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微博輸入數(shù)字案例的練習(xí)

original 2019-02-21 15:22:57 211
abstrait:<!DOCTYPE html><html><head> <meta charset="utf-8"> <title>Document</title> <link rel="stylesheet" type="text/css" href=""

<!DOCTYPE html>

<html>

<head>

<meta charset="utf-8">

<title>Document</title>

<link rel="stylesheet" type="text/css" href="">

<link rel="shortcut icon" type="image/x-icon" href="">


<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: 225px;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: 150px;margin-right: 15px;color: #888;}

#bt{float: left;width: 80px;height: 30px;border: none;background:#ffc09f;color: #fff;border: 5px;}


</style>


<script type="text/javascript">

var text,number,m,bt;

m = 140;

window.onload = function(){

text = document.getElementById("text");

number = document.getElementById("number");

bt = document.getElementById("bt");

text.onkeyup =function aa(){

m = m- text.value.length;

if(m<0){

number.style.color = "red";

}else{

number.style.color = "#888";

}

number.innerHTML = m;

}



bt.onclick =function bb(){

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");

}

}

}



</script>

<body>

<div class="box">

<img src="images/12.png">

<div class="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" name="發(fā)布" value="發(fā)布"  id="bt">


</div>


</body>

</html>


總結(jié):在視頻的案例代碼中,如果沒有點(diǎn)擊textarea,直接點(diǎn)擊發(fā)布,可以發(fā)布成功,我檢查了一下是因?yàn)閙沒有給初始值,那時(shí)候m為0。我修改了一下,給了初始值。


Professeur correcteur:滅絕師太Temps de correction:2019-02-21 15:36:05
Résumé du professeur:bb()這個(gè)函數(shù)名可以去掉,要理解代碼含義,不可照葫蘆畫瓢哦!

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