拖拽
作者：互联网
<!DOCTYPE html>
<html lang="zh-CN">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no">
<title>2.4 单指拖拽--拖拽</title>
<style>
body {
height: 2000px;
}
.backtop {
position: fixed;
right: 20px;
bottom: 20px;
width: 45px;
height: 45px;
line-height: 45px;
text-align: center;
background-color: rgba(0, 0, 0, 0.6);
border-radius: 50%;
color: #fff;
font-size: 30px;
-webkit-tap-highlight-color: transparent;
/*transform: translate3d(x, y, 0);*/
}
</style>
</head>
<body>
<a href="#" id="backtop" class="backtop">↑</a>
<script> function drag(el, options) { options.x = typeof options.x !== 'undefined' ? options.x : true; options.y = typeof options.y !== 'undefined' ? options.y : false;
if (!options.x && !options.y) return;
var curPoint = { x: 0, y: 0 }; var startPoint = {}; var isTouchMove = false;
el.addEventListener('touchstart', handleStart, false); el.addEventListener('touchmove', handleMove, false); el.addEventListener('touchend', handleEnd, false);
function handleStart(ev) { var touch = ev.changedTouches[0];
startPoint.x = touch.pageX; startPoint.y = touch.pageY; } function handleMove(ev) { ev.preventDefault();
isTouchMove = true;
var touch = ev.changedTouches[0]; var diffPoint = {}; var movePoint = { x: 0, y: 0 };
diffPoint.x = touch.pageX - startPoint.x; diffPoint.y = touch.pageY - startPoint.y;
if (options.x) { movePoint.x = diffPoint.x + curPoint.x; } if (options.y) { movePoint.y = diffPoint.y + curPoint.y; } move(el, movePoint.x, movePoint.y); } function handleEnd(ev) { if (!isTouchMove) return;
var touch = ev.changedTouches[0];
curPoint.x += touch.pageX - startPoint.x; curPoint.y += touch.pageY - startPoint.y;
isTouchMove = false; }
function move(el, x, y) { x = x || 0; y = y || 0;
el.style.transform = 'translate3d(' + x + 'px, ' + y + 'px, 0)'; } } </script> <script> var backtop = document.getElementById('backtop'); drag(backtop, { x: true, y: true }); </script> </body> </html>
<script> function drag(el, options) { options.x = typeof options.x !== 'undefined' ? options.x : true; options.y = typeof options.y !== 'undefined' ? options.y : false;
if (!options.x && !options.y) return;
var curPoint = { x: 0, y: 0 }; var startPoint = {}; var isTouchMove = false;
el.addEventListener('touchstart', handleStart, false); el.addEventListener('touchmove', handleMove, false); el.addEventListener('touchend', handleEnd, false);
function handleStart(ev) { var touch = ev.changedTouches[0];
startPoint.x = touch.pageX; startPoint.y = touch.pageY; } function handleMove(ev) { ev.preventDefault();
isTouchMove = true;
var touch = ev.changedTouches[0]; var diffPoint = {}; var movePoint = { x: 0, y: 0 };
diffPoint.x = touch.pageX - startPoint.x; diffPoint.y = touch.pageY - startPoint.y;
if (options.x) { movePoint.x = diffPoint.x + curPoint.x; } if (options.y) { movePoint.y = diffPoint.y + curPoint.y; } move(el, movePoint.x, movePoint.y); } function handleEnd(ev) { if (!isTouchMove) return;
var touch = ev.changedTouches[0];
curPoint.x += touch.pageX - startPoint.x; curPoint.y += touch.pageY - startPoint.y;
isTouchMove = false; }
function move(el, x, y) { x = x || 0; y = y || 0;
el.style.transform = 'translate3d(' + x + 'px, ' + y + 'px, 0)'; } } </script> <script> var backtop = document.getElementById('backtop'); drag(backtop, { x: true, y: true }); </script> </body> </html>
标签：el,options,var,touch,ev,startPoint,拖拽 来源： https://www.cnblogs.com/eric-share/p/16334537.html