Android学习第12课—常用控件（二）

主要内容：
1 RadioGroup和RadioButton的使用方法
 这两个控件代表Android中单选按钮的控件，单选按钮必须要创建一个组
2 CheckBox的使用方法
 CheckBox是多选按钮
3 Toast的基本用法
 Toast控件类似弹出的提示信息

注意：RadioGroup和CheckBox使用的监听器的OnCheckedChangeLiatener不一样—RadioGroup要使用的对象不是CompoundButton的子类，所以不能使用CompoundedButton，所以他只能重新编写一个OnCheckedChangeListener的接口； 而CheckBox是CompoundButton的子类，所以他能直接使用CompoundButton。

布局文件实例：

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" >    <TextView        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:text="@string/hello" />    <RadioGroup         android:id="@+id/radiogroup"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:orientation="vertical"        >        <RadioButton             android:id="@+id/femaleButton"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="@string/female"            />        <RadioButton             android:id="@+id/maleButton"            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="@string/male"            />    </RadioGroup>        <CheckBox         android:id="@+id/swim"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="swim"        />    <CheckBox         android:id="@+id/run"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="run"        />    <CheckBox         android:id="@+id/read"        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="read"        /></LinearLayout>

Activity文件：

package dj.activity;import android.app.Activity;import android.os.Bundle;import android.widget.CheckBox;import android.widget.CompoundButton;import android.widget.RadioButton;import android.widget.RadioGroup;import android.widget.Toast;public class Activity13 extends Activity {    /** Called when the activity is first created. */private RadioGroup radioGroup = null;private RadioButton femaleButton = null;private RadioButton maleButton = null;private CheckBox swimBox = null;private CheckBox runBox = null;private CheckBox readBox = null;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                radioGroup = (RadioGroup)findViewById(R.id.radiogroup);        femaleButton = (RadioButton)findViewById(R.id.femaleButton);        maleButton = (RadioButton)findViewById(R.id.maleButton);        swimBox = (CheckBox)findViewById(R.id.swim);        runBox = (CheckBox)findViewById(R.id.run);        readBox = (CheckBox)findViewById(R.id.read);                radioGroup.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {@Overridepublic void onCheckedChanged(RadioGroup group, int checkedId) {// TODO Auto-generated method stubif(femaleButton.getId() == checkedId){System.out.println("female");Toast.makeText(Activity13.this, "female", Toast.LENGTH_SHORT);}else if(maleButton.getId() == checkedId){System.out.println("male");//Toast.makeText(Activity13.this, "male", Toast.LENGTH_SHORT);}}});                swimBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {@Overridepublic void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {// TODO Auto-generated method stubif(isChecked)System.out.println("swim is checked!");elseSystem.out.println("swim is unchecked!");}});        runBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {@Overridepublic void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {// TODO Auto-generated method stubif(isChecked)System.out.println("run is checked!");elseSystem.out.println("run is unchecked!");}});        readBox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {@Overridepublic void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {// TODO Auto-generated method stubif(isChecked)System.out.println("read is checked!");elseSystem.out.println("read is unchecked!");}});    }}