jQuery 文本框 光标 移动到 文字最后

方法一：调用办法：setCaretToPos(document.getElementById("YOURINPUT"), 4);

     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);
     }  

方法二：调用办法：$('#elem').selectRange(3,5);

     $.fn.selectRange = function(start, end) {
         return this.each(function() {
             if (this.setSelectionRange) {
                 this.focus();
                 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();
             }
         });
     };  

方法三：调用办法：$(element).focusEnd();

     $.fn.setCursorPosition = function(position){
         if(this.lengh == 0) return this;
         return $(this).setSelection(position, position);
     }  

     $.fn.setSelection = function(selectionStart, selectionEnd) {
         if(this.lengh == 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);
     }