bool:

true if the mouse should automatically be captured when the element is pressed; otherwise, false.

[Browsable(false)]
public virtual Rectangle ClipBounds { get; }

Property Value

Rectangle:

A Rectangle specifying the clip bounds when drawing the element.

[Browsable(false)]
public Size DesiredSize { get; }

Property Value

Size:

The desired size of the element as computed by Measure(Graphics, Size).

Remarks

This is only valid if IsMeasureValid is true.

[Browsable(false)]
public SizeF DpiScaleFactor { get; }

Property Value

SizeF:

A SizeF where Width is applied to the x-axis, and Height is applied to the y-axis.

See Also

• DpiScaleChanged(SizeF)

protected virtual bool InvalidateOnMouseEvents { get; }

Property Value

bool:

true if the element should be invalidated when mouse events occur.

[Browsable(false)]
public bool IsArrangeValid { get; }

Property Value

bool:

true if the value of the DesiredSize property and position of child elements is valid; otherwise, false.

Remarks

A developer can force arrangement to be invalidated by calling InvalidateArrange(). IsArrangeValid and IsMeasureValid are related, in that arrangement cannot be valid without measurement first being valid.

[Browsable(false)]
public bool IsMeasureValid { get; }

Property Value

bool:

true if the value of the DesiredSize property is valid; otherwise, false.

Remarks

A developer can force arrangement to be invalidated by calling InvalidateMeasure(). IsArrangeValid and IsMeasureValid are related, in that arrangement cannot be valid without measurement first being valid.

[Browsable(false)]
public bool IsMouseCaptured { get; }

Property Value

bool:

true if the element is currently capturing the mouse; otherwise, false.

[Browsable(false)]
public bool IsRightToLeft { get; }

Property Value

bool:

true if the element is using a right-to-left layout; otherwise, false.

[Browsable(false)]
public Size Size { get; }

Property Value

Size:

The actual size of the element.

Remarks

This is determined by the layout system after Arrange(Rectangle) has completed. This is only valid if IsArrangeValid is true.

[Browsable(false)]
public Point VisualOffset { get; }

Property Value

Point:

The X/Y offset of the element relative to its parent element's coordinate system.

Remarks

This is determined by the layout system after Arrange(Rectangle) has completed. This is only valid if IsArrangeValid is true.

protected bool AddPendingGraphicsInversion(Rectangle bounds)

Parameter	Type	Description
bounds	Rectangle	A Rectangle specifying the bounds to invert.

Returns

bool:

true if the inversion operation was added successfully; otherwise, false.

protected bool AddPendingScrollOperation(Rectangle bounds, int xAmount, int yAmount)

Parameter	Type	Description
bounds	Rectangle	The bounds to scroll.
xAmount	int	The amount to scroll horizontally.
yAmount	int	The amount to scroll vertically.

Returns

bool:

true if the scroll operation was added successfully; otherwise, false.

protected bool AddPendingScrollOperation(Rectangle bounds, Orientation orientation, int amount)

Parameter	Type	Description
bounds	Rectangle	The bounds to scroll.
orientation	Orientation	The direction to scroll.
amount	int	The amount to scroll.

Returns

bool:

true if the scroll operation was added successfully; otherwise, false.

public void Arrange(Rectangle finalRect)

Parameter	Type	Description
finalRect	Rectangle	The final bounds of the element, relative to its parent.

Remarks

Override the ArrangeOverride(Size) method with custom arrange logic.

protected virtual Size ArrangeOverride(Size finalSize)

Parameter	Type	Description
finalSize	Size	The final area within the parent that this element should use to arrange itself and its children.

Returns

Size:

The actual size used.

Remarks

Element authors should override this method, call Arrange(Rectangle) on each visible child element and position each child element. It is required that a parent element calls Arrange(Rectangle) on each child or they won't be rendered.

public void CaptureMouse()

public virtual bool ContainsLocation(Point location)

Parameter	Type	Description
location	Point	The Point location to examine.

Returns

bool:

true if this element's bounds contains the specified location; otherwise, false.

Remarks

Override this method to prevent certain portions of the element's bounds from being included in hit-testing.

public Graphics CreateGraphics()

Returns

Graphics:

The Graphics object for the object.

protected override void Dispose(bool disposing)

Parameter	Type	Description
disposing	bool	Whether the object is being disposed.

public virtual void DpiScaleChanged(SizeF scaleFactor)

Parameter	Type	Description
scaleFactor	SizeF	The new scale factor where Width is applied to the x-axis, and Height is applied to the y-axis.

See Also

• DpiScaleFactor

public virtual Cursor GetCursor(Point point)

Parameter	Type	Description
point	Point	The Point to examine.

Returns

Cursor:

The Cursor that should be used when the mouse is over the element at the specified Point.

public void Invalidate()

public void Invalidate(InvalidationLevels levels, InvalidationTypes types)

Parameter	Type	Description
levels	InvalidationLevels	The hierarchy levels at which to invalidate.
types	InvalidationTypes	The types of invalidation to perform.

public void Invalidate(Rectangle rect)

Parameter	Type	Description
rect	Rectangle	The bounds of the rectangle to invalidate.

public void InvalidateArrange()

public void InvalidateMeasure()

public void Measure(Graphics g, Size availableSize)

Parameter	Type	Description
g	Graphics	The Graphics object to use for measurement.
availableSize	Size	The available size that this element can give to child elements. Infinity can be specified as a value to indicate that the element will size to whatever content is available.

