bool? check1 = false; 

​

Checkbox( //only check box

  value: check1, //unchecked

  onChanged: (bool? value){

      //value returned when checkbox is clicked

      setState(() {

          check1 = value;

      });

  }

)

bool isChecked = false;

Checkbox(

              value: isChecked,

              onChanged: (value) {

                setState(() {

                  isChecked = value!;

                });

              },

            ),

CheckboxListTile(

    title: Text("title text"),

    value: checkedValue,

    onChanged: (newValue) { 

                 setState(() {

                   checkedValue = newValue; 

                 }); 

               },

    controlAffinity: ListTileControlAffinity.leading,  //  <-- leading Checkbox

  )

bool _value = true;

​

Checkbox(

  value: _value,

  onChanged: (bool newValue) {

    setState(() {

      _value = newValue;

    });

  },

)