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);  
    }