JavaScript 获取/设置光标位置,兼容Input&&TextArea

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<!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> <title>JavaScript 获取/设置光标位置,兼容Input&&TextArea。</title> <meta http-equiv="Content-Type" content="text/html; charset=gb2312" /> <style> body { margin: 32px; font-family: Verdana, sans-serif; font-size: 13px; } .title { font-size: 18px; font-weight: bolder;margin:40px 0; } .input { width: 50%; font-family: Verdana, sans-serif; font-size: 13px; text-indent: 2px; } </style> <script> //获取光标位置 //单行文本框 function getPositionForInput(ctrl){ var CaretPos = 0; if (document.selection) { // IE Support ctrl.focus(); var Sel = document.selection.createRange(); Sel.moveStart('character', -ctrl.value.length); CaretPos = Sel.text.length; }else if(ctrl.selectionStart || ctrl.selectionStart == '0'){// Firefox support CaretPos = ctrl.selectionStart; } return (CaretPos); } //多行文本框 function getPositionForTextArea(ctrl) { var CaretPos = 0; if(document.selection) {// IE Support ctrl.focus(); var Sel = document.selection.createRange(); var Sel2 = Sel.duplicate(); Sel2.moveToElementText(ctrl); var CaretPos = -1; while(Sel2.inRange(Sel)){ Sel2.moveStart('character'); CaretPos++; } }else if(ctrl.selectionStart || ctrl.selectionStart == '0'){// Firefox support CaretPos = ctrl.selectionStart; } return (CaretPos); } //设置光标位置函数 function setCursorPosition(ctrl, pos){ if(ctrl.setSelectionRange){ ctrl.focus(); ctrl.setSelectionRange(pos,pos); } else if (ctrl.createTextRange) { var range = ctrl.createTextRange(); range.collapse(true); range.moveEnd('character', pos); range.moveStart('character', pos); range.select(); } } //test function process( id,targetId ){ var no = document.getElementById(id).value; setCursorPosition(document.getElementById(targetId),no); } </script> </head> <body> <div class="title">JavaScript 获取/设置光标位置,兼容Input&&TextArea：</div> <div class="title">单行文本框</div> <p><input class="input" id="textbox" name="textbox" value="Hi,www.jb51.net!!!" /></p> <input type="button" onclick="alert( getPositionForInput( document.getElementById('textbox') ) )" value="Get Position"> 输入位置: <input type="text" id="no1" size="1" /><input type="button" onclick="process('no1','textbox');" value="Set Position"> <div class="title">多行文本框</div> <textarea id="zhangdanNum" name="zhangdanNum" style="height:66px;width:246px;overflow:hidden">Hi,CssRain!!!</textarea> <input type="button" onclick="alert( getPositionForTextArea( document.getElementById('zhangdanNum') ) )" value="Get Position"> 输入位置: <input type="text" id="no2" size="1" /><input type="button" onclick="process('no2','zhangdanNum');" value="Set Position"> </body> </html>