function doSomethingWith(param) { document.body.addEventListener( ‘scroll’, function() { document.write(param); }, false ); // An event that I want to remove later } setTimeout( function() { document.body.removeEventListener(‘scroll’, HANDLER ,false); // What HANDLER should I specify to remove the anonymous handler above? }, 3000 ); doSomethingWith(‘Test. ‘);
你不能 您必须使用命名函数或以某种方式存储引用。
var handler; function doSomethingWith(param) { handler = function(){ document.write(param); }; document.body.addEventListener('scroll', handler,false); } setTimeout(function() { document.body.removeEventListener('scroll', handler ,false); }, 3000);
最好是以结构化的方式执行此操作,以便您可以标识不同的处理程序并将其删除。在上面的示例中,您显然只能删除最后一个处理程序。
更新:
您可以创建自己的处理程序处理程序(:)):
var Handler = (function(){ var i = 1, listeners = {}; return { addListener: function(element, event, handler, capture) { element.addEventListener(event, handler, capture); listeners[i] = {element: element, event: event, handler: handler, capture: capture}; return i++; }, removeListener: function(id) { if(id in listeners) { var h = listeners[id]; h.element.removeEventListener(h.event, h.handler, h.capture); delete listeners[id]; } } }; }());
然后,您可以将其用于:
function doSomethingWith(param) { return Handler.addListener(document.body, 'scroll', function() { document.write(param); }, false); } var handler = doSomethingWith('Test. '); setTimeout(function() { Handler.removeListener(handler); }, 3000);