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How to express centering in javascript
- 藏色散人Original
- 2021-06-30 09:46:074530browse
The implementation method of JavaScript centering: first get the browser window; then get the div element of main; then calculate the position through the width and height of the window and the width and height of div; finally get the div element of mcontent.
The operating environment of this article: windows7 system, javascript version 1.8.5, Dell G3 computer.
Specific question:
How to indicate that JavaScript is centered?
js centers the div content
var button=document.createElement("input");
button.setAttribute("type","button");
button.setAttribute("id","button1");To center the button inside the div, use js instead of html
Implementation method:
text-align: center;
line-height:100px; /*行间距和div宽度相同*/
}
</style>
<body>
<div id="main">
<div id="content">
Sun
</div>
</div>
<script type="text/javascript">
window.onload = function() {
// 获取浏览器窗口
var windowScreen = document.documentElement;
// 获取main的div元素
var main_div = document.getElementById("main");
// 通过窗口宽高和div宽高计算位置
var main_left = (windowScreen.clientWidth - main_div.clientWidth)/2 + "px";
var main_top = (windowScreen.clientHeight - main_div.clientHeight)/2 + "px";
// 位置赋值
main_div.style.left = main_left;
main_div.style.top = main_top;
// 获取mcontent的div元素
var content_div = document.getElementById("content");
var content_left = (main_div.clientWidth - content_div.clientWidth)/2 + "px";
var content_top = (main_div.clientHeight - content_div.clientHeight)/2 + "px";
content_div.style.left = content_left;
content_div.style.top = content_top;
}
</script>
</body>Extended information
Div top and bottom centering code
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <html> <title>Div上下居中－www.51windows.Net</title> <head> <meta name="keywords" content="51windows.Net"> <meta http-equiv=content-type content="text/html; charset=gb2312"> </head> <body> <div style="position: absolute; top: 200; left: 0; width: 300; height: 200;border: 1 solid #C0C0C0;"> <div style="border: 1 solid red;position: absolute;top:expression((this.parentElement.offsetHeight-this.offsetHeight)/2);left:expression((this.parentElement.offsetWidth-this.offsetWidth)/2);">我站在中央了 center</div> </div> <div style="border: 1 solid #C0C0C0;"> <div style="border: 1 solid red;position: absolute;top:expression((this.parentElement.offsetHeight-this.offsetHeight)/2);left:expression((this.parentElement.offsetWidth-this.offsetWidth)/2);">我站在中央了 center</div> </div> </body> </html>
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