How can I add radio buttons to a radio group I've made programmatically?

Question

I am completely new to Android

i tried whatever I thought may work but everytime I get error. What's wrong here?

main_activity.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="16dp"
    tools:context=".Main"
    android:orientation="vertical"
    android:id="@+id/mainLayout">
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <RadioButton
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="New RadioButton"
            android:id="@+id/radioButton1" />
        <RadioButton
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="New RadioButton"
            android:id="@+id/radioButton2" />
        <RadioButton
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="New RadioButton"
            android:id="@+id/radioButton3" />
    </LinearLayout>
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <RadioButton
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="New RadioButton"
            android:id="@+id/radioButton4" />
        <RadioButton
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="New RadioButton"
            android:id="@+id/radioButton5" />

        <RadioButton
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="New RadioButton"
            android:id="@+id/radioButton6" />
    </LinearLayout>
</LinearLayout>

Main.java

public class Main extends AppCompatActivity {

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

        RadioButton rb1 = (RadioButton) findViewById(R.id.radioButton1);
        RadioButton rb2 = (RadioButton) findViewById(R.id.radioButton2);
        RadioButton rb3 = (RadioButton) findViewById(R.id.radioButton3);
        RadioButton rb4 = (RadioButton) findViewById(R.id.radioButton4);
        RadioButton rb5 = (RadioButton) findViewById(R.id.radioButton5);
        RadioButton rb6 = (RadioButton) findViewById(R.id.radioButton6);

        RadioGroup rg = new RadioGroup(this);
        rg.addView(rb1);
        rg.addView(rb2);
        rg.addView(rb3);
        rg.addView(rb4);
        rg.addView(rb5);
        rg.addView(rb6);

    }

}

in fact I am trying to make a radio group with 3 columns and 2 rows but as I tried it doesn't work when I do it like this:

main_activity.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="16dp"
    tools:context=".Main"
    android:orientation="vertical"
    android:id="@+id/mainLayout">
  <RadioGroup
      android:layout_width="fill_parent"
      android:layout_height="wrap_content">
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <RadioButton
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="New RadioButton"
            android:id="@+id/radioButton1" />
        <RadioButton
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="New RadioButton"
            android:id="@+id/radioButton2" />
        <RadioButton
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="New RadioButton"
            android:id="@+id/radioButton3" />
    </LinearLayout>
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <RadioButton
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="New RadioButton"
            android:id="@+id/radioButton4" />
        <RadioButton
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="New RadioButton"
            android:id="@+id/radioButton5" />
        <RadioButton
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="New RadioButton"
            android:id="@+id/radioButton6" />
    </LinearLayout>
 </RadioGroup>
</LinearLayout>

the last solution I got is to make a radio group in Main.java programmatically but it makes an error on rg.addView() method

`RadioGroup rg = new RadioGroup(this);`. No you should define an empty RadioGroup in the xml file. Then at runtime create RadioButtons and add them to the RadioGroup. — greenapps, Aug 12 '15 at 14:15
Here you go - http://stackoverflow.com/questions/6646442/creating-radiobuttons-programmatically — Andrew Fielden, Aug 12 '15 at 14:28

score 0 · Answer 1 · answered Aug 12 '15 at 14:15

0

Try to create the RadioGroup in the xml and get a reference to it in java then use the reference to do your stuff. Or you could add the RadioGroup to your layout if you wanna keep the java RadioGroup.

answered Aug 12 '15 at 14:15

LukaxH

71
9

1

no it doesn't work because you cannot add RadioButtons to it. you face error because you are trying to add views in a parent within they are there already! (sorry about my broken english) – ShahinSorkh Aug 17 '15 at 14:24

score 0 · Accepted Answer · edited Apr 26 '16 at 09:45

I've found my solution!

