JS 参考手册

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JavaScript

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HTML DOM

DOM Attributes DOM Document DOM Element DOM Events DOM Event 对象 DOM HTMLCollection DOM Location DOM Navigator DOM Screen DOM Style
alignContent alignItems alignSelf animation animationDelay animationDirection animationDuration animationFillMode animationIterationCount animationName animationTimingFunction animationPlayState background backgroundAttachment backgroundColor backgroundImage backgroundPosition backgroundRepeat backgroundClip backgroundOrigin backgroundSize backfaceVisibility border borderBottom borderBottomColor borderBottomLeftRadius borderBottomRightRadius borderBottomStyle borderBottomWidth borderCollapse borderColor borderImage borderImageOutset borderImageRepeat borderImageSlice borderImageSource borderImageWidth borderLeft borderLeftColor borderLeftStyle borderLeftWidth borderRadius borderRight borderRightColor borderRightStyle borderRightWidth borderSpacing borderStyle borderTop borderTopColor borderTopLeftRadius borderTopRightRadius borderTopStyle borderTopWidth borderWidth bottom boxShadow boxSizing captionSide caretColor clear clip color columnCount columnFill columnGap columnRule columnRuleColor columnRuleStyle columnRuleWidth columns columnSpan columnWidth counterIncrement counterReset cursor direction display emptyCells filter flex flexBasis flexDirection flexFlow flexGrow flexShrink flexWrap cssFloat font fontFamily fontSize fontStyle fontVariant fontWeight fontSizeAdjust height isolation justifyContent left letterSpacing lineHeight listStyle listStyleImage listStylePosition listStyleType margin marginBottom marginLeft marginRight marginTop maxHeight maxWidth minHeight minWidth objectFit objectPosition opacity order orphans outline outlineColor outlineOffset outlineStyle outlineWidth overflow overflowX overflowY padding paddingBottom paddingLeft paddingRight paddingTop pageBreakAfter pageBreakBefore pageBreakInside perspective perspectiveOrigin position quotes resize right scrollBehavior tableLayout tabSize textAlign textAlignLast textDecoration textDecorationColor textDecorationLine textDecorationStyle textIndent textOverflow textShadow textTransform top transform transformOrigin transformStyle transition transitionProperty transitionDuration transitionTimingFunction transitionDelay unicodeBidi userSelect verticalAlign visibility width wordBreak wordSpacing wordWrap widows zIndex
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HTML 对象

<a> <abbr> <address> <area> <article> <aside> <audio> <b> <base> <bdo> <blockquote> <body> <br> <button> <canvas> <caption> <cite> <code> <col> <colgroup> <datalist> <dd> <del> <details> <dfn> <dialog> <div> <dl> <dt> <em> <embed> <fieldset> <figcaption> <figure> <footer> <form> <head> <header> <h1> - <h6> <hr> <html> <i> <iframe> <img> <ins> <input> button <input> checkbox <input> color <input> date <input> datetime <input> datetime-local <input> email <input> file <input> hidden <input> image <input> month <input> number <input> password <input> radio <input> range <input> reset <input> search <input> submit <input> text <input> time <input> url <input> week <kbd> <label> <legend> <li> <link> <map> <mark> <menu> <menuitem> <meta> <meter> <nav> <object> <ol> <optgroup> <option> <output> <p> <param> <pre> <progress> <q> <s> <samp> <script> <section> <select> <small> <source> <span> <strong> <style> <sub> <summary> <sup> <table> <tbody> <td> <tfoot> <th> <thead> <tr> <textarea> <time> <title> <track> <u> <ul> <var> <video>

其他参考手册

CSSStyleDeclaration JS 类型转换


onload 事件

❮ DOM 事件 ❮ Event 对象

实例

在页面加载后立即执行 JavaScript:

<body onload="myFunction()">
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页面下方有更多实例。


定义和用法

onload 事件在对象被加载后发生。

onload 最常用于 <body> 元素中,用于在网页完全加载所有内容(包括图像、脚本文件、CSS 文件等)后执行脚本。

onload 事件可用于检查访问者的浏览器类型和浏览器版本,并根据这些信息加载网页的正确版本。

onload 事件也可用于处理 cookie (请参阅下面的更多实例).


浏览器支持

事件
onload Yes Yes Yes Yes Yes

语法

在 HTML 中:

<element onload="myScript">
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在 JavaScript 中:

object.onload = function(){myScript};
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在 JavaScript 中,使用 addEventListener() 方法:

object.addEventListener("load", myScript);
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注释: The addEventListener() method is not supported in Internet Explorer 8 and earlier versions.



技术细节

是否支持冒泡: No
是否支持取消: No
事件类型: 如果从用户界面生成,UiEvent。否则 Event
支持的 HTML 标签: <body>, <frame>, <iframe>, <img>, <input type="image">, <link>, <script>, <style>
DOM 版本: Level 2 Events

更多实例

实例

在 <img> 元素上使用 onload。加载图像后立即发出"图像已加载"的提醒:

<img src="w3javascript.gif" onload="loadImage()" width="100" height="132">

<script>
function loadImage() {
  alert("Image is loaded");
}
</script>
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实例

使用 onload 事件处理 cookie:

<body onload="checkCookies()">

<script>
function checkCookies() {
  var text = "";

  if (navigator.cookieEnabled == true) {
    text = "Cookies are enabled.";
  } else {
     text = "Cookies are not enabled.";
  }
  document.getElementById("demo").innerHTML = text;
}
</script>
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❮ DOM 事件 ❮ Event 对象