JS获取及设置TextArea或input文本框选择文本位置的方法

function getPos(el) { var range, textRange, duplicate el.focus() if ( el.selectionStart ) return el.selectionStart else if ( document.selection ) { // IE  range = document.selection.createRange()  if ( range == null ) return el.value.length  textRange = el.createTextRange()  duplicate = textRange.duplicate()  textRange.moveToBookmark(range.getBookmark())  duplicate.setEndPoint('EndToStart', textRange)  return duplicate.text.length }}function setPos(el, pos) { var range el.focus() if ( el.setSelectionRange )  el.setSelectionRange(pos, pos) else if ( el.createTextRange ) {  range.collapse(true)  range.moveEnd('character', pos)  range.moveStart('character', pos)  range.select() }}