How to set a radio button in Android

Question

I have an app that uses radio buttons. The default for this button is set in the main.xml file, ie:

android:id="@+id/rb_sat1E"
android:checked="true"

In the Java file I have:

final RadioButton radio1 = (RadioButton)findViewById(R.id.rb_sat1E);

I have also created a 'Reset' button in the main Java file and can use the following code to reset TextView information ie.

pos1_deg.setText("0.0");

But how do I reset a radio button? I would have thought it to be something like

radio1.setBoolean("TRUE");

But that does not work at all.

Any help greatly appreciated. Thanks.

Caracole

Answer 1

For radioButton use

radio1.setChecked(true);

It does not make sense to have just one RadioButton. If you have more of them you need to uncheck others through

radio2.setChecked(false); ...

If your setting is just on/off use CheckBox.

Smelly

For other readers who may find themselves in my position: setChecked (true), is COMPLETELY DIFFERENT from setSelected (true). Ack. – Beagle

This doesn't work if radio buttons placed in radio group so use answer given by gulchrider – Shrine

Answer 2

If you want to do it in code, you can call the check member of RadioGroup:

radioGroup.check(R.id.radioButtonId);

This will check the button you specify and uncheck the others.

Clump

Thanks :) This is the better answer for me; exactly what I was looking for. – Coenocyte

radioGroup.check(radioGroup.getChildAt(0).getId()); - to check first item on list – Tsosie

I agree. Please do that. – Smelly

Answer 3

Or you can do it in the XML file :

In the RadioGroup using : android:checkedButton="id_button_to_check"

or in the RadioButton : android:checked="true"

Poignant

When I check radiobutton in xml, I cant uncheck it later. It's like that radiobutton is removed from the group – Gallardo

sorry that I'm late, but this is the intended behaviour for radiobuttons. When you select it, you can't unselect it EXCEPT by selecting another radio button in the radiogroup – Carom

we can clear the selection by calling check(-1) or clearCheck(). – Shiite

Answer 4

Just to clarify this: if we have a RadioGroup with several RadioButtons and need to activate one by index, implies that:

radioGroup.check(R.id.radioButtonId)

and

radioGroup.getChildAt(index)`

We can to do:

radioGroup.check(radioGroup.getChildAt(index).getId());

Reimport

Answer 5

if you have done the design in XML and want to show one of the checkbox in the group as checked when loading the page below solutions can help you

    <RadioGroup
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/txtLastNameSignUp"
        android:layout_margin="20dp"
        android:orientation="horizontal"
        android:id="@+id/radioGroup">
<RadioButton
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:checked="true"
    android:id="@+id/Male"
    android:text="Male"/>
        <RadioButton
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/Female"
            android:text="Female"/>
        </RadioGroup>

Litt

Answer 6

Many times if your radio buttons belong to the same radioGroup then

radioButton.setChecked(true)

will not select the radio button properly. So to solve this problem try using your radioGroup.

radioGroup.check(R.id.radioButtonId)

Crop

Answer 7

Use this code

    ((RadioButton)findViewById(R.id.radio3)).setChecked(true);

mistake -> don't forget to give () for whole before setChecked() -> If u forget to do that setChecked() is not available for this radio button

Epicureanism

Answer 8

I have multiple RadioButtons without Group and setChecked(true) works, but setChecked(false) don't works. But this code works:

RadioButton switcher = (RadioButton) view.findViewById(R.id.active);
                        switcher.setOnClickListener(new RadioButton.OnClickListener(){
                            @Override
                            public void onClick(View v) {
                                if(((RadioButton)v).isSelected()){
                                    ((RadioButton)v).setChecked(false);
                                    ((RadioButton)v).setSelected(false);
                                } else {
                                    ((RadioButton)v).setChecked(true);
                                    ((RadioButton)v).setSelected(true);
                                }
                            }

                        });

Attrahent

Answer 9

btnDisplay.setOnClickListener(new OnClickListener() {

    @Override
    public void onClick(View v) {

            // get selected radio button from radioGroup
        int selectedId = radioSexGroup.getCheckedRadioButtonId();

        // find the radiobutton by returned id
            radioSexButton = (RadioButton) findViewById(selectedId);

        Toast.makeText(MyAndroidAppActivity.this,
            radioSexButton.getText(), Toast.LENGTH_SHORT).show();

    }

});

Alesandrini

Can you please explain why OP should use your code? – Coerce