標籤：time nbsp 輸入 tom div移動 tps 改變 css 問題
問題版本代碼如下：
1 <html> 2 <head> 3 <title>鍵盤控制div移動</title> 4 <meta charset="utf-8" /> 5 <style type="text/css"> 6 #div1{width:100px;height:100px;background:#ff0000;position:absolute;} 7 </style> 8 <script type="text/javascript"> 9 window.onload = function(){10 var oDiv = document.getElementById("div1");11 document.onkeydown = function(ev){12 var ev = ev || event;13 var keyCode = ev.keyCode;14 switch(keyCode){15 case 37: oDiv.style.left = oDiv.offsetLeft-10+"px";break;16 case 38: oDiv.style.top = oDiv.offsetTop-10+"px";break;17 case 39: oDiv.style.left = oDiv.offsetLeft+10+"px";break;18 case 40: oDiv.style.top = oDiv.offsetTop+10+"px";break;19 }20 }21 22 }23 </script>24 </head>25 <body>26 <div id="div1"></div>27 </body>28 </html>
問題描述：用js的鍵盤事件控制一個div移動，當按下一個方向鍵不放，div會先停頓一下，然後才開始持續移動。（原因：系統要區分使用者是否連續輸入，第一個到第二個之間有一個停頓時間）
解決方案：先開一個定時器，讓div一直處於（往4個方向）準備移動的狀態（初始4個方向的值都是false，div就保持在原地不動），當按下某個方向鍵，這個方向的值就改變為true，div就會開始往這個方向移動，鬆開方向鍵，這個方向的值就改變為false , div就停止這個方向移動了。
解決版本代碼如下：
<html><head><title>鍵盤控制div移動，解決停頓問題</title><meta charset="utf-8" /><style type="text/css">#div1{width:100px;height:100px;background:#ff0000;position:absolute;}</style><script type="text/javascript">window.onload = function(){ var oDiv = document.getElementById("div1"); var timer = null; var left = false; var right = false; var top = false; var bottom = false; setInterval(function(){ if(left){ oDiv.style.left = oDiv.offsetLeft-10+"px"; }else if(top){ oDiv.style.top = oDiv.offsetTop-10+"px"; }else if(right){ oDiv.style.left = oDiv.offsetLeft+10+"px"; }else if(bottom){ oDiv.style.top = oDiv.offsetTop+10+"px"; } },50); document.onkeydown = function(ev){ var ev = ev || event; var keyCode = ev.keyCode; switch(keyCode){ case 37: left = true;break; case 38: top = true;break; case 39: right = true;break; case 40: bottom = true;break; } } document.onkeyup = function(ev){ var ev = ev || event; var keyCode = ev.keyCode; switch(keyCode){ case 37: left = false;break; case 38: top = false;break; case 39: right = false;break; case 40: bottom = false;break; } }}</script></head><body><div id="div1"></div></body></html>
轉自 https://www.cnblogs.com/liujin0505/p/4383015.html
js鍵盤控制div移動，解決停頓問題
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