javascript实现鼠标拖动改变层大小的方法

更新时间：2026-02-18 19:39:21作者：zhao

本文实例讲述了javascript实现鼠标拖动改变层大小的方法。分享给大家供大家参考。具体实现方法如下：

<html>

<head>

<title>拖动改变层的大小</title>

<style> {

box-sizing: border-box; moz-box-sizing: border-box

}

#testDiv { background-color: buttonface; background-repeat: repeat;

background-attachment: scroll; color: #3969A5; height: 300px;

left: 30px; overflow: hidden; width: 500; z-index: 2;

border: 2px outset white; margin: 0px; padding: 2px;

background-position: 0% 50% }

body { font-family: Verdana; font-size: 9pt }

#innerNice { background-color: white; background-repeat: repeat;

background-attachment:

scroll; color: #3969A5; height: 100%; overflow: auto;

width: 100%; border: 2px inset white; padding: 8px;

background-position: 0% 50% }

</style>

var theobject = null;

function resizeObject() {

this.el = null; //pointer to the object

this.dir = ""; //type of current resize (n,s,e,w,ne,nw,se,sw)

this.grabx = null; //Some useful values

this.graby = null;

this.width = null;

this.height = null;

this.left = null;

this.top = null;

}

function getDirection(el) {

var xPos, yPos, offset, dir;

dir = "";

xPos = window.event.offsetX;

yPos = window.event.offsetY;

offset = 8; //The distance from the edge in pixels

if (yPos<offset) dir += "n";

else if (yPos > el.offsetHeight-offset) dir += "s";

if (xPos<offset) dir += "w";

else if (xPos > el.offsetWidth-offset) dir += "e";

return dir;

}

function doDown() {

var el = getReal(event.srcElement, "className", "resizeMe");

if (el == null) {

theobject = null;

return;

}

dir = getDirection(el);

if (dir == "") return;

theobject = new resizeObject();

theobject.el = el;

theobject.dir = dir;

theobject.grabx = window.event.clientX;

theobject.graby = window.event.clientY;

theobject.width = el.offsetWidth;

theobject.height = el.offsetHeight;

theobject.left = el.offsetLeft;

theobject.top = el.offsetTop;

window.event.returnValue = false;

window.event.cancelBubble = true;

}

function doUp() {

if (theobject != null) {

theobject = null;

}

function doMove() {

var el, xPos, yPos, str, xMin, yMin;

xMin = 8; //The smallest width possible

yMin = 8; // height

el = getReal(event.srcElement, "className", "resizeMe");

if (el.className == "resizeMe") {

str = getDirection(el);

//Fix the cursor

if (str == "") str = "default";

else str += "-resize";

el.style.cursor = str;

}

//Dragging starts here

if(theobject != null) {

if (dir.indexOf("e") != -1)

theobject.el.style.width = Math.max(xMin, theobject.width + window.event.clientX - theobject.grabx) + "px";

if (dir.indexOf("s") != -1)

theobject.el.style.height = Math.max(yMin, theobject.height + window.event.clientY - theobject.graby) + "px";

if (dir.indexOf("w") != -1) {

theobject.el.style.left = Math.min(theobject.left + window.event.clientX - theobject.grabx, theobject.left + theobject.width - xMin) + "px";

theobject.el.style.width = Math.max(xMin, theobject.width - window.event.clientX + theobject.grabx) + "px";

}

if (dir.indexOf("n") != -1) {

theobject.el.style.top = Math.min(theobject.top + window.event.clientY - theobject.graby, theobject.top + theobject.height - yMin) + "px";

theobject.el.style.height = Math.max(yMin, theobject.height - window.event.clientY + theobject.graby) + "px";

}

window.event.returnValue = false;

window.event.cancelBubble = true;

}

function getReal(el, type, value) {

temp = el;

while ((temp != null) && (temp.tagName != "BODY")) {

if (eval("temp." + type) == value) {

el = temp;

return el;

}

temp = temp.parentElement;

}

return el;

}

document.onmousedown = doDown;

document.onmouseup = doUp;

document.onmousemove = doMove;

</SCRIPT>

</head>

<body>

请在边框处拖动鼠标</p>

</div>

</body>

</html>

希望本文所述对大家的javascript程序设计有所帮助。