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Hack 33. Create a Slideshow in Access

Hack 33. Create a Slideshow in Access

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of.jpgfilessitinadirectory,asshowninFigure4-21.



Figure4-21.Picturefilesinadirectory



Notethatallthefilesdon'thavetobeinthe.jpgformat.You

alsocanuseothergraphicstypes,suchasbitmaps(.bmp)and

TIFF(.tif)files(thisisalsospecifiedinthecode).



4.7.2.TheFormDesign

Figure4-22showstheforminDesignmode.Itcontainsjusta

fewcontrols:somebuttons,acheckbox,andtheimagecontrol.

Theimagecontrolhasaninitialpicture,butthisisoverridden

astheslideshowruns.



Figure4-22.Thedesignoftheslideshowform



Asyoucansee,theusercaneitherrunanautomatedslideshow

ornavigatethroughthegraphicsmanually.TheNextand

Previousbuttonsallowtheusertomoveforwardandbackward

throughthegraphicswhilenotinanautomatedmode.These

buttonsjustcyclethroughaVBAcollectionofpathstothe

graphics,andtheusercanusethemtoupdatetheimage

control'sPictureproperty.

Thecheckboxisusedtosetthemode.Ifit'schecked,the

slideshowruns.Regardlessofwhethertheuserletsthe

graphicschangeautomatically,shemustpresstheStartbutton.

Thisisanicefeaturebecauseitgivestheusercontrolover

whentostarttheshow.Afterall,someonemightstillbegetting

popcorn!

However,becausethereisaStartbutton,itmakessenseto

alsohaveaStopbutton.ClickingtheStopbuttonmerely



changesthevalueofaBoolean-typepublicvariable,named

stop_show,fromfalsetotrue.



4.7.3.TheCode

Avitalpieceofthisapplicationistheuseoftheform'sOnTimer

event.Inthefollowingcode,notethattheTimerIntervalhasa

settingof2000.ThistellstheformtofireitsOnTimereventevery

twoseconds.Youcanchangethisvaluetoaccommodateother

intervals:

OptionCompareDatabase

Publicstop_showAsBoolean

PublicpixpathsAsCollection

PublicpixnumAsInteger

'

PrivateSubForm_Open(CancelAsInteger)

'

'setinitialproperties

'



Me.chkRunContinuous=False

Me.cmdNext.Enabled=False

Me.cmdPrevious.Enabled=False

EndSub

'

PrivateSubcmdStart_Click()

'

'readpathsofgraphicsintoacollection

'displaysthefirstgraphic

'



stop_show=False

IfMe.chkRunContinuous=FalseThen

Me.cmdNext.Enabled=True

Me.cmdPrevious.Enabled=True



EndIf

'replacewithyourpath!!

pix_path="C:\ProductPhotos"

Setpixpaths=NewCollection

Setfs=Application.FileSearch

Withfs

.LookIn=pix_path

.FileName="*.jpg"

If.Execute()>0Then



Fori=1To.foundfiles.Count

pixpaths.AddItem:=.foundfiles(i)

Nexti

Else



MsgBox"Nofilesfound!"

EndIf

EndWith

'loadfirstpix

Me.imgPixHolder.Picture=pixpaths(1)

pixnum=1

EndSub

'

PrivateSubcmdNext_Click()

'



'advancestothenextgraphic



'cyclesforwardthroughcollection

'

Ifpixnum=pixpaths.CountThen

pixnum=1

Else

pixnum=pixnum+1

EndIf

Me.imgPixHolder.Picture=pixpaths(pixnum)

EndSub

'















PrivateSubcmdPrevious_Click()

'

'displaysthepreviousgraphic

'cyclesbackwardthroughcollection

'



Ifpixnum=1Then

pixnum=pixpaths.Count

Else

pixnum=pixnum-1

EndIf





Me.imgPixHolder.Picture=pixpaths(pixnum)

EndSub



'



PrivateSubcmdStop_Click()



'



'setsglobalvariabletofalse



'disablesPreviousandNextbuttons



'



stop_show=True





Me.cmdNext.Enabled=False





Me.cmdPrevious.Enabled=False

EndSub



'



PrivateSubForm_Timer()



'



'ifthemodeistoruncontinuouslyandthe



'stopbuttonhasnotbeenclicked,thenkeepcycling





IfMe.chkRunContinuous=True_





Andstop_show=FalseThencmdNext_Click

EndSub



Thiscodemodulecontainsahandfulofroutines.Theform'sOpen

eventbuildsacollectionofpathstothegraphics,foundwithina



specifieddirectory.Thespecificdirectoryandgraphicsfiletype

arehardcoded.TheFileSearchobjectusesthesevaluestofind

thegraphicsfiles.Youcanexpandthistolookinmorethanone

directoryand/orformorethanonefiletype.Readuponthe

FileSearchobjectintheHelpsystemorontheInternetformore

information.