I created a new RadioGroup class which I can put my RadioButtons in a group without breaking my main.xml layout!

here is the class I just created:

import android.view.View;
import android.widget.RadioButton;

/**
 * <p>
 *     CREATED:<br />&nbsp;&nbsp;&nbsp;&nbsp;
 *          15 Aug 2015
 * </p>
 * <p>
 *     This class is created to make a RadioGroup
 *     with no limitation of designing and layouting.
 *  <br />
 *  <strong>
 *      The first method you have to call is
 *      <em>createRadioGroup ()</em> to
 *      initialize your RadioGroup.
 *  </strong>
 *  <br />
 *     Feel free to browse in the class
 *     and making change in it as you need.
 * </p>
 * @author ShahinSorkh
 * @version 1
 */
public class RadioGroup2 {

// Global variables
private RadioButton rb [];
private int firstCheckedItemId;
public static int countRadioButtons;

/**
 * <p>
 *     will initialize your RadioGroup
 * </p>
 * <p>
 *     <strong>an example:</strong>
 *     <p>
 *         RadioGroup2 rg = new RadioGroup2;<br />
 *         RadioButton rb [] = new RadioButton[3];<br />
 *         rb[0] = (RadioButton)findViewById(R.id.radio1);<br />
 *         rb[1] = (RadioButton)findViewById(R.id.radio2);<br />
 *         rb[2] = (RadioButton)findViewById(R.id.radio3);<br />
 *         rg.createRadioGroup(rb);
 *     </p>
 * </p>
 * @param radioButtons an Array of RadioButtons
 */
public void createRadioGroup(RadioButton [] radioButtons){
    rb = radioButtons;
    firstCheckedItemId = getCheckedItemId();
    countRadioButtons = rb.length;
    onCheck();
}

private void onCheck(){
    for (RadioButton aRb : rb) {
        aRb.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View radio) {
                final RadioButton myRb = (RadioButton) radio;
                for (RadioButton aRb : rb) {
                    if (aRb.getId() == myRb.getId()) {
                        aRb.setChecked(true);
                    } else aRb.setChecked(false);
                }
            }
        });
    }
}

/**
 * will count RadioButtons in your RadioGroup
 * @return the count of RadioButtons in RadioGroup
 */
public int getRadioButtonsCount(){
    return countRadioButtons;
}

/**
 * <p>
 *     will return the checked item <strong>ID</strong>
 *     <em>you can use in findViewById() for example</em>
 * </p>
 * <p>
 *     will return <em>-1</em> if no RadioButton has checked<br />
 *     better to check if any button has checked
 * </p>
 * @return int checkedRadioButtonId
 */
public int getCheckedItemId (){
    int id = -1;
    for (RadioButton aRb : rb) {
        if(aRb.isChecked())
            id = aRb.getId();
    }
    return id;
}

/**
 * <p>
 *     will return the checked <strong>RadioButton</strong>
 * </p>
 * <p>
 *     will return <em>null</em> if no RadioButton has checked<br />
 *     better to check if any button has checked
 * </p>
 * @return checked RadioButton directly
 */
public RadioButton getCheckedItem (){
    RadioButton RB = null;
    for (RadioButton aRb : rb) {
        if(aRb.isChecked())
            RB = aRb;
    }
    return RB;
}

/**
 * will reset all RadioButtons checked state
 * to default, all RadioButtons will unCheck
 * and the firstChecked RadioButton will check
 * at end
 */
public void resetButtons(){
    RadioButton iRb = getCheckedItem();
    if(iRb != null)
        iRb.setChecked(false);
    if(firstCheckedItemId != -1)
        getChildById(firstCheckedItemId).setChecked(true);
}

private RadioButton getChildById(int id){
    RadioButton iRb = null;
    for (RadioButton aRb : rb ) {
        if(aRb.getId() == id) {
            iRb = aRb;
            break;
        }
    }
    return iRb;
}

/**
 * <p>
 *     will return <strong>RadioButton</strong> at given index in the Array
 * </p>
 * @param position index of RadioButton in Array
 * @return RadioButton[i]
 */
public RadioButton getChildAt (int position){
    return rb[position];
}
}

and create my RadioGroup like this:

RadioGroup2 rg = new RadioGroup2 ();
RadioButton [] rb = new RadioButton [3]();

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

rb[0] = (RadioButton) findViewById(R.id.rb1);
rb[1] = (RadioButton) findViewById(R.id.rb2);
rb[2] = (RadioButton) findViewById(R.id.rb3);

rg.createRadioGroup(rb);
...
}

I don't know if more methods or behaviors is required or no, this class is acting as I needed.

thank everybody who took their time on this

How can I add radio buttons to a radio group I've made programmatically?

2 Answers2

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