How to do something when a checkbox change state?

Question

This is my code:

Answer 1

I believe a RadioButton would be more suitable for your aims.

<RadioGroup
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical"
    android:id="@+id/radio_group1">
    <RadioButton
        android:id="@+id/sprint"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/rad_option1"
        android:checked="true"
    android:onClick="onRadioButtonClick"
        />
    <RadioButton
        android:id="@+id/marathon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/rad_option2"
        android:onClick="onRadioButtonClick"
         />
    <RadioButton
        android:id="@+id/neverending"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/rad_option3"
        android:onClick="onRadioButtonClick"
         />
</RadioGroup>

Then in your code:

public void onRadioButtonClick(View v) {
    RadioButton button = (RadioButton) v;
    // DO YOUR THING HERE DEPENDING ON WHICH RADIOBUTTON IS PICKED
}

In this case, you won't have to deal with disabling other options. The user will have only one option to pick by default.

Answer 2

@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {

    int id = buttonView.getId();

    if(isChecked){
       switch(id){
          case R.id.sprint:
          //add to database
          ...
       }
    }
    else{
      switch(id){
          case R.id.sprint:
          //remove from database
          ...
       }
   }
}

This should allow you to with ID's. Hope it works.

Answer 3

This is the way you are notified about checked changes:

CheckBox check = findViewById(R.id.sprint_checkbox);
check.setOnCheckedChangeListener(new OnCheckedChangeListener() {

        @Override
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
            //do stuff

        }
    });

You can also let your activity implements the OnCheckedChangeListener interface and then:

CheckBox check1 = findViewById(R.id.sprint_checkbox);
CheckBox check2 = findViewById(R.id.marathon_checkbox); 
CheckBox check3 = findViewById(R.id.never_ending_checkbox);

check1.setOnCheckedChangeListener(this);
check2.setOnCheckedChangeListener(this);
check3.setOnCheckedChangeListener(this);

Overriding the interface method:

@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    switch(buttonView.getId()){
               case R.id.sprint_checkbox:
                 //do stuff
               break;
               case R.id.marathon_checkbox:
                 //do stuff
               break;
               case R.id.never_ending_checkbox:
                //do stuff
               break;

            }

}