abstract：<!DOCTYPE html><html> <head> <meta charset="UTF-8"> <title>微博輸入</title> <style type="text/css"> body { font-size: 12px; } #
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>微博輸入</title>
<style type="text/css">
body {
font-size: 12px;
}
#box {
width: 600px;
height: 170px;
border: 8px 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 #888;
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: 150px;
margin-right: 15px;
color: #888;
}
#bt {
float: left;
width: 80px;
height: 30px;
border: none;
background: #ffc09d;
color: #fff;
border-radius: 5px;
}
</style>
<script type="text/javascript">
var text, number, 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 //限定微博字?jǐn)?shù)長度140個
if(m < 0) {
number.style.color = "#FF5000"
} else {
number.style.color = "#888"
}
number.innerHTML = m
}
bt.onclick = function() {
if(m >= 140) {
alert("你還沒有輸入")
text.focus()
} else if(m < 0) {
alert("字?jǐn)?shù)太多，不可以發(fā)布")
text.focus()
} else {
alert("發(fā)布成功")
}
}
aa()
}
</script>
</head>
<body>
<div id="box">
<img src="images/12.png">
<div id="box1">還可以輸入<span id="number"></span>字</div>
<textarea id="text"></textarea>
<span id="sp1">表情</span>
<span id="sp2">圖片</span>
<span id="sp3">視頻</span>
<span id="sp4">話題</span>
<span id="sp5">長微博</span>
<span id="sp6">公開</span>
<input type="button" value="發(fā)布" id="bt" >
</div>
</body>
</html>
這段代碼我發(fā)現(xiàn)了一個小bug如果頁面刷新后什么也不輸入點擊發(fā)布是會提示發(fā)布成功，請老師解答
Correcting teacher：天蓬老師Correction time：2019-01-03 15:20:56
Teacher's summary：background: url(images/an4.png) no-repeat left center;設(shè)置背景圖片,推薦寫完整: background-image