abstract：<!DOCTYPE html><html><head> <meta charset="utf-8"> <title>微博输入</title> <style type="text/css"> .box{width: 600px;height: 160px;border: 10
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>微博输入</title>
<style type="text/css">
.box{width: 600px;height: 160px;border: 10px solid pink;margin:0 auto;padding: 10px;}
img{float: left;}
.box1{float: left;margin-left: 255px;width: 150px;height: 24px;text-align: right;font-size: 14px;color: #888;}
.box1 span{font-size: 16px;font-weight: bold;}
#text{width: 600px;height: 100px;border: 1px solid #888;margin-top: 5px;}
.box #sp1,#sp2,#sp3,#sp4,#sp5,#sp6{float: left;width: 30px;height: 32px;line-height: 32px;padding-left: 26px;font-size: 14px;}
#sp1{background: url(images/an5.png) no-repeat left center;}
#sp2{background: url(images/an4.png) no-repeat left center;}
#sp3{background: url(images/an3.png) no-repeat left center;}
#sp4{background: url(images/an2.png) no-repeat left center;}
#sp5{background: url(images/an1.png) no-repeat left center;width: 40px;}
#sp6{margin-left: 150px;margin-right: 15px;color: #888;}
#bt{float: left;width: 80px;height: 30px;border: none;background: #ffc097;color: #fff;}
</style>
<script type="text/javascript">
var number,text,m
window.onload=function(){
text = document.getElementById("text");
number = document.getElementById("number");
bt = document.getElementById("bt");
text.onkeyup = function aa(){
m = 140-text.value.length //微博的限制字数140
if(m<0){
number.style.color = "red";
}else{
number.style.color="#888";
}
number.innerHTML = m;
}
bt.onclick = function(){
if(m==140){
alert('你还没有输入')
text.focus();
}else if(m<0){
alert('字符数超出')
}else{
alert('发布成功')
}
}
}
</script>
</head>
<body>
<div class="box">
<img src="images/12.png">
<div class="box1">还可以输入<span id="number"></span></div>
<textarea id="text"></textarea>
<span id="sp1">表情</span>
<span id="sp2">图片</span>
<span id="sp3">视频</span>
<span id="sp4">话题</span>
<span id="sp5">微博</span>
<span id="sp6">公开</span>
<input type="button" name="" id="bt" value="发布">
</div>
</body>
</html>
获取到id对象后调用对象方法或者属性
Correcting teacher：灭绝师太Correction time：2019-03-18 09:35:02
Teacher's summary：课堂案例比较简单基础,可以找其他案例练手哦!