TrackBarCtrl Control

Purpose

Creates a track bar control in the current active form, window, or dialog.

Syntax

TrackBarCtrl text$, id%, x, y, w, h[, style%]

text$:control text
id%:control identifier
x,y,w,h:iexp
style%:the control styles

Description

A TrackBarCtrl is a window that contains a slider and optional tick marks. When the user moves the slider, using either the mouse or the direction keys, the trackbar sends notification messages to indicate the change.

A track bar notifies its parent window of user actions by sending the parent WM_HSCROLL or WM_VSCROLL messages that should be handled in the form's _MessageProc sub.

Example

Public Const TB_LINEUP = 0

Public Const TB_LINEDOWN = 1

Public Const TB_PAGEUP = 2

Public Const TB_PAGEDOWN = 3

Public Const TB_THUMBPOSITION = 4

Public Const TB_THUMBTRACK = 5

Public Const TB_TOP = 6

Public Const TB_BOTTOM = 7

Public Const TB_ENDTRACK = 8

Form frm

TrackBarCtrl "", 10, 20, 20, 150, 30

Global Handle hWndTrack = GetDlgItem(frm.hWnd, 10)

Sleep

Until Me Is Nothing

Sub frm_MessageProc(hWnd%, Mess%, wParam%, lParam%, retval%, ValidRet?)

Switch Mess

Case WM_HSCROLL, WM_VSCROLL

If lParam = hWndTrack

'Trace LoWord(wParam)

Switch LoWord(wParam) 'Notification Message (Reason, sent)

Case TB_BOTTOM 'VK_END

Case TB_ENDTRACK 'WM_KEYUP (the user released a key that sent a relevant virtual key code)

Case TB_LINEDOWN 'VK_RIGHT Or VK_DOWN

Case TB_LINEUP 'VK_LEFT Or VK_UP

Case TB_PAGEDOWN 'VK_NEXT (the user clicked the channel below or to the right of the slider)

Case TB_PAGEUP 'VK_PRIOR (the user clicked the channel above or to the left of the slider)

Case TB_THUMBPOSITION 'WM_LBUTTONUP following a TB_THUMBTRACK notification message

Case TB_THUMBTRACK 'Slider movement (the user dragged the slider)

Case TB_TOP 'VK_HOME

EndSwitch

EndIf

EndSwitch

EndSub

Remarks

This command is particular useful for a dialog box in a GLL, because a GLL doesn't support OCX controls.