jQuery.each( ("blur focus focusin focusout load resize scroll unload click dblclick " +"mousedown mouseup mousemove mouseover mouseout mouseenter mouseleave " +"change select submit keydown keypress keyup error contextmenu").split(" "), function( i, name ) {//合并15种事件统一增加到jQuery.fn上，内部调用this.on / this.triggerjQuery.fn[ name ] = function( data, fn ) {return arguments.length > 0 ?this.on( name, null, data, fn ) ://如果不带参数表示立刻触发指定事件this.trigger( name );};
});

bind: function( types, data, fn ) {return this.on( types, null, data, fn );
},
unbind: function( types, fn ) {return this.off( types, null, fn );
}

delegate: function( selector, types, data, fn ) {return this.on( types, selector, data, fn );
},
undelegate: function( selector, types, fn ) {// ( namespace ) or ( selector, types [, fn] )return arguments.length === 1 ? this.off( selector, "**" ) : this.off( types, selector || "**", fn );
}

one: function( types, selector, data, fn ) {return this.on( types, selector, data, fn, 1 );
}

//立刻触发jQuery对象内所有元素的指定type的事件
trigger: function( type, data ) {return this.each(function() {jQuery.event.trigger( type, data, this );});
},
//立刻触发jQuery对象内第一个元素的指定type的事件，且不会触发事件（比如表单提交）的默认行为
triggerHandler: function( type, data ) {var elem = this[0];if ( elem ) {return jQuery.event.trigger( type, data, elem, true );}
}

            //获取缓存数据 　　　　　　　elemData = jQuery._data( elem );...　　　　　　　　　　　　　  //设置缓存数据if ( !(events = elemData.events) ) {events = elemData.events = {};}if ( !(eventHandle = elemData.handle) ) {eventHandle = elemData.handle = function( e ) {...};//将elem作为handle函数的一个特征防止ie非本地事件引起的内存泄露eventHandle.elem = elem;}

        // handleObj：设置绑定事件信息。贯穿整个事件处理handleObj = jQuery.extend({type: type,origType: origType,data: data,handler: handler,guid: handler.guid,selector: selector,// For use in libraries implementing .is(). We use this for POS matching in `select`//"needsContext": new RegExp( "^" + whitespace + "*[>+~]|:(even|odd|eq|gt|lt|nth|first|last)(?:\\(" +//whitespace + "*((?:-\\d)?\\d*)" + whitespace + "*\\)|)(?=[^-]|$)", "i" )//用来判断亲密关系needsContext: selector && jQuery.expr.match.needsContext.test( selector ),namespace: namespaces.join(".")}, handleObjIn );

        //将事件对象handleObj添加到元素的处理列表,委托事件放在前面，委托代理计数递增if ( selector ) {handlers.splice( handlers.delegateCount++, 0, handleObj );} else {handlers.push( handleObj );}

//传入的参数是事件且绑定了处理函数
if ( types && types.preventDefault && types.handleObj ) {// ( event )  dispatched jQuery.EventhandleObj = types.handleObj;//types.delegateTarget是事件托管对象
        jQuery( types.delegateTarget ).off(//组合jQuery识别的typehandleObj.namespace ? handleObj.origType + "." + handleObj.namespace : handleObj.origType,handleObj.selector,handleObj.handler);return this;
}

off: function( types, selector, fn ) {var handleObj, type;//传入的参数是事件且绑定了处理函数if ( types && types.preventDefault && types.handleObj ) {// ( event )  dispatched jQuery.EventhandleObj = types.handleObj;//types.delegateTarget是事件托管对象
        jQuery( types.delegateTarget ).off(//组合jQuery识别的typehandleObj.namespace ? handleObj.origType + "." + handleObj.namespace : handleObj.origType,handleObj.selector,handleObj.handler);return this;}if ( typeof types === "object" ) {// ( types-object [, selector] )for ( type in types ) {this.off( type, selector, types[ type ] );}return this;}if ( selector === false || typeof selector === "function" ) {// ( types [, fn] )fn = selector;selector = undefined;}if ( fn === false ) {fn = returnFalse;}return this.each(function() {jQuery.event.remove( this, types, fn, selector );});
}

View Code

//分解types为type.namespace为单位元素的数组
types = ( types || "" ).match( core_rnotwhite ) || [""];
t = types.length;
while ( t-- ) {tmp = rtypenamespace.exec( types[t] ) || [];type = origType = tmp[1];namespaces = ( tmp[2] || "" ).split( "." ).sort(); //解绑当前元素的当前命名空间（types[ t ]）上所有的事件if ( !type ) {for ( type in events ) {jQuery.event.remove( elem, type + types[ t ], handler, selector, true );}continue;}...

type = ( selector ? special.delegateType : special.bindType ) || type;
handlers = events[ type ] || [];
tmp = tmp[2] && new RegExp( "(^|\\.)" + namespaces.join("\\.(?:.*\\.|)") + "(\\.|$)" );//删除匹配事件
origCount = j = handlers.length;
while ( j-- ) {handleObj = handlers[ j ]; //各种满足移除事件的条件才能移除if ( ( mappedTypes || origType === handleObj.origType ) &&( !handler || handler.guid === handleObj.guid ) &&( !tmp || tmp.test( handleObj.namespace ) ) &&( !selector || selector === handleObj.selector || selector === "**" && handleObj.selector ) ) {handlers.splice( j, 1 );
　　　　　　　　if ( handleObj.selector ) {handlers.delegateCount--;}
　　　　　　　　if ( special.remove ) {special.remove.call( elem, handleObj );}}
}

// 移除事件处理对象
// (移除特殊事件处理过程中避免潜在的无限递归，下一章会专门详解这种情况)
if ( origCount && !handlers.length ) {
//例如 var js_obj = document.createElement("div"); js_obj.onclick = function(){ …}
//上面的js_obj是一个DOM元素的引用，DOM元素它长期在网页当中，不会消失，而这个DOM元素的一属性onclick，又是内部的函数引用（闭包），而这个匿名函数又和js_obj之间有隐藏的关联（作用域链）所以形成了一个，循环引用.
if ( !special.teardown || special.teardown.call( elem, namespaces, elemData.handle ) === false ) {jQuery.removeEvent( elem, type, elemData.handle );
} delete events[ type ];
}

if ( jQuery.isEmptyObject( events ) ) {
　　delete elemData.handle;
　　//removeData还检事件对象是否为空，所以使用它替代deletejQuery._removeData( elem, "events" );
}

jQuery.removeEvent = document.removeEventListener ?
function( elem, type, handle ) {if ( elem.removeEventListener ) {elem.removeEventListener( type, handle, false );}
} :
function( elem, type, handle ) {var name = "on" + type;if ( elem.detachEvent ) {// #8545, #7054,避免自定义事件在IE6-8中的内存泄露// detachEvent需要传递第一个参数，不能是undefined的if ( typeof elem[ name ] === core_strundefined ) {elem[ name ] = null;}elem.detachEvent( name, handle );}
};