JavaScript event definition, binding events and command language in event driven

event

Definition of event
When an element in the document is operated or the state of the document changes, an event will be generated
Three elements of the event
Event source
Event
Event handler
Preparation knowledge
document.getElementById
document.getElementsByTagName
innerHTML
style
1. Only inline styles can be operated
backgroundColor 2. There is a horizontal background color Awesome css style should use camel case naming method
Binding events
1. In the html tag element onclick='function name()'
2. The way to use element objects
Event-driven
Mouse Event
onclick click event
ondblclick double-click event
onmouseover mouse move in
onmouseout mouse move out
oncontextmenu mouse right click
onmousedown mouse down
onmouseup mouse up
Onmousemove Mouse Mobile
Scrolltopt Put the content vertically
ScrollLeft to the content of the content of the content. )
Ctrlkey determines whether the keyboard Ctrl is pressed
Altkey to determine whether the keyboard ALT key is pressed
Shiftkey to determine whether the shift is pressed
Onepress Press the
to get the keyboard and press the keyboard ASCII value (case sensitive, system keys are not recognized)
onkeyup Keyboard raised
Form event
onfocus Focus on
onblur Lost focus
Case verification username
onsubmit form submission event
onchange When the value changes
onreset Form reset
onselect Triggered when the content of the text field is selected
Frame event
onload When the web page content is loaded
onerror When the document fails to load document.documentElement .scrollTop Get the scroll height IE
                                                                                                                                                                                                              . onscroll = function() {
// Google gets the scrolling distance
// var top = document.body.scrollTop;
// var left = document.body.scrollLeft;

// The scrolling distance obtained in Firefox IE
// var top = document.documentElement.scrollTop;

// Compatible with Firefox and Google IE
var top = document.body.scrollTop || document.documentElement.scrollTop;
alert( top);
}
Prevent bubbling
CancelBubble Use e object to prevent
Expand knowledge
onbeforeunload
Code executed when the page is to be closed
/ /This must be written in the form of return and cannot be written as alert
Disable event binding for a link jump
a & gt;
# & lt; a href = "javascript: void (0)" OnClick = "Demo ()" & GT; " onclick="return false">Click me to try

Three ways to bind events in JavaScript and remove binding

Detailed explanation of binding events and unbinding events in js

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