Dalam artikel ini, kita akan membincangkan secara terperinci tentang Atribut Acara HTML. Peristiwa ialah tindakan yang dilakukan sebagai hasil daripada tindakan pengguna. Sebagai contoh, apabila pengguna menekan papan kekunci untuk membaca data, ia dikatakan sebagai peristiwa papan kekunci. Aktiviti ini dilakukan apabila pengguna melihat ke dalam laman web dan melakukan klik butang atau apabila halaman dimuatkan dengan menekan butang muat semula di mana penyemak imbas melakukan manipulasi pada halaman; semua tindakan ini dikatakan sebagai satu peristiwa. Di sini kita akan melalui pemahaman asas tentang peristiwa dan cara ia berfungsi dalam penyemak imbas pada tindakan pengguna. Terdapat jenis peristiwa berbeza yang berlaku dalam keseluruhan tetingkap penyemak imbas yang dijelaskan dalam bahagian berikut.
Terdapat variasi acara berbeza yang tersedia dalam HTML. Dan semua acara ini mempunyai blok kecil kod yang dinamakan sebagai pengendali acara yang menyala apabila tindakan acara dilakukan. Ini dilampirkan pada elemen HTML. Pengendali acara atau pendengar acara memainkan peranan penting dalam atribut acara HTML. Mari lihat pelbagai jenis atribut acara yang diisytiharkan secara global dan digunakan pada elemen HTML serta kerja mereka secara terperinci. Empat atribut acara utama digunakan secara besar-besaran. Mereka ialah:
Kami akan menerangkan semua sifat ini satu persatu dengan contoh. Mula-mula, kita akan ikut.
Kod:
<!DOCTYPE html>
<html>
<head>
<title>
Windows onafterprint Event
</title>
</head>
<body onafterprint="myfun()">
<h1>Windows onafterprint Event </h1>
<p>This attribute works in IE and Mozilla</p>
<body style = "text-align:center">
<script>
function myfun() {
alert("Document is being printed");
}
</script>
</body>
</html>Output:
Kod:
<!DOCTYPE html>
<html>
<head>
<style>
body {
color: #9370DB;
background-color: #BC8F8F;
text-align: center;
padding: 20px;
}
p {
font-size: 2rem;
}
</style>
</head>
<body onbeforeprint="get()">
<h1> Attribute Demo</h1>
<p style="color:#0000FF;">trigger to print.</p>
<div class="show"></div>
<script>
function get() {
document.body.style.background = "#00BFFF";
}
</script>
</body>
</html>Output:
Kod:
<!DOCTYPE html>
<html>
<body>
<img src="p.jpg" onerror="myFun()">
<p>hello world.</p>
<script>
function myFun() {
alert("problem with image loading.");
}
</script>
</body>
</html>Output:
Kod:
<!DOCTYPE html>
<html>
<head>
<title>onload event demo</title>
</head>
<body>
<img src="pic.jpg" onload="ldImg()" width="50" height="92">
<script>
function ldImg() {
alert("image loaded without error");
}
</script>
</body>
</html>Output:
Kod:
<!DOCTYPE html>
<head>
<title>onresize event</title>
</head>
<body>
<script type="text/javascript">
function cmg() {
alert('welcome to educba');
}
window.onresize = cmg;
</script>
</head>
<body>
<input type="button" value="Click the button"
onclick="alert(window.onresize);">
</body>
</html>Output:
Kod:
<!DOCTYPE html>
<html>
<body onunload="onfunc()"><h1>Welcometo educba tutorial</h1>
<p>Leave the page .</p>
<script>
function onfunc() {
alert("Thank you for searching!");
}
</script>
</body>
</html>Output:
Ia berfungsi dengan Kawalan borang. Berikut ialah atribut yang berlaku apabila pengguna berinteraksi dengan penyemak imbas.