ThechkRunContinuouscheckboxdetermineshowthe

applicationwillrun.Ifitisunchecked,theNextandPrevious

buttonsareusedtonavigatethroughthegraphics.Whenthe

userclickseitherbutton,theindextothecollectionisincreased

ordecreased,andthePicturepropertyoftheimagecontrolis

updatedtotheparticularcollectionitem.

IftheuserchecksthechkRunContinuouscheckbox,theNext

andPreviousbuttonsaredisabled,andtheslideshowrunson

itsown.Thetimethatelapsesbetweeneachgraphicisbased

ontheTimerInterval.Theslideshowwillruncontinuouslyuntil

theuserclickstheStopbutton.WhentheStopbuttonis

clicked,itsetsthestop_showvariabletotrue.ThiscausestheTimer

eventtoskipupdatingthegraphicbecausetheupdateoccurs

onlywhenstop_showisfalse.



4.7.4.HackingtheHack

Youcanenhancethisbasicslideshowinseveralways.Onething

toconsideristhatthegraphicshavenosupportingtext.

Keepinganunboundapproach,onewayaroundthisproblemis

toprovideawaytodisplaydetailsaboutagraphicwhenitis

clicked.TheimagecontrolhasaClickevent,whichyoucanuse

toreturnthevalueofthePictureproperty,asshowninFigure423.



Figure4-23.Takingadvantageoftheimage

control'sClickevent



Becausethepicturebeingdisplayedcanprovideitsname,you

canusetheimagecontrol'sClickeventtofindanddisplay

anythingpertainingtotheparticulargraphic.Forexample,

becausethegraphic'sfilenamecanbeisolated,youcangather

additionalinformationaboutthegraphicfromatextfileorother

source.

Ofcourse,anotherapproachistosimplybindtheimagecontrol

topathsstoredinatable.Anotherfieldcanthensupplytextual

informationaboutthepictureinatextbox.Infact,thisisthe

morestandardapproach.Ididn'tpointthisoutearlierbecause

itrequiresmoreworktoupdatethepathsintablerecordsthan

justonceinthecode.Also,ifyouadaptthecodetoworkwitha

user-suppliedpath,ofcoursetheunboundapproachmakes

moresensebecausetherewouldbenopreenteredpaths.



Hack34.PlayVideosinAccessForms



Deliveryourmessagethemultimediawaywiththe

WindowsMediaPlayer.

Here'sareallyneatwaytospiceupyourAccessapplications:

playmovies!Althoughthismightseemalittletooentertaining

for"real"businessuse,considerthatmoviesareoneofthebest

vehiclesfordeliveringinformation.Youcanincorporatemovies

intoyourdatabasedesigninseveralways.Youcanrelatemovie

clipstodatarecords,inwhichcasetheassociatedmovieruns

whenarecordisdisplayed.Youcanalsohaveanunrelated

movieplayondemand(requiringabuttonclickorsomeother

waytoinitiatethemovietoplay).

Toplaymoviesyouneedtoincorporateacontrolthatcan

handlemoviefiles.Anumberoftheseareavailable,most

notablyWindowsMediaPlayer,whichiswhatthishackuses.



4.8.1.PuttingthePlayerontheForm

First,youmustaddWindowsMediaPlayertotheform.Because

thisisn'tastandardcontrol,youmustaccessitusingtheMore

Controlsbuttononthetoolbox,asshowninFigure4-24.

ClickingtheMoreControlsbuttondisplaysalengthylistof

controlsandlibraries.ScrolldowntofindWindowsMediaPlayer,

asshowninFigure4-25.

Afteryouclickthecontrolinthelist,drawitontheform.Figure

4-26showsaforminwhichWindowsMediaPlayer,alistbox,

andacommandbuttonhavebeeninserted.Inthis



configuration,thelistboxdisplaysalistofmoviesfromwhichto

select;clickingthebuttonplaystheselectedmovie.

InFigure4-26,thelistboxispopulatedwithpathsto.mpg

moviefiles.Thelistboxhastwocolumns.Thefirstcolumnisthe

boundcolumn,whichholdsthepathstothemoviefiles.Its

widthissettozero,soitisn'tdisplayedtotheuser.Instead,the

secondcolumn,whichcontainsfriendlynamesforthemovies,

isdisplayed.Whentheuserhasselectedamovie,shesimply

pressesthecommandbuttontostartthemovie.Thiseffectively

isasimpleplaylist.Figure4-27showstheforminViewmode

beforeplayingamovie.



Figure4-24.Lookingformorecontrols



Figure4-25.SelectingWindowsMediaPlayer



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Hack 33. Create a Slideshow in Access

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