jquery cancels scroll event listening

When we develop web applications, we often need to monitor the user's scrolling behavior on the page. At this time, we can use the scroll event provided by jQuery to monitor the user's scroll operation. However, in some cases, we need to cancel the monitoring of scroll events, which requires using some APIs provided by jQuery to achieve this.

Next, we will introduce in detail how to use jQuery to cancel the monitoring of scroll events.

1. Methods provided by jQuery to cancel scrolling event monitoring

jQuery provides three methods to cancel scrolling event monitoring, they are: off(), unbind( ) and unbindAll().

(1) off() method

The off() method is used to cancel all event listeners bound to DOM elements. The syntax is as follows:

$(selector).off(event,[selector],[function])

Among them, selector represents the selector of the DOM element to be canceled, event represents the event name to be canceled, and function represents the event processing function to be canceled.

If only event is specified, all listeners for the event bound to the selector will be cancelled. If both event and function are specified, only the specified listener will be cancelled.

(2) unbind() method

The unbind() method is also used to cancel the listener for events bound to DOM elements. Its syntax is similar to the off() method, as shown below:

$(selector).unbind(event,[function])

Among them, selector represents the selector of the DOM element to be canceled, event represents the event name to be canceled, and function represents the event to be canceled. processing function.

The difference between this method and the off() method is that the unbind() method will only cancel the listener of the specified handler function of the specified event bound to the selector element.

(3) unbindAll() method

The unbindAll() method is a method specially provided by jQuery to cancel all bound event listeners. The syntax is as follows:

$(selector).unbind()

This method will cancel all bound event listeners on the selector element.

2. How to use jQuery to cancel the monitoring of scroll events

Next, we take the off() method as an example to introduce how to use jQuery to cancel the monitoring of scroll events. .

For example, the following code is a code that monitors page scrolling:

$(window).scroll(function(){
    console.log("scroll!");
});

This code will print out a "scroll!" prompt message when the window scrolls.

If you want to cancel this listener, you only need to add the off() method to the code, as shown below:

$(window).off("scroll");

This line of code will cancel all bindings on the window element. Listener for scroll events.

If you only want to cancel one of the listeners, you need to specify event and function at the same time, as shown below:

$(window).off("scroll",function(){
    console.log("scroll!");
});

This line of code will only unbind the window element and the processing function is console. The listener for the scroll event of .log("scroll!").

3. Summary

The above are the methods and steps for using jQuery to cancel the monitoring of scroll events. It should be noted that:

• You can use off (), unbind() and unbindAll() methods to cancel the event listener; the
• off() method can cancel the listener of all events, or only the specified event, or only the specified event. Specify the listener;
• The unbind() method can only cancel the specified listener for the specified event;
• The unbindAll() method is specially used to cancel the listener for all events;
• You can choose which method to use to cancel the event listener based on actual needs.

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