JS实现用键盘控制DIV上下左右+放大缩小与变色

JS实现用键盘控制DIV上下左右+放大缩小与变色_布局与层

WBOY

Freigeben： 2016-05-16 17:45:32

Original

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用键盘控制DIV，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

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> 
 
 
<div class="code" style="position:relative; padding:0px; margin:0px;"><pre class="brush:php;toolbar:false"> 
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 class="contentsignin">Nach dem Login kopieren</div></div> 
<div id="box"></div>

[Ctrl+A 全选注:如需引入外部Js需刷新才能执行]