Tham khảo sách 'javascript bible_ chapter 18', công nghệ thông tin, kỹ thuật lập trình phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Image and Area Objects For users of Navigator 3 Internet Explorer 4 and later browsers images and areas those items created by the IMG and AREA tags are first-class objects that can be scripted for enhanced interactivity. The space reserved for an IMG tag can be refreshed with other images of the same size perhaps to show the highlighting of an icon button when the cursor rolls atop it. And with scriptable client-side area maps pages can be smarter about how users clicks on image regions respond. One further benefit afforded scripters is that images can be preloaded into the browser s image cache as the page loads. Therefore if you intend to swap images in response to user action no delay occurs in making the first swap The image is already in the image cache ready to go. In This Chapter How to precache images Swapping images after a document has loaded Creating interactive client-side image maps Image Object Properties Methods Event Handlers border None onAbort complete onError height onLoad hspace lowsrc name src vspace width x y 354 Part III JavaScript Object and Language Reference Syntax Creating an image IMG SRC ImageURL LOWSRC LowResImageURL NAME ImageName HEIGHT PixelCount PercentageValue WIDTH PixelCount PercentageValue hSPACE PixelCount vSPACE PixelCount BORDER PixelCount ALIGN left right top absmiddle absbottom texttop middle baseline bottom ISMAP USEMAP AreaMapName onLoad handlerTextOrFunction onAbort handlerTextOrFunction onError handlerTextOrFunction BODY imageName new Image pixelWidth pixelHeight Accessing image properties or methods window. . property method parameters window. index . property method parameters Nav2 Nav3 Nav4 IE3 J1 IE3 J2 IE4 J3 Compatibility 4 4 4 4 About this object Images have been in the HTML vocabulary since the earliest days but Netscape Navigator 3 was the first to treat them like first-class JavaScript objects. Internet Explorer 3 for the Macintosh includes a partial implementation of the .
