WM HSCROLL

This message occurs when a horizontal scroll bar control has a significant event to notify to its owner.

Syntax

param1
    USHORT  usidentifier;  /* Scroll bar control window identifier. */

param2
    SHORT   sslider;       /* Slider position. */
    USHORT  uscmd;         /* Command. */

Parameters

usidentifier (USHORT) - input

Scroll bar control window identifier.

sslider (SHORT) - input

Slider position.

0: Either the operator is not moving the slider with the pointer device, or for the instance where uscmd is SB_SLIDERPOSITION the pointer is outside the tracking rectangle when the button is released.

Other: Slider position.

uscmd (USHORT) - input

Command.

SB_LINELEFT: Sent if the operator clicks on the left arrow of the scroll bar, or depresses the VK_LEFT key.

SB_LINERIGHT: Sent if the operator clicks on the right arrow of the scroll bar, or depresses the VK_RIGHT key.

SB_PAGELEFT: Sent if the operator clicks on the area to the left of the slider, or depresses the VK_PAGELEFT key.

SB_PAGERIGHT: Sent if the operator clicks on the area to the right of the slider, or depresses the VK_PAGERIGHT key.

SB_SLIDERPOSITION: Sent to indicate the final position of the slider.

SB_SLIDERTRACK: If the operator moves the scroll bar slider with the pointer device, this is sent every time the slider position changes.

SB_ENDSCROLL: Sent when the operator has finished scrolling, but only if the operator has not been doing any absolute slider positioning.

Returns

ulReserved (ULONG) - returns

Reserved value, should be 0.

Remarks

in Horizontal Scroll Bars

The scroll bar control window procedure generates this message and posts it to its owner, informing the owner of the event.

Default Processing

The default window procedure takes no action on this message, other than to set ulReserved to 0.

Related Messages

• WM_HSCROLL (in Horizontal Scroll Bars)