IUIAnimationVariableChangeHandler::OnValueChanged method (uianimation.h)

Article
02/22/2024

Handles events that occur when the value of an animation variable changes.

This method receives updates as DOUBLE values.
To receive updates as INT32 values, use the IUIAnimationVariableIntegerChangeHandler::OnIntegerValueChanged method.

Syntax

HRESULT OnValueChanged(
  [in] IUIAnimationStoryboard *storyboard,
  [in] IUIAnimationVariable   *variable,
  [in] DOUBLE                 newValue,
  [in] DOUBLE                 previousValue
);

Parameters

[in] storyboard

The storyboard that is animating the animation variable specified by the variable parameter.

[in] variable

The animation variable that has been updated.

[in] newValue

The new value of the animation variable.

[in] previousValue

The previous value of the animation variable.

Return value

If the method succeeds, it returns S_OK. Otherwise, it returns an HRESULT error code. See Windows Animation Error Codes for a list of error codes.

Remarks

By default, a call made in a callback method to any other animation method results in the call failing and returning UI_E_ILLEGAL_REENTRANCY. However, there are exceptions to this default. The following methods can be successfully called from OnValueChanged:

Requirements

Requirement	Value
Minimum supported client	Windows 7, Windows Vista and Platform Update for Windows Vista [desktop apps \| UWP apps]
Minimum supported server	None supported
Target Platform	Windows
Header	uianimation.h
DLL	UIAnimation.dll