DIV教程之英文教程:用CSS把持和操纵BODY标志
不管你用什么工具软件制作网页，都有在有意无意地使用CSS。用好CSS能使你的网页更加简炼，同样内容的网页，有的人做出来有几十KB，而高手做出来只有十几KB。网页制造POLUOLUO文章简介：利用CSS利用你的body元素.
Let’ssayyouwanttochangethecolorofyourlinksonjustyourcontactpagetored.Theyareblueoneveryotherpage,butitjustmakessenseforthemtoberedonyourcontactpage(forsomereason).Thereareacouplewaysyoucouldgoaboutthis.
[*]Youcoulddeclareaseparatestylesheetforyourcontactpage.Thisisn’tideal,becauseit’sredundant.Ifyoumakeanyotherchanges,you’llalwayshavetomakethembothonthemainstylesheetandthecontactpagestylesheet.
[*]Youcouldgiveallthoselinksauniqueclassonthatpage.Thisisn’tideal,becauseitisn’tverysemanticandit’salsoredundant.Whyapplyaclasstoeverysinglelinkonthepagewhentheyreallyaren’tanydifferentfromlinkselsewhereonthesite,contextuallyspeaking?
[*]ThebestsolutionistogiveyourthebodyauniqueID.Thissolvestheproblemperfectly.YoucanusethesamestylesheetandtargetjustthelinksyouwanttowithasingleCSSselector.
Howit’sdone
Simple,literallyjustapplytheIDtothebodytag:
...</head><bodyid="contact-page">...Nowforourexampleofmakingalllinksonthecontactpageredinsteadofblue,justusesomeCSSlikethis:
a{color:blue;}#contact-pagea{color:red;}
Howaboutamorepracticalexample?
Yougotit.Oneofthemostusefulimplementationsofthistechniqueiswithinnavigation.Takealookatthissamplenavigation:
Seehowtheforumstabisthe“active”tab?Certainlythat’sjustaslightchangeinCSS,probablyjustashiftinthepositionofabackgroundimage.PerhapstheXHTMLlookssomethinglikethis:
...<li><ahref="/fieldtips">Fieldtips</a></li><liclass="active"><ahref="/forums">Forums</a></li>...The“active”classappliedtothelistitemiswhatshiftsthebackgroundimage.That’lldothetrick,butwhataboutwhenwemovetotheFieldTipspage?WewillhavetoremovetheactiveclassfromtheforumstabandapplyittothetheFieldTipstab.That’snotveryconvenient.Thatmeansthecodeforthenavigationblockisuniqueoneverysinglepageofthesite.Solet’ssaydowntheroadwewanttoaddaContacttab,we’llhavetoalterthecodeoneverysinglepage.Nofun.
Let’sdothisalittlesmarter.Firstwedon’twanttoincludethenavigationblockofcodeoneverypage,wewanttoincludeit,probablywithasimplePHPincludelikethis:
<?phpinclude_once("nav.html");?>
Butthenhowdoweapplythe“active”classtothecurrentnavigationlistelement?
ThisiswhereapplywhatwejustlearnedaboutgivinguniqueID’stothebody!Insteadofapplyingaclasstoonlytheactivelistelement,let’sapplyauniqueclasstoeachseparatelistitemaswellasgiveourbodyanuniqueID.
...</head><bodyid="field-tips">...<liclass="fieldtips"><ahref="/fieldtips">Fieldtips</a></li><liclass="forums"><ahref="/forums">Forums</a></li>...NowwecantargetspecificelementsinthenavigationwithsomecleverCSS:
#field-tipsli.fieldtips,#forumsli.forums{background-position:bottom;}Thismeansthatthecodeforthenavigationblockcanstaythesameoneverypage,yetonlythenavigationelementnativetothatpagewillbeaffectedbythisCSSand“flip”totheactivestate.
Let’sgetevenmoredynamic
ReaderBrianleftanawesomecommentonhowyoucanusePHPtoapplytheuniqueIDtotothebodyelement:
<bodyid="<?=basename(Let’ssayyouwanttochangethecolorofyourlinksonjustyourcontactpagetored.Theyareblueoneveryotherpage,butitjustmakessenseforthemtoberedonyourcontactpage(forsomereason).Thereareacouplewaysyoucouldgoaboutthis.
[*]Youcoulddeclareaseparatestylesheetforyourcontactpage.Thisisn’tideal,becauseit’sredundant.Ifyoumakeanyotherchanges,you’llalwayshavetomakethembothonthemainstylesheetandthecontactpagestylesheet.
[*]Youcouldgiveallthoselinksauniqueclassonthatpage.Thisisn’tideal,becauseitisn’tverysemanticandit’salsoredundant.Whyapplyaclasstoeverysinglelinkonthepagewhentheyreallyaren’tanydifferentfromlinkselsewhereonthesite,contextuallyspeaking?