Remarks

Override the MeasureOverride(Graphics, Size) method with custom measure logic.

protected virtual Size MeasureOverride(Graphics g, Size availableSize)

Parameter	Type	Description
g	Graphics	The Graphics object to use for measurement.
availableSize	Size	The available size that this element can give to child elements. Infinity can be specified as a value to indicate that the element will size to whatever content is available.

Returns

Size:

The size that this element determines it needs during layout, based on its calculations of child element sizes.

Remarks

Element authors should override this method, call Measure(Graphics, Size) on each visible child element and determine the total size required.

protected virtual void OnClick(MouseEventArgs e)

Parameter	Type	Description
e	MouseEventArgs	A MouseEventArgs that contains the event data.

protected virtual void OnDoubleClick(MouseEventArgs e)

Parameter	Type	Description
e	MouseEventArgs	A MouseEventArgs that contains the event data.

protected virtual void OnMouseCaptureLost(EventArgs e)

Parameter	Type	Description
e	EventArgs	The EventArgs that contains the event data.

protected virtual void OnMouseDown(MouseEventArgs e)

Parameter	Type	Description
e	MouseEventArgs	A MouseEventArgs that contains the event data.

protected virtual void OnMouseEnter(MouseEventArgs e)

Parameter	Type	Description
e	MouseEventArgs	A MouseEventArgs that contains the event data.

protected virtual void OnMouseHover(MouseEventArgs e)

Parameter	Type	Description
e	MouseEventArgs	A MouseEventArgs that contains the event data.

protected virtual void OnMouseLeave(MouseEventArgs e)

Parameter	Type	Description
e	MouseEventArgs	A MouseEventArgs that contains the event data.

protected virtual void OnMouseMove(MouseEventArgs e)

Parameter	Type	Description
e	MouseEventArgs	A MouseEventArgs that contains the event data.

protected virtual void OnMouseUp(MouseEventArgs e)

Parameter	Type	Description
e	MouseEventArgs	A MouseEventArgs that contains the event data.

protected virtual void OnMouseWheel(MouseEventArgs e)

Parameter	Type	Description
e	MouseEventArgs	A MouseEventArgs that contains the event data.

protected override void OnParentChanged()

protected virtual void OnRender(PaintEventArgs e)

Parameter	Type	Description
e	PaintEventArgs	A PaintEventArgs that contains the event data.

protected virtual void OnRenderChildElements(PaintEventArgs e)

Parameter	Type	Description
e	PaintEventArgs	A PaintEventArgs that contains the event data.

Remarks

This method should not generally be overridden. The default implementation of this method calls the Render(PaintEventArgs) method on all child elements.

protected virtual void OnResize(EventArgs e)

Parameter	Type	Description
e	EventArgs	An EventArgs that contains the event data.

protected virtual void PostArrangeOverride()

public void ReleaseMouseCapture()

public void Render(PaintEventArgs e)

Parameter	Type	Description
e	PaintEventArgs	A PaintEventArgs that contains the event data.

public GeneralTransform TransformToAncestor(IUIElement ancestor)

Parameter	Type	Description
ancestor	IUIElement	The ancestor IUIElement.

Returns

GeneralTransform:

A GeneralTransform from this element to a ancestor element.

public GeneralTransform TransformToDescendant(IUIElement descendant)

Parameter	Type	Description
descendant	IUIElement	The descendant IUIElement.

Returns

GeneralTransform:

A GeneralTransform from this element to a descendant element.

public virtual void UpdateLayout()

Remarks

This ensures that UIElement objects with invalid measure or arrange states will get a call to their Measure(Graphics, Size) and Arrange(Rectangle) methods, and all computed sizes will be validated. This method does nothing if layout is clean but it does work if layout is not clean so avoid calling it after each change in the element tree. It makes sense to either never call it (system will do this in a deferred manner) or only call it if you absolutely need updated sizes and positions after you do all changes.

public event MouseEventHandler Click

Event Type

MouseEventHandler

public event MouseEventHandler DoubleClick

Event Type

MouseEventHandler

public event EventHandler MouseCaptureLost

Event Type

EventHandler

public event MouseEventHandler MouseDown

Event Type

MouseEventHandler

public event MouseEventHandler MouseEnter

Event Type

MouseEventHandler

public event MouseEventHandler MouseHover

Event Type

MouseEventHandler

public event MouseEventHandler MouseLeave

Event Type

MouseEventHandler

public event MouseEventHandler MouseMove

Event Type

MouseEventHandler

public event MouseEventHandler MouseUp

Event Type

MouseEventHandler

public event MouseEventHandler MouseWheel

Event Type

MouseEventHandler

public event EventHandler Resize

Event Type

EventHandler

protected readonly Logger logger