The example in this article describes the method of dynamically setting style using javascript. Share it with everyone for your reference. The specific analysis is as follows:
Dynamic modification of style
1. Error-prone: Modifying the style of an element is not to set the class attribute, but the className attribute.
2. Error-prone: Use "style.attribute name" to modify the style attributes individually. Note that the attribute name in CSS is in JavaScript
The attribute names may be different during operation, mainly focusing on those attributes whose attribute names contain -, because
In JavaScript - attributes and class names cannot be used. Therefore, the background color in CSS is background-clolor, while in JavaScript it is style.background; the element style name is class, and in JavaScript it is the className attribute; font-size->style.fontSize; margin-top->style .marginTop
3. Modify the style of the control individually
1. Example 1
<html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>动态修改style</title> <style type="text/css"> .day { background-color:Green; } .night { background-color:Black; } </style> <script type="text/javascript"> function dayclick() { var divMain = document.getElementById("divMain"); //注意这里使用的是className而不是class divMain.className = "day"; } function nightclick() { var divMain = document.getElementById("divMain"); divMain.className = "night"; } </script> </head> <body> <div id="divMain" class="day"> <font color="red">中华人名共和国</font> </div> <input type="button" value="白天" onclick="dayclick()" /> <input type="button" value="黑夜" onclick="nightclick()" /> </body> </html>
2. Example: dynamically modify style (simulate turning on and off lights)
<html xmlns="http://www.w3.org/1999/xhtml"> <head> <title></title> <style type="text/css"> .day { background-color:White; } .night { background-color:Black; } </style> <script type="text/javascript"> function switchLight() { var btnSwitch = document.getElementById("btnSwitch"); if (document.body.className == "day") { document.body.className = "night"; btnSwitch.value = "开灯"; } else { document.body.className = "day"; btnSwitch.value = "关灯"; } } </script> </head> <body class="night"> <input type="button" value="开灯" id="btnSwitch" onclick="switchLight()"/> </body> </html>
3. Example:
<html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>动态设置style练习(修改文本框背景色)</title> <script type="text/javascript"> function IniEvents() { var inputs = document.getElementsByTagName("input"); for (var i = 0; i < inputs.length; i++) { if (inputs[i].type == "text") { //设置txtOnBlur函数为input元素的onblur事件的响应函数 inputs[i].onblur = txtOnBlur; } } } function txtOnBlur() { /* txtOnBlur是onblur的响应函数,而不是被响应函数调用 的函数,所有可以用this来取的发生事件控件的对象 */ if (this.value.length <= 0) { this.style.background = "red"; } else { this.style.background = "white"; } } </script> </head> <body onload="IniEvents()"> <input type="text" /><br /> <input type="text" /><br /> <input type="text" /><br /> <input type="text" /><br /> <input type="text" /><br /> <input type="text" /><br /> </body> </html>
I hope this article will be helpful to everyone’s JavaScript programming design.