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FMX.StdCtrls.TTrackBar.OnChange

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Delphi

property OnChange: TNotifyEvent read FOnChange write FOnChange;

C++

__property OnChange;

Properties

Type Visibility Source Unit Parent
event published
FMX.StdCtrls.pas
FMX.StdCtrls.hpp
FMX.StdCtrls TTrackBar

Description

Occurs immediately after the position of the slider of this track bar changes.

FMX.StdCtrls.TTrackBar.OnChange inherits from FMX.StdCtrls.TCustomTrack.OnChange. All content below this line refers to FMX.StdCtrls.TCustomTrack.OnChange.

Occurs immediately after the position of the slider of this track bar changes.

Write an OnChange event handler to provide additional functionality when changing the position of the slider of this track bar component.

The OnTracking is very similar to OnChange. The following table shows the difference in the behavior of these events in certain scenarios:

Tracking Scenario Behaviour Events fired IsTracking

True or False

Press an arrow key on the keyboard.

The Thumb moves for one "step".

  1. OnTracking
  2. OnChange

False

True

Click on the Thumb of the track bar and move the Thumb.

The Thumb moves as much as you move it.

For each "step" of the movement:

  1. OnTracking
  2. OnChange

True

False

Click on the Thumb of the track bar and move the Thumb.

The Thumb moves as much as you move it.

For each step of the movement:

After you release the Thumb

True

True

Click anywhere on the track bar (excluding the Thumb).

The Thumb moves for one "step".

  1. OnTracking
  2. OnChange

False

False

Click anywhere on the track bar (excluding the Thumb).

The Thumb moves to the position where you click.

  1. OnTracking
  2. OnChange

False

True or False

Hold the Shift button and click anywhere on the track bar (excluding the Thumb).

The Thumb moves to the position where you click.

  1. OnTracking
  2. OnChange

False

See Also

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