Kod:
<!DOCTYPE html>
<html>
<head>
<title> Form onblur </title>
<style>
body {
text-align:center;
}
h1 {
color:pink;
}
</style>
</head>
<body>
<h1>EDUCBA</h1>
<input type="text" name="fname" id="aaa"
onblur="myfunc()">
<button type="button">Submit</button>
<script>
function myfunc() {
var a = document.getElementById("aaa");
a.value = a.value.toUpperCase();
}
</script>
</body>
</html>Output:
Kod:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>HTML onchange</title>
</head>
<body>
<form name="example" action=""> <input type="text" name="rahul" onchange="alert('input is changed')"><br>
<label>select the dress color</label>
<select onchange="alert('You have changed the selection!');">
<option>pink</option>
<option>Yellow</option>
<option>White</option>
</select>
<p><strong>Note:</strong> Select any option </p>
<label>Describe yourself in short : </label> <br/><textarea cols="15" rows="7" name="details" onchange="alert('description has changed')"> </textarea><br>
<button type="button" name="submit">Submit</button>
</form>
</body>
</html>Output:
Kod:
<!DOCTYPE html>
<html>
<body>
<p>This event gets triggered whwn an element is been focussed.</p>
Name: <input type="text" id="name" onfocus="onfoc(this.id)"><br>
Location: <input type="text" id="loc" onfocus="onfoc(this.id)">
<script>
function onfoc(a) {
document.getElementById(a).style.background = "pink";
}
</script>
</body>
</html>Output:
<!DOCTYPE html>
<html>
<head>
<title> HTML oninput </title>
</head>
<style>
body {
text-align:center;
}
h1 {
color:red;
}
</style>
<body>
<h1> Event Attribute </h1>
Enter the text:
<input type="text" id="EDUCBA" oninput="myon()">
<p id= "sid"></p>
<script>
function myon()
{
var x = document.getElementById("EDUCBA").value;
document.getElementById("sid").innerHTML = "Enter the text : " +x;
}
</script>
</body>
</html>Output:
Code:
<!DOCTYPE html>
<html>
<head>
<title> example oninvalid Event </title>
<style>
p {
color:orange;
}
body {
text-align:center;
}
</style> </head>
<body>
<p> HTML is used to create a web page</p>
<form method="get">
Enter the name:
<input type="text" oninvalid="alert('Fill the text form!');" required>
<input type="submit" value="Submit">
</form> </body>
</html>Output:
Code:
<!DOCTYPE html>
<html>
<style>
body {font-family:calibri;}
label {font-variant:small-caps;}
ol {background-color:#610000; margin-top:35px;}
li {margin-top:3px; padding:3px; background-color:rose; font-size:15px;}
div {position:absolute;top:250px;left:70px; font-size:1.5em;
}
</style>
<body>
<ol>
<li>Form with input to reset and submit</li>
</ol>
<form action="" method="get" onreset="onRes()" onsubmit="onSub()">
<label>Enter input:<br /><input type="text" id="iv" oninvalid="onInva()" oninput="onInp()"></label><br /><br />
<input type="submit" value="press"> <input type="reset">
</form>
<div id="a_box"></div>
<script>
function onInva() {
alert("Input field cannot be empty!");
}
function onInp() {
var input_value = document.getElementById("iv").value;
document.getElementById("a_box").innerHTML = "Input value: <br />" + iv;
}
function onRes() {
alert("form is reset!");
}
function onSubmitEvent() {
alert("Form is loading");
location.reload();
}
</script>
</body>
</html>Output:
Code:
<!DOCTYPE html>
<html>
<body>
<p>Write in the field.</p>
<input type="search" id="value1" onsearch="myF()">
<p id="sample"></p>
<script>
function myF() {
var k = document.getElementById("value1");
document.getElementById("sample").innerHTML = "search element is: " + k.value;
}
</script>
</body>
</html>Output:
Code:
<!DOCTYPE html>
<html>
<head>
<title>onselect demo</title>
<style>
h1 {
color:magenta;
}
body {
text-align:center;
}
</style>
<script>
function eduhtml() {
alert("text highlighted!");
}
</script>
</head>
<body>
<h1>EDUCBA Online tutorial</h1>
Text Box: <input type="text" value="onselectattribute: A well defined portal" onselect="eduhtml()">
</body>
</html>
</html>Output:
Code:
<!DOCTYPE html>
<html>
<body>
<head>
<title> Onsubmit Example</title>
</head>
<form action="demo_form.asp" onsubmit="myF()">
Enter name: <input type="text" name="fname">
<label>Email :</label>
<input id="email" name="email" type="text">
<input type="submit" value="Submit">
</form>
<script>
function myF() {
alert("The form was submitted");
}
</script>
</body>
</html>Output:
Code:
<!DOCTYPE html>
<html>
<body>
<p>Example for Onkeydown.</p>
<input type="text" onkeydown="mykedwn()">
<script>
function mykedwn() {
alert("key press is activated");
}
</script>
</body>
</html>Output:
Code:
<!DOCTYPE html>
<html>
<body>
<p> This example shows when a user type in the text area it triggers an event </p>
<form>