[*]ThebestsolutionistogiveyourthebodyauniqueID.Thissolvestheproblemperfectly.YoucanusethesamestylesheetandtargetjustthelinksyouwanttowithasingleCSSselector.
Howit’sdone
Simple,literallyjustapplytheIDtothebodytag:
...</head><bodyid="contact-page">...Nowforourexampleofmakingalllinksonthecontactpageredinsteadofblue,justusesomeCSSlikethis:
a{color:blue;}#contact-pagea{color:red;}
Howaboutamorepracticalexample?
Yougotit.Oneofthemostusefulimplementationsofthistechniqueiswithinnavigation.Takealookatthissamplenavigation:
Seehowtheforumstabisthe“active”tab?Certainlythat’sjustaslightchangeinCSS,probablyjustashiftinthepositionofabackgroundimage.PerhapstheXHTMLlookssomethinglikethis:
...<li><ahref="/fieldtips">Fieldtips</a></li><liclass="active"><ahref="/forums">Forums</a></li>...The“active”classappliedtothelistitemiswhatshiftsthebackgroundimage.That’lldothetrick,butwhataboutwhenwemovetotheFieldTipspage?WewillhavetoremovetheactiveclassfromtheforumstabandapplyittothetheFieldTipstab.That’snotveryconvenient.Thatmeansthecodeforthenavigationblockisuniqueoneverysinglepageofthesite.Solet’ssaydowntheroadwewanttoaddaContacttab,we’llhavetoalterthecodeoneverysinglepage.Nofun.
Let’sdothisalittlesmarter.Firstwedon’twanttoincludethenavigationblockofcodeoneverypage,wewanttoincludeit,probablywithasimplePHPincludelikethis:
<?phpinclude_once("nav.html");?>
Butthenhowdoweapplythe“active”classtothecurrentnavigationlistelement?
ThisiswhereapplywhatwejustlearnedaboutgivinguniqueID’stothebody!Insteadofapplyingaclasstoonlytheactivelistelement,let’sapplyauniqueclasstoeachseparatelistitemaswellasgiveourbodyanuniqueID.
...</head><bodyid="field-tips">...<liclass="fieldtips"><ahref="/fieldtips">Fieldtips</a></li><liclass="forums"><ahref="/forums">Forums</a></li>...NowwecantargetspecificelementsinthenavigationwithsomecleverCSS:
#field-tipsli.fieldtips,#forumsli.forums{background-position:bottom;}Thismeansthatthecodeforthenavigationblockcanstaythesameoneverypage,yetonlythenavigationelementnativetothatpagewillbeaffectedbythisCSSand“flip”totheactivestate.
Let’sgetevenmoredynamic
ReaderBrianleftanawesomecommentonhowyoucanusePHPtoapplytheuniqueIDtotothebodyelement:
a{color:blue;}#contact-pagea{color:red;}2ThiswillreturnthenameofthePHPfilebeingexecutedastheID(e.g.bodyid=”index.php”).Toleaveoffthe.phppart,justremovethe“.php”part.
SERVER,".php")?>">ThiswillreturnthenameofthePHPfilebeingexecutedastheID(e.g.bodyid=”index.php”).Toleaveoffthe.phppart,justremovethe“.php”part.
提高易用性。使用CSS可以结构化HTML，例如：标签只用来控制段落，heading标签只用来控制标题，table标签只用来表现格式化的数据等等。 dreamweaver8中文版下载(dw)对专业网页图像设计的FIREWORKS，三者被MACROMEDIA公司称为DREAMTEAM(梦之队)。 还可以在Dreamweaver常用工具中选择超级链接，完成相应的填写即可。 不管老师做怎样的解释，而我却对它感到很是吃力，诸如里面有许多不知道的功能。 帧(frames)和表格的制作速度快的令您无法想像。进阶表格编辑功能使您简单的选择单格、行、栏或作未连续之选取。 Dreamweaver8中文版(dw)是由Macromedia公司开发的一款所见即所得的网页编辑器。和二维动画设计软件FLASH，专业网页图像设计软件FIREWORKS，并称为“网页三剑客”。 直接用代码建立链接，如：可以直接输入 <a herf = \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\"red.html\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\">红色的网页 12、插入标签法建立链接，可以再选中文字后在代码中插入html标签，页元素<a>.也可以按ctrl+t进入html标签插入方法之后输入代码即可。 每天上网看着那样多的网页，于是我才下定决心选择了网页制作这一门课程，目的就是希望以后能够做出一个完美的网页来。 Adobe Dreamweaver(前称Macromedia Dreamweaver)是Adobe公司的著名网站开发工具。
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