js method to implement the up, down, left, and right keys of the keyboard to select text and display it in the text box

js method to implement the up, down, left, and right keys of the keyboard to select text and display it in the text box_javascript skills

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Release： 2016-05-16 16:00:33

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The example in this article describes the js method of implementing the up, down, left, and right keys on the keyboard to select text and display it in the text box. Share it with everyone for your reference. The specific implementation method is as follows:

<!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>SimulateUpDownKeySelect.html</title>
<style type="text/css">
#divSelect {border:1px solid red; width:208px !important;width:210px;}
#divSelect ul {width:200px;margin:3px; margin-left:-35px;*margin-left:3px;overflow:hidden}
#divSelect ul li {float:left; list-style-type:none;width:45px;height:14px;line-height:20px;font:14px arial;text-align:center;padding:2px}
#divSelect li:hover {background :green;cursor:pointer}
#txtInput {width:205px;}
</style>
 </head>
 <body>
<form method="post" action="##">
<input type="text" id="txtInput" value="" autocomplete="off" onkeydown="if(event.keyCode==13)return false;" />
<!--
防止回车键触发表单提交
onKeyPress
-->
<div id="divSelect">
</div>
<script type="text/javascript">
var list="<ul>"
list+="<li>科幻片</li><li>战争片</li><li>动作片</li><li>爱情片</li><li>剧情片</li><li>记录片</li><li>综艺片</li><li>喜剧片</li><li>动画片</li><li>励志片</li><li>恐怖片</li><li>古装片</li><li>电视剧</li><li>读书</li><li >小说</li><li>作品集</li><li>历史</li><li>诗歌</li><li >散文</li><li>军事</li>";
list+="</ul>"
document.getElementById('divSelect').innerHTML=list;
</script>
</form>
<script type="text/javascript">
<!--
function $(sId)
{
  return document.getElementById(sId);
}
function clearSelectedOptBgColor(target)
{
  if (target.seletedIndex >= 0)
    target.options[target.seletedIndex].style.background = "";
}
function setSelectedOptBgColor(target)
{
  target.options[target.seletedIndex].style.background = "green";
}
var upKeyCode = 38;
var downKeyCode = 40;
var enterKeyCode = 13;
var oInput = $("txtInput");
oInput.options = $("divSelect").getElementsByTagName("li");
oInput.seletedIndex = -1;
oInput.focus();
//oInput.onKeyPress{}
oInput.onkeyup = function(event){
  if (event == undefined)
    event = window.event;
  switch (event.keyCode)
  {
    case 37:
      clearSelectedOptBgColor(this);
      this.seletedIndex--;
      if (this.seletedIndex < 0)
        this.seletedIndex = this.options.length - 1;
 this.value = this.options[this.seletedIndex].innerHTML;
      setSelectedOptBgColor(this);
      break;
      case 38:
      clearSelectedOptBgColor(this);
      this.seletedIndex= this.seletedIndex-4;
      if (this.seletedIndex < 0)
        this.seletedIndex = this.options.length - 1;
 this.value = this.options[this.seletedIndex].innerHTML;
      setSelectedOptBgColor(this);
      break;
    case 39:
      clearSelectedOptBgColor(this);
      this.seletedIndex++;
      if (this.seletedIndex >= this.options.length)
        this.seletedIndex = 0;
      this.value = this.options[this.seletedIndex].innerHTML;
      setSelectedOptBgColor(this);
      break;
      case 40:
      clearSelectedOptBgColor(this);
      this.seletedIndex= this.seletedIndex+4;
      if (this.seletedIndex >= this.options.length)
        this.seletedIndex = 0;
      this.value = this.options[this.seletedIndex].innerHTML;
      setSelectedOptBgColor(this);
      break;
     case enterKeyCode:
      this.value = this.options[this.seletedIndex].innerHTML;
      //alert('aa')
      break;
  }
};
oInput.onblur = function(){
  clearSelectedOptBgColor(this);
  this.seletedIndex = 1;
};
//-->
</script>
</body>
</html>

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I hope this article will be helpful to everyone’s JavaScript programming design.