Error: OnCheckedChangeListener cannot be resolved to a type

Question

I have red lines under setOnCheckedChangeListener and OnCheckedChangeListener. The error message is telling me: Multiple Markers at this line - OnCheckedChangedListener cannot be resolved to a type - the method setOnCheckedChangedListener(RadioGroup.OnCheckedChangeListener) in the type RadioGroup is not applicable for the arguments (new OnCheckedChangeListener(){})

package com.lifematters;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.View;
import android.widget.Button;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;

public class Test1 extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.test1);

    //define Navigation Image Buttons
    final Button nextBtn = (Button) findViewById(R.id.btnNext);



    RadioGroup radioGroup = (RadioGroup) findViewById(R.id.radioAnswers1);
    radioGroup.setOnCheckedChangeListener(new OnCheckedChangeListener()
    {
        public void onCheckedChanged (RadioGroup group, int checkedId){

        final RadioButton radioButton1 = (RadioButton) findViewById(R.id.radioA1);
        final RadioButton radioButton2 = (RadioButton) findViewById(R.id.radioA2);
        final RadioButton radioButton3 = (RadioButton) findViewById(R.id.radioA3);
        final RadioButton radioButton4 = (RadioButton) findViewById(R.id.radioA4);

        if (radioButton1.isChecked()) {
            DisplayToast("No, not at all");

        } else if (radioButton2.isChecked()) {
            DisplayToast("On some days");

        }else if (radioButton3.isChecked()) {
            DisplayToast("On more than half the days");

        }else {
            DisplayToast("Nearly everyday");
        }
    }

  });


  }

} 

Answer 1

Two possibilities:

• Change to RadioGroup.OnCheckedChangeListener

• Add this to the start of your class:

  import android.widget.RadioGroup.OnCheckedChangeListener;
  

As for DisplayToast, add the following:

public void displayToast(String text){
    Toast.makeText(this, text, Toast.Toast.LENGTH_SHORT).show();
}

And change DisplayToast to displayToast in your code. Method names should start with a lower-case letter by convention. Only class names should start with an upper-case letter.

Answer 2

You need to import

import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;

Answer 3

Import these Two class/interface.

import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;

This code may help for OnChacked Changed

• //buttonView.getId() is used to get the ids of Button

• //boolean isChecked is used that button is Checked or not

  public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
  
  
  if (isChecked) {
  
      switch (buttonView.getId()) {
  
      case R.id.radioA1:
            DisplayToast("No, not at all");
          radioA2.setChecked(false);
          break;
  
      case R.id.radioA2:
          DisplayToast("On some days")
          radioA1.setChecked(false);
          break;
  
                  .....
                  .....
  
  
      default:
          break;
      }
  
  }
  

  }

Answer 4

I had the same problem and solved it this way:

Just change

.setOnCheckedChangeListener(new OnCheckedChangeListener(){...

to

.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener(){...

and it will be working!