封装了一个支持匿名函数的Javascript事件监听器_javascript技巧
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2022-03-26 23:38:00
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关于js中的事件监听大家用的比较多了,无非是判断浏览器是否支持addEventListener和attachEvent,网上搜索关于事件监听的方法也挺多,但是总有些不是很完善。下面的方法中对于添加事件监听的方法是一样的,只不过在取消事件绑定上面做了点手术,现在可以支持匿名函数的使用,所以在绑定事件的时候不再需要给函数单独命名了。
/*绑定事件与取消绑定*/
var handleHash = {};
var bind = (function() {
if (window.addEventListener) {
return function(el, type, fn, capture) {
el.addEventListener(type, function(){
fn();
handleHash[type] = handleHash[type] || [];
handleHash[type].push(arguments.callee);
}, capture);
};
} else if (window.attachEvent) {
return function(el, type, fn, capture) {
el.attachEvent("on" + type, function(){
fn();
handleHash[type] = handleHash[type] || [];
handleHash[type].push(arguments.callee);
});
};
}
})();
var unbind = (function(){
if (window.addEventListener) {
return function(el, type ) {
if(handleHash[type]){
var i = 0, len = handleHash[type].length;
for (i; i el.removeEventListener(type, handleHash[type][i]);
}
};
};
} else if (window.attachEvent) {
return function(el, type) {
if(handleHash[type]){
var i = 0, len = handleHash[type].length;
for (i; i el.detachEvent("on" + type, handleHash[type][i]);
}
};
};
}
})();
bind(obj,'click',function(){
alert ('click');
});
unbind(obj,'click');
主要代码:
复制代码 代码如下:
/*绑定事件与取消绑定*/
var handleHash = {};
var bind = (function() {
if (window.addEventListener) {
return function(el, type, fn, capture) {
el.addEventListener(type, function(){
fn();
handleHash[type] = handleHash[type] || [];
handleHash[type].push(arguments.callee);
}, capture);
};
} else if (window.attachEvent) {
return function(el, type, fn, capture) {
el.attachEvent("on" + type, function(){
fn();
handleHash[type] = handleHash[type] || [];
handleHash[type].push(arguments.callee);
});
};
}
})();
var unbind = (function(){
if (window.addEventListener) {
return function(el, type ) {
if(handleHash[type]){
var i = 0, len = handleHash[type].length;
for (i; i
}
};
};
} else if (window.attachEvent) {
return function(el, type) {
if(handleHash[type]){
var i = 0, len = handleHash[type].length;
for (i; i
}
};
};
}
})();
原理解析:
handleHash做哈希表缓存事件的function,handleHash['事件名称']是一个数组,来添加多个事件监听的方法,unbind哪个事件的时候遍历handleHash['事件名称']的数组,然后移除。
使用:
复制代码 代码如下:
bind(obj,'click',function(){
alert ('click');
});
unbind(obj,'click');
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