Question

我的下面的代码与我的文字与下一个＆amp;上一个按钮。我希望它在页面加载时重复循环，并在两者之间暂停一个按钮。所有三个按钮完全位于显示文本的同一行的右侧。请支持我..谢谢......

<!DOC HTML>
<html>
<head>
<script type="text/javascript">
var messages = [
    'Messages for <em>kindergarden</em> class',
    'Message for <em>1st grade</em>',
    'Message for <em>2nd grade</em>',
    'Message for <em>3rd grade</em>',
    'Message for <em>4th grade</em>',
    'Message for <em>5th grade</em>',
    'Message for <em>6th grade</em>'
];

var msgPtr = 0;
function nextMsg(direction) {
  msgPtr = msgPtr + direction;
  if (msgPtr < 0) { msgPtr = messages.length-1; }
  if (msgPtr > messages.length-1) { msgPtr = 0; }
  document.getElementById('msg').innerHTML = messages[msgPtr];
}
window.onload = function () {
  nextMsg(0);
}
</script>

<style type="text/css">
em { color:orange; }
#msg { 
font-family:monospace; 
background-color:yellow;
font-size:1em;  
width:890px; 
border:1px dotted red; 
overflow:hidden;}
</style>

</head>
<body>
<div id="msg"></div><br>
<button onclick="nextMsg(-1)">&lt;</button>
<button onclick="nextMsg(-1)">||</button>
<button onclick="nextMsg(1)">&gt;</button>
</body>
</html>

Answer 1

一种解决方案是以递归方式调用nextMsg（），如

function nextMsg(direction){
    //snip
    nextMsg(direction);
}

我用jQuery写了一个非常快速的概念证明，应该以更清晰的方式重写： http://jsfiddle.net/5NUPn/5/

现在，要在同一行显示消息和按钮，您需要使用float。

#msg { float: left; }

Answer 2

使用＆＃39; setInterval（code，millisec）＆＃39;功能。所以你的代码应该是这样的：

var msgPtr =0;
var set_interval_id;

function pause() {
    clearInterval(set_interval_id)
}

function play() {
    set_interval_id = setInterval(function() {
        nextMsg(msgPtr);
        msgPtr++;
    }, 2000 /* how often to execute the code (2 sec) */);
}

window.onload = function () {
  play();
}

...

<button onclick="nextMsg(-1)">&lt;</button>
<button onclick="pause()">||</button>
<button onclick="nextMsg(1)">&gt;</button>

....

JS Text Loop with Previous，Pause＆amp;下一个按钮

2 个答案: