tryfinally妙用,防止內存泄漏_javascript技巧

來源：懂視網責編：小采時間：2020-11-27 20:38:56

tryfinally妙用,防止內存泄漏_javascript技巧

tryfinally妙用,防止內存泄漏_javascript技巧: function createButton(){ var obj = document.createElement(button); obj.innerHTML=點我!; obj.onclick=function(){ //處理click事件 } obj.onmouseover=function(){ //處理mouseover事件 } r

推薦度：

點擊下載本文 文檔為doc格式

導讀tryfinally妙用,防止內存泄漏_javascript技巧: function createButton(){ var obj = document.createElement(button); obj.innerHTML=點我!; obj.onclick=function(){ //處理click事件 } obj.onmouseover=function(){ //處理mouseover事件 } r

[Ctrl+A 全選注:如需引入外部Js需刷新才能執行]
這種寫法在IE中100%內存泄漏

使用try finally很容易解決些問題
代碼如下:
function createButton(){
var obj = document.createElement("button");
obj.innerHTML="點我!";
obj.onclick=function(){
//處理click事件
}
obj.onmouseover=function(){
//處理mouseover事件
}
try{
return obj;
}finally{
obj = null;//這句話在return 之后才執行,有效地解決了需在return后將obj置null的問題
}
}

一個函數或方法中，其實有很多地方都需要這種選返回值，最后執行某些事的

=====================================================================
附一:JavaScript Error (try/catch/finally)
Introduction
Like other programming languages, JavaScript provides the possibility to make use of
the try/catch/finally block. Usually when an error is encountered then the script stops and doesn't
continue with the rest of the page. The try/catch/finally block can be used to continue the
processing with the rest of the page. You just have to put the code in your try block and when
an error in encountered there, then it will call the catch block. The finally block is called always
regardless of an error occurred or not. The following example makes the usage clear.

Example:
<html> <head> </head> <body> <script type="text/javascript"> try { document.write(unknownVariable) } catch(e) { document.write(e.message + " ") } finally { document.write("This is the finally message.") } </ script> </body> </html>
[Ctrl+A 全選注:如需引入外部Js需刷新才能執行]

聲明：本網頁內容旨在傳播知識，若有侵權等問題請及時與本網聯系，我們將在第一時間刪除處理。TEL:177 7030 7066 E-MAIL:11247931@qq.com

tryfinally妙用,防止內存泄漏_javascript技巧

推薦度：

點擊下載本文 文檔為doc格式

標簽：內存 js javascript

熱門焦點

tryfinally妙用,防止內存泄漏_javascript技巧

tryfinally妙用,防止內存泄漏_javascript技巧

tryfinally妙用,防止內存泄漏_javascript技巧

最新推薦

猜你喜歡

熱門推薦