The following FormatException was thrown while calling onChanged: Invalid number (at character 1)

I am trying to clear the initial value from and textfield and give new value, when the textfield is empty i am getting this error.

The following FormatException was thrown while calling onChanged:
Invalid number (at character 1)

^

When the exception was thrown, this was the stack: 
#0      int._handleFormatError (dart:core-patch/integers_patch.dart:129:7)
#1      int.parse (dart:core-patch/integers_patch.dart:55:14)

Below is my code.

  int _currentSliderValue = 1;
  TextEditingController sliderController = TextEditingController();

Column(
            children: [
              Slider(
                value: _currentSliderValue.toDouble(),
                max: 100,
                label: _currentSliderValue.round().toString(),
                onChanged: (double value) {
                  setState(() {
                    _currentSliderValue = value.toInt();
                    sliderController.text = _currentSliderValue.toString();
                    print(_currentSliderValue);
                  });
                },
              ),
              Padding(
                padding: const EdgeInsets.all(0.0),
                child: TextFormField(
                  decoration: InputDecoration(
                    border: OutlineInputBorder(),
                  ),
                  controller: sliderController,
                  onChanged: (text) {
                    setState(() {
                      _currentSliderValue = int.parse(text);
                    });
                  },
                ),
              ),
            ],
          )

How to overcome this issue. i don't get any error when i add any values.

Please help me how to fix this. Thanks in advance.

This error occurs because the int parser couldn't parse the string you're trying to parse. To fix this you should make sure that the value is correct or use int.tryParse(value).