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用纯Js在每个li上应用函数

loops javascript

esafwan · 技术社区 · 14 年前

我已经使用语音api完成了一个读取元素内容的函数,我有一个这样的新闻列表

<ul id="news">
    <li>
How Instagram Is Winning Gold at the 2012 Olympics [INFOGRAPHIC]
   </li><li>
      Flickr Photo of Insect Identified As Never-Before-Seen Species [VIDEO]
   </li><li>
      The Upside to the End of the Olympics [COMIC]
   </li><li>
      40 Digital Media Resources You May Have Missed
   </li><li>
      19 Resources to Improve Your Photo and Video Skills
   </li><li>
      Top 10 Twitter Pics of the Week
   </li><li>
      Can Employees Be Trusted to Work From Home? [INFOGRAPHIC]
   </li><li>
      Capture Ghosts at Foursquare Spots With âGhostbustersâ iOS Game
   </li><li>
      Dog Is Terrified of Low-Fat Lamb Jerky [VIDEO]
   </li><li>
      5 Tips to Take Food Photos Good Enough to Eat
   </li><li>
      The 10 Most Stunning Images of Mars in History
   </li><li>
      The Many Looks of Spiderman Over the Past 50 Years [INFOGRAPHIC]
   </li><li>
      Top Ten GIFs of the Week
   </li><li>
      Romney and Obama Both Called Their Veeps the âNext Presidentâ [VIDEO]
   </li><li>
      Paul Ryan Visited Facebook, Met Zuckerberg [PICS]
   </li><li>
      Romneyâs Logo Looks Like Toothpaste [PICS]
   </li><li>
      Paul Ryan, Romneyâs VP Pick, Has Sizable Online Presence
   </li><li>
      Get Back in Kitchen With This Specialized Recipe Site
   </li>

</ul>

现在我使用这个函数来朗读文本。

function speak() {
    //speechapi.speak(document.getElementById('start').innerHTML,"male");
    speechapi.speak(document.getElementById('start').innerHTML,"male");

}

我如何使它读每一个li,中间有一个小的间隔?我不想使用jquery之类的。但我做不到。

3 回复 | 直到 14 年前

Alex Kalicki 14 年前

以下是一种方法,每行之间延迟2秒:

var news = document.getElementById('news').getElementsByTagName('li');

var newsItem = 0;
var speechInterval = setInterval(function(){
    speechapi.speak(news[newsItem].innerHTML, "male");
    if (++newsItem === news.length){
        window.clearInterval(speechInterval);
    }
}â, 2000);

DEMO, inserting text in a <p> tag instead of speaking it

Musa 14 年前

怎么样

function speak() {
    var i = 0,
    li = document.getElementById('news').getElementsByTagName('li'),
    interval = setInterval(function(){
        if (i < li.lenght){
            speechapi.speak(li[i].innerHTML,"male");
            i++;
        }
        else{
            clearInterval(interval);
        }
    }, 5000);
}

https://developer.mozilla.org/en-US/docs/DOM/document.getElementsByTagName

https://developer.mozilla.org/en-US/docs/DOM/document.getElementById

https://developer.mozilla.org/en-US/docs/window.setInterval

https://developer.mozilla.org/en/DOM/window.clearInterval

HBP 14 年前

以下是我对这个问题的看法:

function speak() {
    var li = document.getElementById ('news').getElementsByTagName ('li')
      , i = 0;

    li = [].slice.call (li, 0);

    (function speakItem() {
      speechapi.speak(li[i++].innerHTML, "male");
      i < li.length && window.setTimeout (speakItem, 1000);
    }
}

这个 [].slice.call (li, 0) 将li元素的活动列表转换为简单的JS数组,从而实现更高效的处理。

每个项目都被阅读,然后,如果有更多的项目,在说出下一个项目之前,会开始1秒的间隔。这允许长项目和短项目之间有恒定的整数。