基于jQuery实现的设置文本区域的光标位置

$.fn.selectRange = function(start, end) { if(end === undefined) { end = start; } return this.each(function() { if('selectionStart' in this) {  this.selectionStart = start;  this.selectionEnd = end; } else if(this.setSelectionRange) {  this.setSelectionRange(start, end); } else if(this.createTextRange) {  var range = this.createTextRange();  range.collapse(true);  range.moveEnd('character', end);  range.moveStart('character', start);  range.select(); } });};

$.fn.setCursorPosition = function(position){ if(this.length == 0) return this; return $(this).setSelection(position, position);}$.fn.setSelection = function(selectionStart, selectionEnd) { if(this.length == 0) return this; input = this[0]; if (input.createTextRange) { var range = input.createTextRange(); range.collapse(true); range.moveEnd('character', selectionEnd); range.moveStart('character', selectionStart); range.select(); } else if (input.setSelectionRange) { input.focus(); input.setSelectionRange(selectionStart, selectionEnd); } return this;}$.fn.focusEnd = function(){ this.setCursorPosition(this.val().length);  return this;}

function setSelectionRange(input, selectionStart, selectionEnd) { if (input.setSelectionRange) { input.focus(); input.setSelectionRange(selectionStart, selectionEnd); } else if (input.createTextRange) { var range = input.createTextRange(); range.collapse(true); range.moveEnd('character', selectionEnd); range.moveStart('character', selectionStart); range.select(); }}function setCaretToPos (input, pos) { setSelectionRange(input, pos, pos);}