jquery off() method-JS Tutorial-php.cn

off()function is used toremove one or more events bound to an elementEvent handlingfunction.

off()The function is mainly used to unblock the event processing function bound by the on() function.

This function belongs to thejQueryobject (instance).

Syntax

jQuery1.7 Add this function. It mainly has the following two forms of usage:

Usage one:

jQueryObject.off( [ events [, selector ] [, handler ] ] )

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Usage two:

jQueryObject.off( eventsMap [, selector ] )

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Parameters

Parameter	Description
events	Optional/ String type one or more event types separated by spaces and optionalnamespace, such as "click", "focus click", "keydown.myPlugin".
eventsMap	Object type is anObject object, each of its properties corresponds to the event type and optional namespace (Parameter`events`), the attribute value corresponds to the bound event processing function (Parameter`handler`).
selector	Optional/String type A jQuery selector used to specify which descendant elements can trigger bound events. If this parameter is`null`or is omitted, it means that the current element itself is bound to the event (the actual triggerer may also be a descendant element, as long as the event stream can reach the current element).
handler	Optional/Event handling function specified by Function type.

off()The function will remove the # bound to the descendant elementselectoron the current matching element. ##eventsEvent handling functionhandler.

If the parameter

selectoris omitted, the event handler bound to any element is removed.

Parameters

selectorMust be consistent with the selector passed in when adding binding through the on() function.

If the parameter

handleris omitted, all event handlers bound to the specified event type of the specified element will be removed.

If all parameters are omitted, it means to remove any event handler function of any event type bound to any element on the current element.

Return value

off()The return value of the functionis ofjQuery type and returns the current jQuery object itself.

In fact, the parameters of the

off()functionare all filtering conditions, and only event processing functions that match all parameter conditions will be removed. The more parameters there are, the more qualifications there are and the smaller the range that is removed.

Example & Description

Please refer to the following initial HTML code:

 id="btn1" type="button" value="点击1" />
 id="btn2" type="button" value="点击2" />
 id="a1" href="#">CodePlayer

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First, we bind events to the above button and elements, and then use

off()The function unbinds the event. The corresponding code is as follows:

function btnClick1(){
 alert( this.value + "-1" );
}

function btnClick2(){
 alert( this.value + "-2" );
}

var $body = $("body");

// 为所有button元素的click事件绑定事件处理函数btnClick1
$body.on("click", ":button", btnClick1 );

// 为所有button元素的click事件绑定事件处理函数btnClick2
$body.on("click", ":button", btnClick2 );

//为所有a元素绑定click、mouseover、mouseleave事件
$body.on("click mouseover mouseleave", "a", function(event){
 if( event.type == "click" ){
 alert("点击事件");
 }else if( event.type == "mouseover" ){
 $(this).css("color", "red");
 }else{
 $(this).css("color", "blue"); 
 }
});


// 移除body元素为所有button元素的click事件绑定的事件处理函数btnClick2
// 点击按钮，btnClick1照样执行
$body.off("click", ":button", btnClick2);


// 移除body元素为所有button元素的click事件绑定的所有事件处理函数(btnClick1和btnClick2)
// 点击按钮，不会执行任何事件处理函数
// $body.off("click", ":button");


// 注意： $body.off("click", "#btn1"); 无法移除btn1的点击事件，off()函数指定的选择器必须与on()函数传入的选择器一致。


// 移除body元素为所有元素(包括button和元素)的click事件绑定的所有处理函数
// 点击按钮或链接，都不会触发执行任何事件处理函数
// $("body").off("click");


// 移除body元素为所有元素的任何事件绑定的所有处理函数
// 点击按钮，或点击链接或者鼠标移入/移出链接，都不会触发执行任何事件处理函数
// $("body").off( );

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Run the code (please copy other codes to the demo page to run)

In addition

off ()The function can also remove only the event binding of the specified namespace.

var $btn1 = $("#btn1");

$btn1.on("click.foo.bar", function(event){
 alert("click-1");
});
$btn1.on("click.test", function(event){
 alert("click-2");
});
$btn1.on("click.test.foo", function(event){
 alert("click-3");
});

$btn1.off("click.test"); // 移除click-2、click-3

// $btn1.off("click.foo"); // 移除click-1、click-3

// $btn1.off("click.foo.bar"); // 移除click-1

// $btn1.off("click"); // 移除所有click事件处理函数(click-1、click-2、click-3)

// $btn1.off(".foo"); // 移除所有包含命名空间foo的事件处理函数，不仅仅是click事件