code: function(){
        var realValue = this.value;
        realValue = isNaN(realValue) ? 0 : realValue;
        realValue = realValue < options.min ? options.min : realValue;
        realValue = realValue > options.max ? options.max : realValue;
        this.value = realValue;
        var inputScale =  (realValue - options.min) / (options.max - options.min) * 100 / step;
        change(inputScale, 0);
      }
docs: 获取输入框值