IXRVisualTransition::SetFrom (Compact 2013)

项目
04/19/2017

3/28/2014

This method sets the name of the visual state to transition from.

Syntax

virtual HRESULT STDMETHODCALLTYPE SetFrom(
    __in const WCHAR* pFrom
) = 0;

Parameters

pFrom
[in] Pointer to a string that identifies the name of the visual state to transition from.

Return Value

Returns an HRESULT that indicates success or failure.

Remarks

You can design the appearance of visual states in control templates and in user controls.

Visual states are predefined in the templates of controls that meet the following criteria:

Controls that derive from the IXRControl class.
Controls that do not derive from the IXRUserControl class.

Examples of templates that have states already defined are the IXRButton and IXRTextBox controls. You cannot add or remove states to a control template; you can only define the appearance of those states and define the transition behavior between states.

The following list shows examples of visual states of control templates that can be specified in the pFrom parameter. The availability of the following states depends upon the control:

Checked
Disabled
Focused
Indeterminate
MouseOver
Normal
Pressed
Unchecked
Unfocused

If you are working with states that you defined for a user control (a control that derives from the IXRUserControl class), you specify the name of your state in the pFrom parameter.

Specifying a state to transition from, by calling this method, is optional. A visual transition can be restricted to apply to only certain states, or it can be applied any time that the control transitions between states. You restrict when an IXRVisualTransition object is applied to the control by calling IXRVisualTransition::SetTo and IXRVisualTransition::SetFrom.

The following table describes the levels of restriction, from most restrictive to least restrictive.

Type of restriction	Value to set in SetFrom	Value to set in SetTo
From a specified state to another specified state	The Name of an IXRVisualState	The Name of an IXRVisualState
From any state to a specified state	Not set	The Name of an IXRVisualState
From a specified state to any state	The Name of an IXRVisualState	Not set
From any state to any other state	Not set	Note set

You can have multiple IXRVisualTransition objects in a collection that belongs to an IXRVisualStateGroup that refer to the same state. However, they will be used in the order that this table specifies.

You can define the To, From, and GeneratedDuration properties of a visual transition in Microsoft Silverlight 3 XAML, in the source XAML that is parsed by your application. For information about the differences between XAML in XAML for Windows Embedded and Silverlight 3, see Differences Between Microsoft Silverlight 3 and XAML for Windows Embedded. For more information about how to define this element in the source XAML for your application, see the VisualTransition.To Property and the VisualTransition Class on MSDN.

Note

The contents of a ControlTemplate defined in Microsoft Silverlight 3 XAML cannot be accessed from C++. Therefore, visual transitions and visual-state groups that were defined in a ControlTemplate in the source XAML for your application cannot be accessed in XAML for Windows Embedded object tree.

.NET Framework Equivalent

System.Windows.VisualTransition.From

Requirements

Header	XamlRuntime.h
sysgen	SYSGEN_XAML_RUNTIME

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