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JS实现用键盘控制DIV

2015-03-04 15:01 573 查看
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">

<head>

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

<title>用键盘控制DIV</title>

<style type="text/css">

html,body{overflow:hidden;}

body{margin:0;padding:0;}

pre{color:green;padding:10px 15px;background:#f0f0f0;border:1px dotted #333;font:12px/1.5 Courier New;margin:12px;}

span{color:#999;}

#box{position:absolute;top:50px;left:300px;width:100px;height:100px;background:red;}

</style>

<script type="text/javascript">

window.onload = function ()

{

var oBox = document.getElementById("box");

var bLeft = bTop = bRight = bBottom = bCtrlKey = false;

setInterval(function ()

{

if (bLeft)

{

oBox.style.left = oBox.offsetLeft - 10 + "px"

}

else if (bRight)

{

oBox.style.left = oBox.offsetLeft + 10 + "px"

}

if (bTop)

{

oBox.style.top = oBox.offsetTop - 10 + "px"

}

else if(bBottom)

{

oBox.style.top = oBox.offsetTop + 10 + "px"

}

//防止溢出

limit();

},30);

document.onkeydown = function (event)

{

var event = event || window.event;

bCtrlKey = event.ctrlKey;

switch (event.keyCode)

{

case 37:

bLeft = true;

break;

case 38:

if(bCtrlKey)

{

var oldWidth = oBox.offsetWidth;

var oldHeight = oBox.offsetHeight;

oBox.style.width = oBox.offsetWidth * 1.5 + "px";

oBox.style.height = oBox.offsetHeight * 1.5 + "px";

oBox.style.left = oBox.offsetLeft - (oBox.offsetWidth - oldWidth) / 2 + "px";

oBox.style.top = oBox.offsetTop - (oBox.offsetHeight - oldHeight) / 2 + "px";

break;

}

bTop = true;

break;

case 39:

bRight = true;

break;

case 40:

if(bCtrlKey)

{

var oldWidth = oBox.offsetWidth;

var oldHeight = oBox.offsetHeight;

oBox.style.width = oBox.offsetWidth * 0.75 + "px";

oBox.style.height = oBox.offsetHeight * 0.75 + "px";

oBox.style.left = oBox.offsetLeft - (oBox.offsetWidth - oldWidth) / 2 + "px";

oBox.style.top = oBox.offsetTop - (oBox.offsetHeight - oldHeight) / 2 + "px";

break;

}

bBottom = true;

break;

case 49:

bCtrlKey && (oBox.style.background = "green");

break;

case 50:

bCtrlKey && (oBox.style.background = "yellow");

break;

case 51:

bCtrlKey && (oBox.style.background = "blue");

break;

}

return false

};

document.onkeyup = function (event)

{

switch ((event || window.event).keyCode)

{

case 37:

bLeft = false;

break;

case 38:

bTop = false;

break;

case 39:

bRight = false;

break;

case 40:

bBottom = false;

break;

}

};

//防止溢出

function limit()

{

var doc = [document.documentElement.clientWidth, document.documentElement.clientHeight]

//防止左侧溢出

oBox.offsetLeft <=0 && (oBox.style.left = 0);

//防止顶部溢出

oBox.offsetTop <=0 && (oBox.style.top = 0);

//防止右侧溢出

doc[0] - oBox.offsetLeft - oBox.offsetWidth <= 0 && (oBox.style.left = doc[0] - oBox.offsetWidth + "px");

//防止底部溢出

doc[1] - oBox.offsetTop - oBox.offsetHeight <= 0 && (oBox.style.top = doc[1] - oBox.offsetHeight + "px")

}

};

</script>

</head>

<body>

<pre>

红色方块为键盘操作区域,您可以进行如下操作:

上:↑ 下:↓ 左:← 右:→

Ctrl + 1 : 背景变为绿色

Ctrl + 2 : 背景变为黄色

Ctrl + 3 : 背景变为蓝色

Ctrl + ↑ : 放大

Ctrl + ↓ : 缩小

</pre>

<div id="box"></div>

<div><A href="http://www.999jiujiu.com/">http://www.999jiujiu.com/</A></div>

</body>

</html>
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