abstract：<!DOCTYPE html> <html><head> <meta charset="utf-8"> <title>微博输入</title>
<!DOCTYPE html>
<html><head>
<meta charset="utf-8">
<title>微博输入</title>
<script src="https://code.jquery.com/jquery-3.1.1.min.js"></script>
<style type="text/css">
body {
font-size: 12px;
}
.box {
width: 600px;
height: 160px;
border: 10px solid pink;
margin: 0px 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 #ccc;
margin-top: 5px;
}
.box #sp1, #sp2, #sp3, #sp4, #sp5, #sp6 {
float: left;
width: 30px;
height: 32px;
line-height: 32px;
padding-left: 26px;
}
#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: 158px;
margin-right: 15px;
color: #888;
}
#bt {
float: left;
width: 80px;
height: 30px;
border: none;
background: #ffc09f;
color: #fff;
border-radius: 5px;
}
</style>
<script type="text/javascript">
/* Jquery版本 */
$('document').ready(function() {
$('#text').keyup(function(){
var len=140- $(this).val().length;
if(len<0){
$('#number').css('color','red');
}else{
$('#number').css('color','red');
};
$('#number').html(len);
});
$('#bt').click(function(){
_len=140-$('#text').val().length;
if(_len ==140){
alert('您还没有输入内容');
$('#text').focus();
}else if(_len<0){
alert('字数超出限制，请检查');
$('#text').focus();
}else{
alert('发布成功')
}
});
});
/*
Javascript版本
//var str,num,obj
window.onload=function (){
str=document.getElementById("text");
num=document.getElementById("number");
bt=document.getElementById("bt");
str.onkeyup=function key(){
o=140-str.value.length;
if(o<0){
num.style.color="red";
}else{
num.style.color="blue";
}
num.innerHTML=o;
}
bt.onclick=function(){
if(o ==140){
alert('请输入内容');
str.focus();
}else if(o<0){
alert('超出规定字符数');
str.focus();
}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">140</span>字</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">长微博</span> <span id="sp6">公开</span>
<input type="button" value="发布" id="bt">
</div>
</body>
</html>
Correcting teacher：天蓬老师Correction time：2019-06-16 09:31:24
Teacher's summary：jQuery中, 推荐使用 on() 来给元素设置事件方法, 以后尽可能用on