摘要：<!DOCTYPE html> <html> <head> <meta charset="UTF-8"> <title>js微博输入</title> <style> body{font-size: 12px;} .box{ width: 600p
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>js微博输入</title>
<style>
body{font-size: 12px;}
.box{ width: 600px; height: 160px; 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: 31px;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: #ffc09f;color: #fff; border-radius: 5px; }
</style>
<script>
var text,number,m
window.onload = function () {
text = document.getElementById('text');
number = document.getElementById('nuber')
bt = document.getElementById('bt')
text.onkeyup = function a(){
m=140-text.value.length
if(m<0){
number.style.color = "red"
}else {
number.style.color = "#888"
}
number.innerHTML = m
}
bt.onclick = function(){
if (m==140) {
alert("你还没有输入文字")
text.focus()
}else if (m<0) {
alert("字数超出限制，无法发布")
text.focus()
}else {
alert("发布成功")
}
}
a();
}
</script>
</head>
<body>
<div>
<img src="images/12.png">
<div>还可以输入<span id="nuber"></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" id="bt" value="发布">
</div>
</body>
</html>
批改老师：PHP中文网批改时间：2018-11-04 17:33:00
老师总结：逻辑正常，不过a()这种函数名称尽量不要再用了，无意义的函数名称不利于后期维护，js中少用全局变量，代码写多了的话，很容易引起莫名其妙的变量覆盖问题
