js prohibits browser back event-JS Tutorial-php.cn

js prohibits browser back event

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Release： 2018-04-18 14:56:02

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This time I will bring you js to disable browser back events. What are the precautions for js to disable browser back events? The following is a practical case, let’s take a look.

In the project, I encountered the problem of pressing the Backspace key to make the browser go back. I searched for several solutions on the Internet, but none of them were ideal. So we gathered everyone’s wisdom and learned from the strengths of many families, and summarized it as follows:

1. Define the method to prevent Backspace in public js

function banBackSpace(e){
 var ev = e || window.event;
 //各种浏览器下获取事件对象
 var obj = ev.relatedTarget || ev.srcElement || ev.target ||ev.currentTarget;
 //按下Backspace键
 if(ev.keyCode == 8){
 var tagName = obj.nodeName //标签名称
 //如果标签不是input或者textarea则阻止Backspace
 if(tagName!='INPUT' && tagName!='TEXTAREA'){
  return stopIt(ev);
 }
 var tagType = obj.type.toUpperCase();//标签类型
 //input标签除了下面几种类型，全部阻止Backspace
 if(tagName=='INPUT' && (tagType!='TEXT' && tagType!='TEXTAREA' && tagType!='PASSWORD')){
  return stopIt(ev);
 }
 //input或者textarea输入框如果不可编辑则阻止Backspace
 if((tagName=='INPUT' || tagName=='TEXTAREA') && (obj.readOnly==true || obj.disabled ==true)){
  return stopIt(ev);
 }
 }
}
function stopIt(ev){
 if(ev.preventDefault ){
 //preventDefault()方法阻止元素发生默认的行为
 ev.preventDefault();
 }
 if(ev.returnValue){
 //IE浏览器下用window.event.returnValue = false;实现阻止元素发生默认的行为
 ev.returnValue = false;
 }
 return false;
}

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The method comments are very clear, so I won’t explain too much here.

2. Call this method after the page is loaded

$(function(){
 //实现对字符码的截获，keypress中屏蔽了这些功能按键
 document.onkeypress = banBackSpace;
 //对功能按键的获取
 document.onkeydown = banBackSpace;
 })

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Note: Key event triggering sequence: keydown -> keypress ->textInput -> keyup

There is a problem: after the select

drop-down list is expanded, the keyboard event cannot be obtained. If you press the Backspace key at this time, the browser will still go back to the history; solution: change the select drop-down box to easyUI's combobox;

I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the php Chinese website!