摘要:发现课程代码中一个BUG。当文本框没有获取到焦点的时候,直接点提交。视频里的代码貌似会提示发布成功,因为这个时候M不等于140也不小于0,这时的值是:undefined<!DOCTYPE html><html><head><meta charset="UTF-8"><title>Document</title&g
发现课程代码中一个BUG。当文本框没有获取到焦点的时候,直接点提交。视频里的代码貌似会提示发布成功,因为这个时候M不等于140也不小于0,这时的值是:undefined
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
#box{width: 800px; height: 300px; border: 8px solid pink; margin: 0px auto;padding: 15px;}
#jishu{font-size: 14px; font-weight: bold; color: #ccc; font-family: 宋体;margin-right: 20px;margin-left: 475px; line-height: 20px;}
#neirong{width: 780px; height: 230px;border:2px solid #ccc; margin-top: 5px;}
.sp1,.sp2,.sp3,.sp4,.sp5,.sp6{line-height: 25px;padding-left: 26px; width: 40px; height: 30px; 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;}
.sp6{margin-left: 320px;color: #888;}
#fabu{margin-left: 10px;width: 70px;height: 30px;border:0px; background: #FFC79E; border-radius: 5px;}
</style>
<script>
var m,num,text,tijiao;
window.onload=function() {
tijiao=document.getElementById("fabu")
text=document.getElementById("neirong");
num=document.getElementById("num");
m=140-text.value.length
text.onkeyup=function a(){
m=140-text.value.length
if (m<0) {
num.style.color="red"
}else{
num.style.color="#888"
}
num.innerHTML=m
}
tijiao.onclick=function (){
if (m==140) {
alert("您还没有输入内容!")
text.focus()
}else if(m<0){
alert("字数太多,无法发布!")
text.focus()
}else{
alert("发布成功!")
}
}
}
</script>
</head>
<body>
<div id="box">
<img src="images/12.png" alt=""><span id="jishu">还可以输入<b id="num"></b>字</span>
<textarea id="neirong"></textarea>
<span>表情</span>
<span>图片</span>
<span>视频</span>
<span>话题</span>
<span>长微博</span>
<span>公开</span>
<input type="button" value="发布" ID="fabu">
</div>
</body>
</html>
批改老师:灭绝师太批改时间:2018-11-20 09:04:01
老师总结:其实也不是bug,这里少做了一个判断啦,自己加上!