js运动8 简单发状态

2017-03-20  本文已影响0人  maomizone
  • 发状态时判断内容是否为空

HTML (css样式忽略)

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>发状态</title>
    <script src="js/move2.js"></script>
</head>
<body>
<div>
    <textarea id="txt" cols="40"></textarea>
    <br/>
    <button id="btn">发布</button>
</div>

<div>
    <h2>状态栏</h2>
    <ul id="ul"></ul>
</div>

</ul>
</body>
</html>

JS

   <script>
        window.onload = function(){
            var txt = document.getElementById("txt");
            var btn = document.getElementById("btn");
            var ul = document.getElementById("ul");
            var lis = ul.getElementsByTagName("li");

            btn.onclick = function(){
                if(txt.value.trim() == ""){
                    alert("请输入");
                    return;
                }
                var li = document.createElement("li");
                li.innerHTML = txt.value;

                if(lis.length == 0){
                    ul.appendChild(li)
                }else{
                    ul.insertBefore(li, lis[0]);
                }
                var iHeight = li.offsetHeight;
                li.style.height = 0;
                move(li,{height: iHeight}, function(){
                    move(li, {opacity: 100});
                })

            }

        }
    </script>

效果

jsSport9.gif
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