<textarea onkeypress="alert('triggering onkeypress event.')" placeholder="Place the cursor inside the textarea and press a key." " cols="30" rows="4" style="background-color:pink;">> </textarea> </form>
</body>
</html>Output:
Code:
<!DOCTYPE html>
<html>
<body>
<p> This example transforms the character to lower case.</p>
Fill the name: <input type="text" id="jjj" onkeyup="mykey()">
<script>
function mykey() {
var g = document.getElementById("jjj");
g.value = g.value.toLowerCase();
}
</script>
</body>
</html>Output:
This action triggers a mouse event when a mouse is pressed either from a computer or any external devices like a smartphone or tablet. Some of the mouse events are given below:
Code:
<!DOCTYPE html>
<html>
<body>
<h1>HTML onclick Event</h1>
<p> Event plays a vital role in HTML.</p>
<button onclick="oncf()">Click </button>
<p id="sample"></p>
<script>
function oncf() {
document.getElementById("sample").innerHTML = "Hello World";
}
</script>
</body>
</html>Output:
Code:
<!doctype html>
<html>
<head><title> Event onmousemove demo</title>
</head>
<body>
<p>This event is activated when the pointer drags its direction.</p>
<body style="width:200px;height:80px;border:2px solid;" onmousemove="javascript:alert('mouse action');">Sample text</body>
</body>
</html>Output:
Code:
<!DOCTYPE html>
<html>
<head>
<style>
body {
color: "#ff0000";
height: 120vh;
background-color: #610000;
text-align: center;
}
.polygon {
float: right;
shape-inside: polygon(0 0, 0 200px, 100px 200px);
clip-path: polygon(0 0, 0 250px, 100px 300px);
height: 200px;
width: 200px;
background: linear-gradient(to bottom left, #7CFC00, #8B008B);
}
p {
margin: 30px auto;
}
</style>
</head>
<body>
<h1>HTML onmouseup Demo</h1>
<div class="polygon" onmouseup="mupfn()"></div>
<p> click below object</p>
<script>
function mupFn() {
document.querySelector('.polygon').style.transform = 'scale(2.2)';
}
</script>
</body>
</html>Output:
Code:
<!DOCTYPE html>
<html>
<body>
<title>Example demonstrating Onmouseover.</title>
<h1 id="sample" onmouseover="A()" onmouseout="B()">Mouse over </h1>
<script>
function A() {
document.getElementById("sample").style.color = "yellow";}
function B() {
document.getElementById("sample").style.color = "green";
}
</script>
</body>
</html>Output:
This application helps in the HTML window when the user drags the input element. Below are the different event listeners used in HTML to store dragged data.
Code:
<!DOCTYPE HTML>
<html>
<head>
<style type = "text/css">
#b1, #b2 {
float:left;padding:11px;margin:11px; -moz-user-select:none;
}
#b1 { background-color: #FF6699; width:65px; height:85px; }
#b2 { background-color: #808000; width:180px; height:180px; }
</style>
<script type = "text/javascript">
function dStart(e) {
e.dataTransfer.effectAllowed = 'move';
e.dataTransfer.setData("Text", e.target.getAttribute('id'));
e.dataTransfer.setDragImage(e.target,0,0);
return true;
}
</script>
</head>
<body>
<center>
<h2>Drag demo</h2>
<div> Drag the box.</div>
<div id = "b1" draggable = "true"
ondragstart = "return dStart(e)">
<p>Drag it</p>
</div>
<div id = "b2">welcome</div>
</center>
</body>
</html>Output:
Code:
<!DOCTYPE HTML>
<html>
<head>
<style type = "text/css">
#b1, #b2 {
float:left;padding:11px;margin:11px; -moz-user-select:none;
}
#b1 { background-color: #FF6699; width:65px; height:85px; }
#b2 { background-color: #808000; width:180px; height:180px; }
</style>
<script type = "text/javascript">
function dStart(e) {
e.dataTransfer.effectAllowed = 'move';
e.dataTransfer.setData("Text", e.target.getAttribute('id'));
e.dataTransfer.setDragImage(e.target,0,0);
return true;
}
</script>
</head>
<body>
<center>
<h2>Drag dropdemo</h2>
<div> drop the box.</div>
<div id = "b1" draggable = "true"
ondragstart = "return dStart(e)">
<p>Drag it</p>
</div>
<div class="droptarget"
ondrop="drop(event)"
ondragover="allowDrop(event)">
</div>
<div id = "b2">welcome</div>
<span> dropzone </span>
</center>
</body>
</html>Output:
This event attribute helps to make a web application very easier and attractive. The different occurrence of actions generates various events. Even though this approach is generally avoided, the programmer likes to learn the function assigned for the HTML attributes events. These event handlers are still executed to beautify the web pages.
This is a guide to the HTML Event Attributes. Here we discuss the Introduction to HTML Event Attributes along with Code implementation and Output. you can also go through our suggested articles to learn more –
Atas ialah kandungan terperinci Atribut Acara HTML. Untuk maklumat lanjut, sila ikut artikel berkaitan lain di laman web China PHP!
![[Web front-end] Permulaan pantas Node.js](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
