安卓入门.单选按钮RadioButton和·RadioGroup

单选按钮RadioButton
单选分组RadioGroup

每个RadioGroup，就是一个分组，一个分组里，只有一个单选按钮RadioButton


1.XML文科
<RadioGroup/> <RadioButton/>
<RadioButton/>是<RadioGroup/>的子标签

<RadioGroup 
	    android:id="@+id/radioGroup"
	    android:layout_width="wrap_content"
	    android:layout_height="wrap_content"
	    >
	    <RadioButton 
	        android:id="@+id/nv"
	        android:layout_width="wrap_content"
	        android:layout_height="wrap_content"
	        android:text="女"
	        />
	    <RadioButton 
	        android:text="男"
	        android:id="@+id/nan"
	        android:layout_width="wrap_content"
	        android:layout_height="wrap_content"
	        />
	</RadioGroup> 

2.代码
FindViewById找到控件


3.监听器
OnClickListener，OnCheckedChangeListener





private RadioGroup radioGroup;
	private RadioButton buttonNv;
	private RadioButton buttonNan;

	// 别import错，要导radioButton这个包,实现监听接口
	class RadioGroupListener implements OnCheckedChangeListener {
		@Override
		public void onCheckedChanged(RadioGroup group, int checkedId) {
			if (buttonNan.getId() == checkedId) {
				System.out.println("女");
			} else if (buttonNv.getId() == checkedId) {
				System.out.println("男");
			}
		}
	}

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

		radioGroup = (RadioGroup) findViewById(R.id.radioGroup);
		buttonNan = (RadioButton) findViewById(R.id.nan);//2.FindViewById找到控件
		buttonNv = (RadioButton) findViewById(R.id.nv);

		RadioGroupListener listener = new RadioGroupListener();
		radioGroup.setOnCheckedChangeListener(listener);3.监听器