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diff --git a/files/zh-tw/web/api/document/scroll_event/index.html b/files/zh-tw/web/api/document/scroll_event/index.html new file mode 100644 index 0000000000..26dbb7640c --- /dev/null +++ b/files/zh-tw/web/api/document/scroll_event/index.html @@ -0,0 +1,103 @@ +--- +title: scroll +slug: Web/API/Document/scroll_event +translation_of: Web/API/Document/scroll_event +--- +<p>當文件的可視區或元素被滾動(scroll),<code>scroll</code>事件會被觸發</p> + +<h2 id="一般資訊">一般資訊</h2> + +<dl> + <dt style="float: left; text-align: right; width: 120px;">規範</dt> + <dd style="margin: 0 0 0 120px;"><a class="external" href="http://www.w3.org/TR/DOM-Level-3-Events/#event-type-scroll">DOM L3</a>, <a href="http://www.w3.org/TR/cssom-view/#scrolling-0">CSSOM View</a></dd> + <dt style="float: left; text-align: right; width: 120px;">介面</dt> + <dd style="margin: 0 0 0 120px;">UIEvent</dd> + <dt style="float: left; text-align: right; width: 120px;">Bubbles</dt> + <dd style="margin: 0 0 0 120px;">Not on elements, but bubbles to the default view when fired on the document</dd> + <dt style="float: left; text-align: right; width: 120px;">Cancelable</dt> + <dd style="margin: 0 0 0 120px;">No</dd> + <dt style="float: left; text-align: right; width: 120px;">Target</dt> + <dd style="margin: 0 0 0 120px;">defaultView, Document, Element</dd> + <dt style="float: left; text-align: right; width: 120px;">Default Action</dt> + <dd style="margin: 0 0 0 120px;">None</dd> +</dl> + +<h2 id="屬性">屬性</h2> + +<table class="standard-table"> + <thead> + <tr> + <th scope="col">Property</th> + <th scope="col">Type</th> + <th scope="col">Description</th> + </tr> + </thead> + <tbody> + <tr> + <td><code>target</code> {{readonlyInline}}</td> + <td><a href="/en-US/docs/Web/API/EventTarget" title="EventTarget is an interface implemented by objects that can receive events and may have listeners for them."><code>EventTarget</code></a></td> + <td>The event target (the topmost target in the DOM tree).</td> + </tr> + <tr> + <td><code>type</code> {{readonlyInline}}</td> + <td><a href="/en-US/docs/Web/API/DOMString" title="DOMString is a UTF-16 String. As JavaScript already uses such strings, DOMString is mapped directly to a String."><code>DOMString</code></a></td> + <td>The type of event.</td> + </tr> + <tr> + <td><code>bubbles</code> {{readonlyInline}}</td> + <td><a href="/en-US/docs/Web/API/Boolean" title="The Boolean object is an object wrapper for a boolean value."><code>Boolean</code></a></td> + <td>Whether the event normally bubbles or not.</td> + </tr> + <tr> + <td><code>cancelable</code> {{readonlyInline}}</td> + <td><a href="/en-US/docs/Web/API/Boolean" title="The Boolean object is an object wrapper for a boolean value."><code>Boolean</code></a></td> + <td>Whether the event is cancellable or not.</td> + </tr> + <tr> + <td><code>view</code> {{readonlyInline}}</td> + <td><a class="new" href="/en-US/docs/Web/API/WindowProxy" rel="nofollow" title="The documentation about this has not yet been written; please consider contributing!"><code>WindowProxy</code></a></td> + <td><a href="/en-US/docs/Web/API/Document/defaultView" title="In browsers, document.defaultView returns the window object associated with a document, or null if none is available."><code>document.defaultView</code></a> (<code>window</code> of the document)</td> + </tr> + <tr> + <td><code>detail</code> {{readonlyInline}}</td> + <td><code>long</code> (<code>float</code>)</td> + <td>0.</td> + </tr> + </tbody> +</table> + +<h2 id="Example">Example</h2> + +<p>因為 <code>scroll</code> 事件是高頻觸發,這樣的事件處理程式不該進行運算成本高的程式,像是DOM的修改。所以,建議使用 <a href="/en-US/docs/DOM/window.requestAnimationFrame" title="/en-US/docs/DOM/window.requestAnimationFrame">requestAnimationFrame</a>, <a href="/en-US/docs/Web/API/WindowTimers/setTimeout">setTimeout</a> 或 <a href="/en-US/docs/Web/API/CustomEvent">customEvent</a> 如下所示</p> + +<h4 id="Scroll_optimization_with_window.requestAnimationFrame">Scroll optimization with window.requestAnimationFrame</h4> + +<pre class="brush: js">// Reference: http://www.html5rocks.com/en/tutorials/speed/animations/ + +var last_known_scroll_position = 0; +var ticking = false; + +function doSomething(scroll_pos) { + // do something with the scroll position +} + +window.addEventListener('scroll', function(e) { + last_known_scroll_position = window.scrollY; + if (!ticking) { + window.requestAnimationFrame(function() { + doSomething(last_known_scroll_position); + ticking = false; + }); + } + ticking = true; +});</pre> + +<p> </p> + +<p>關於<a href="/en-US/docs/Web/Events/resize#Example">resize</a>事件的更多類似例子。</p> + +<h2 id="瀏覽器相容性">瀏覽器相容性</h2> + +<h3 id="iOS_UIWebView">iOS UIWebView</h3> + +<p>在iOS UIWebViews中,滾動捲軸時 <code>scroll </code>事件不會觸發;它們要等到滾動完成時才被觸發。請參閱<a href="https://github.com/twbs/bootstrap/issues/16202">Bootstrap issue #16202</a>。 Safari 和 WKWebViews 不受此bug的影響。</p> |
