How to check how many checkboxes are checked and display in textview on button clicked

Question

I have 3 check boxes and textviews, I want to keep track how many checkboxes are checked and which and display final result in textView on button clicked. How can I do that?

Answer 1

Let say you have a parent LinearLayout and and it has three checkboxes.

Create reference of LinearLayout.

LineaLayout linearLayout = (LinearLayout) findVIewById(R.id.lv);

Then, CheckBox states you have to iterate through ChildViews of linearlayout.

Something like,

for (int i = 0; i < linearLayout.getChildCount(); i++) {
    View v = linearLayout.getChildAt(i);
    if (v instanceof CheckBox) {
      if (((CheckBox) v).isChecked())
      // Check Checkbox
      else
      // Unchecked Checkbox
    } 
}

Answer 2

To determine if a CheckBox is checked, you can call myCheckbox.isChecked() . To set the value of a TextView , you can call myTextView.setText() . And to do something when a Button is pressed, you can add a View.OnClickListener using myButton.setOnClickListener() .

Together, that means you can create a program like this:

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final CheckBox checkBox1 = (CheckBox) findViewById(R.id.checkbox1);
        final CheckBox checkBox2 = (CheckBox) findViewById(R.id.checkbox2);
        final CheckBox checkBox3 = (CheckBox) findViewById(R.id.checkbox3);
        final TextView textView = (TextView) findViewById(R.id.text);

        Button button = (Button) findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                int count = 0;

                if (checkBox1.isChecked()) {
                    ++count;
                }

                if (checkBox2.isChecked()) {
                    ++count;
                }

                if (checkBox3.isChecked()) {
                    ++count;
                }

                textView.setText("How many checked? " + count);
            }
        });
    }
}

Answer 3

The best approach is to use listview :

Create a ListView first and create a custom adapter having the the checkbox in each rows.

In Adapter have a Set<Integer> indexes = new HashSet<Integer>()

In the getView() method : getView (int position, View convertView, ViewGroup parent)

Assign click listener for the checkbox :

checkbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
       @Override
       public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) 
       {
          if(isChecked){
             indexes.add(position); 
          }else{
             indexes.remove(position);
          }

       }
   }
); 

Finally just access the set and you will get, length of set, ie the number of checkboxes selected and the values represent the position of the selected checkbox.