正文
js笔记---拖动元素
提示：扫一扫查出行【扫一扫了解最新限行尾号】
复制提示
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title></title>
<style>
#img1 { position: absolute; }
</style>
<script type="text/javascript">
window.onload = function () {
var oImg = document.getElementById('img1');
drop(oImg);
}
function drop(obj) {
obj.onmousedown = function (ev) {
var ev = ev || event;
var liw = ev.clientX - parseInt(getStyle(obj, 'left') == 'auto' ? '0' : getStyle(obj, 'left'));
var lit = ev.clientY - parseInt(getStyle(obj, 'top') == 'auto' ? '0' : getStyle(obj, 'top'));
if (obj.getCaptrue) {
obj.getCaptrue();
}
document.onmousemove = function (ev) {
var ev = ev || event;
var L = ev.clientX - liw;
var T = ev.clientY - lit;
if (L < 100) {
L = 0;
}
if (L > document.documentElement.clientWidth - obj.offsetWidth-100) {
L = (document.documentElement.clientWidth - obj.offsetWidth);
}
if (T < 100) {
T = 0;
}
if (T > document.documentElement.clientHeight - obj.offsetHeight - 100) {
T = (document.documentElement.clientHeight - obj.offsetHeight);
}
obj.style.left = L + 'px';
obj.style.top = T + 'px';
}
document.onmouseup = function () {
document.onmousemove = document.onmouseup = null;
if (obj.relaseCaptrue) {
obj.relaseCaptrue();
}
}
return false;
}
}
function getStyle(obj, attr) {
if (obj.currentStyle) {
return obj.currentStyle[attr];
} else {
return getComputedStyle(obj, false)[attr];
}
}
</script>
</head>
<body>
<img src="data:images/btn_04.jpg" id="img1" />
<!--<img src="data:images/btn_02.jpg" />-->
</body>
</html>
