拖拽效果
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>拖拽效果</title>
<style>
div{200px;height: 200px;background: cyan;position: absolute;}
</style>
<script>
window.onload = function(){
var oDiv = document.getElementById('div1');
//鼠标按下
oDiv.onmousedown = function(ev){
var e = ev || window.event;
//在鼠标按下是计算坐标
//offsetX或Y是鼠标相对于移动物体左上角的坐标
var offsetX = e.clientX - oDiv.offsetLeft;
var offsetY = e.clientY - oDiv.offsetTop;
//鼠标移动效果
document.onmousemove = function(ev){
var e = ev || window.event;
oDiv.style.left = e.clientX - offsetX +'px';
oDiv.style.top = e.clientY - offsetY +'px';
}
}
//鼠标抬起
document.onmouseup = function(){
document.onmousemove = null;
}
}
</script>
</head>
<body>
<div id="div1"></div>
</body>
</html>
浏览器效果：
把上面的拖拽效果封装成函数：
代码如下：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>拖拽效果</title>
<style>
div{200px;height: 200px;background: cyan;position: absolute;}
</style>
<script>
window.onload = function(){
var oDiv = document.getElementById('div1');
drag(oDiv);
}
/*------------封装拖拽函数------------*/
function drag(node){
////offsetX或Y用于存取鼠标相对于移动物体左上角的坐标
var offsetX = 0;
var offsetY = 0;
//鼠标按下
node.onmousedown = function(ev){
var e = ev || window.event;
//在鼠标按下是计算坐标
//offsetX或Y是鼠标相对于移动物体左上角的坐标
offsetX = e.clientX - this.offsetLeft;
offsetY = e.clientY - this.offsetTop;
//鼠标移动效果
document.onmousemove = function(ev){
var e = ev || window.event;
node.style.left = e.clientX - offsetX +'px';
node.style.top = e.clientY - offsetY +'px';
}
}
//鼠标抬起
document.onmouseup = function(){
document.onmousemove = null;
}
}
/*------------封装拖拽函数end------------*/
</script>
</head>
<body>
<div id="div1"></div>
</body>
</html>
浏览器效果与上面相同;
把封装好的函数（如下）说明：
//形参node为元素节点
//调用格式为 drag(元素节点);
/*------------封装拖拽函数------------*/ //形参node为元素节点 //调用格式为 drag(元素节点); function drag(node){ ////offsetX或Y用于存取鼠标相对于移动物体左上角的坐标 var offsetX = 0; var offsetY = 0; //鼠标按下 node.onmousedown = function(ev){ var e = ev || window.event; //在鼠标按下是计算坐标 //offsetX或Y是鼠标相对于移动物体左上角的坐标 offsetX = e.clientX - this.offsetLeft; offsetY = e.clientY - this.offsetTop; //鼠标移动效果 document.onmousemove = function(ev){ var e = ev || window.event; node.style.left = e.clientX - offsetX +'px'; node.style.top = e.clientY - offsetY +'px'; } } //鼠标抬起 document.onmouseup = function(){ //主动调用鼠标移动事件对象函数（方法） document.onmousemove = null; } } /*------------封装拖拽函数end------------*/