Android进阶之RadioButton选中值的获取

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    tools:context="wf.com.radiobuttondemo.MainActivity">    <TextView        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="性别是："        />    <RadioGroup        android:id="@+id/radioGroup"        android:layout_width="match_parent"        android:layout_height="wrap_content"        >        <RadioButton            android:id="@+id/radioMan"            android:layout_height="wrap_content"            android:layout_width="match_parent"            android:text="男"            />        <RadioButton            android:id="@+id/radioWonan"            android:layout_height="wrap_content"            android:layout_width="match_parent"            android:text="女"            />    </RadioGroup>    <TextView        android:id="@+id/txt_sex"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="性别是："        /></LinearLayout>2、MainActivity
public class MainActivity extends Activity {    @BindView(R.id.radioMan)    RadioButton radioMan;    @BindView(R.id.radioWonan)    RadioButton radioWonan;    @BindView(R.id.radioGroup)    RadioGroup radioGroup;    @BindView(R.id.txt_sex)    TextView txtSex;    @Override    PRotected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        ButterKnife.bind(this);
//通过RadioGroup的setOnCheckedChangeListener（）来监听选中哪一个单选按钮        radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {            @Override            public void onCheckedChanged(RadioGroup group, int checkedId) {                selectRadioButton();            }        });    }    private void selectRadioButton() {
//通过radioGroup.getCheckedRadioButtonId()来得到选中的RadioButton的ID，从而得到RadioButton进而获取选中值        RadioButton rb = (RadioButton)MainActivity.this.findViewById(radioGroup.getCheckedRadioButtonId());        txtSex.setText(rb.getText());    }}  第二种方式：    需要利用一下三个方法    （1）radiogroup.getChildCount()   获取radiogroup中子组件（radioButton）的数目    （2）radiogroup.getChildAt()         根据索引获取当前索引对应的radioButton    （3）radiobutton.isChecked()        判断当前组件是否被选中    整体思路是，对radiogroup中组件进行循环，依次判断isChecked（），从而找到选中的组件1、布局文件
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:id="@+id/activity_main"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    tools:context="wf.com.radiobuttondemo.MainActivity">    <TextView        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="性别是："        />    <RadioGroup        android:id="@+id/radioGroup"        android:layout_width="match_parent"        android:layout_height="wrap_content"        >        <RadioButton            android:id="@+id/radioMan"            android:layout_height="wrap_content"            android:layout_width="match_parent"            android:text="男"            />        <RadioButton            android:id="@+id/radioWonan"            android:layout_height="wrap_content"            android:layout_width="match_parent"            android:text="女"            />    </RadioGroup>    <TextView        android:id="@+id/txt_sex"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:text="性别是："        />    <Button        android:id="@+id/btn_submit"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="提交"        /></LinearLayout>2、MainActivity
public class MainActivity extends Activity {    @BindView(R.id.radioMan)    RadioButton radioMan;    @BindView(R.id.radioWonan)    RadioButton radioWonan;    @BindView(R.id.radioGroup)    RadioGroup radioGroup;    @BindView(R.id.txt_sex)    TextView txtSex;    @BindView(R.id.btn_submit)    Button btnSubmit;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        ButterKnife.bind(this);    }    @OnClick(R.id.btn_submit)    public void onClick() {        for(int i = 0 ;i < radioGroup.getChildCount();i++){            RadioButton rb = (RadioButton)radioGroup.getChildAt(i);            if(rb.isChecked()){                txtSex.setText(rb.getText());                break;            }        }    }}