解决IE6内存泄露的另类方法

Hedger Wang 在国内 blog 上得到的方法：使用 try … finally 结构来使对象最终为 null ，以阻止内存泄露。其中举了个例子： function createButton() { var obj = document.createElement("button"); obj.innerHTML = "click me"; obj.onclick = function() { //handle onclick } obj.onmouseover = function() { //handle onmouseover } return obj;//return a object which has memory leak problem in IE6 } var dButton = document.getElementsById("d1").appendChild(createButton()); //skipped....对于 IE6 中，引起内存泄露的原因，可看《Understanding and Solving Internet Explorer Leak Patterns》一文。上面的例子，应该属于上文中的 “Closures”原因。 再看下用 try … finally 的解决方法： /** * Use the try ... finally statement to resolve the memory leak issue */ function createButton() { var obj = document.createElement("button"); obj.innerHTML = "click me"; obj.onclick = function() { //handle onclick } obj.onmouseover = function() { //handle onmouseover } //this helps to fix the memory leak issue try { return obj; } finally { obj = null; } } var dButton = document.getElementsById("d1").appendChild(createButton()); //skipped....可能大家有疑问： finally 是如何解析的呢？答案是：先执行 try 语句再执行 finally 语句。例如： function foo() { var x = 0; try { return print("call return " + (++x)); } finally { print("call finally " + (++x)); } } print('before'); print(foo()); print('after'); 返回的结果为： print » before print » call return 1 print » call finally 2 print » true print » after