JS Event Monitoring

AddEventListener () method

element. AddEventListener (event, function, Usecapture);

The first parameter is the type of event (such as "click" or "MouseDown").

The second parameter is a function that is called after the event is triggered.

The third parameter is a Boolean value that describes whether the event is bubbling or capturing. This parameter is optional.

Note: Do not use the "on" prefix. For example, use "click" instead of "onclick".

"Hello world!" pops up when the user clicks on an element:

element. AddEventListener ("click", Function () {alert ("Hello world!");}); You can use the function name to refer to an external function:

"Hello world!" pops up when the user clicks on an element:

element. AddEventListener ("click", MyFunction);

function MyFunction () {
Alert ("Hello world!");
When passing a parameter value, use an anonymous function to invoke the function with the parameter: element. AddEventListener ("click", Function () {myFunction (P1, p2);});

The AddEventListener () method can specify the "usecapture" parameter to set the delivery type:

AddEventListener ( Event, function, usecapture);

The default is False, which is the bubbling pass, when the value is true, and the event uses capture delivery.

document.getElementById ("Mydiv"). AddEventListener ("Click", MyFunction, True); RemoveEventListener () method

The RemoveEventListener () method removes the event handle added by the AddEventListener () method:

Instance element. RemoveEventListener ("MouseMove", myFunction);

Cross-Browser Workaround:

var x = document.getElementById ("mybtn");
if (X.addeventlistener) {//All major browsers except IE 8 and earlier
X.addeventlistener ("click", MyFunction);
} else if (x.attachevent) {///IE 8 and earlier versions
X.attachevent ("onclick", myFunction);
}

JS Event Monitoring