I have two RadioButtons within a RadioGroup. I also set up a Button, with a setOnClickListener function. When the button is pressed, its supposed to set the float variable gender to a specific value depending on what RadioButton is selected. However, whenever the button is pressed the app crashes.
I've tried setting up a TextView just to see if it would print anything, but the app just crashes when the button is pressed. I looked into the Logcat, and saw that it threw this error: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.CharSequence android.widget.RadioButton.getText()' on a null object reference
package com.example.bacwatch;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.TextView;
import android.widget.Toast;
public class ProfileFragment extends Fragment {
private EditText editWeight;
private Button buttonConfirm;
public float gender;
RadioGroup radioGroup;
RadioButton radioButton;
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_profile, container, false);
radioGroup = v.findViewById(R.id.gender_buttons);
editWeight = v.findViewById(R.id.edit_Weight);
buttonConfirm = v.findViewById(R.id.confirm_button);
editWeight.addTextChangedListener(loginTextWatcher);
// Button will input text.
buttonConfirm.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// Records the gender from the selected radio button.
int radioID = radioGroup.getCheckedRadioButtonId();
radioButton = v.findViewById(radioID);
if (radioButton.getText().equals("Male")) {
gender = (float) .58;
} else {
gender = (float) .49;
}
// Records User's weight (in pounds) and stores it into a variable.
/*float weight = Float.valueOf(editWeight.getText().toString().trim()).floatValue();
// Converts pounds to kilograms.
float kilo_weight = (float) (weight/2.2046);
// Calculates total body water.
float body_water = kilo_weight*gender;*/
// Clears text entries.
editWeight.getText().clear();
}
});
return v;
}
private TextWatcher loginTextWatcher = new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence s, int start, int count, int after) {
}
@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {
String weightInput = editWeight.getText().toString().trim();
buttonConfirm.setEnabled(!weightInput.isEmpty());
}
@Override
public void afterTextChanged(Editable s) {
}
};
}
XML file:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent"
android:background="@android:color/holo_green_light"
android:gravity="center">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Gender:"
android:textSize="30sp"
android:layout_centerHorizontal="true"
android:id="@+id/gender_text"/>
<RadioGroup
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/gender_text"
android:layout_centerHorizontal="true"
android:orientation="horizontal"
android:id="@+id/gender_buttons">
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Male"
android:checked="true"
android:textSize="30sp"
android:id="@+id/male_button"/>
<RadioButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Female"
android:textSize="30sp"
android:id="@+id/female_button"/>
</RadioGroup>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_below="@+id/gender_buttons"
android:id="@+id/weight_box">
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="@+id/weight_input">
<android.support.design.widget.TextInputEditText
android:layout_width="300dp"
android:layout_height="wrap_content"
android:hint="Weight in Pounds"
android:textSize="30sp"
android:inputType="number"
android:id="@+id/edit_Weight"/>
</android.support.design.widget.TextInputLayout>
</LinearLayout>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@+id/weight_box"
android:layout_centerHorizontal="true"
android:textSize="30sp"
android:text="Confirm"
android:enabled="false"
android:id="@+id/confirm_button"/>
</RelativeLayout>
