常用控件（1）—RadioGroup、CheckBox、Toast

MainActivity:

package com.example.kj;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.Toast;

public class MainActivity extends Activity {

    private RadioGroup g1 = null;
    private RadioButton B1 = null;
    private CheckBox cb = null;

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

        g1 = (RadioGroup) findViewById(R.id.radiogroup);
        B1 = (RadioButton) findViewById(R.id.B1);
        cb = (CheckBox) findViewById(R.id.CB);
        
        //绑定一个listenner在一个CheckBox上
        cb.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
                // TODO Auto-generated method stub
                if(isChecked==true){
                    //用Toast显示（小提示显示）
                    Toast.makeText(MainActivity.this, "CB!", Toast.LENGTH_SHORT).show();
                    
                }
                
            }
        });

        g1.setOnCheckedChangeListener(new RadioGroup.OnCheckedChangeListener() {

            public void onCheckedChanged(RadioGroup group, int checkedId) {
                // TODO Auto-generated method stub
                if (B1.getId() == checkedId) {
                    System.out.println("B1 Has Been Checked!");
                    Toast.makeText(MainActivity.this, "B1!", Toast.LENGTH_SHORT)
                            .show();
                }

            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

}

Main.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:orientation="vertical"
    tools:context=".MainActivity" >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

    <RadioGroup
        android:id="@+id/radiogroup"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical" >

        <RadioButton
            android:id="@+id/B1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/a" />

        <RadioButton
            android:id="@+id/B2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/b" />

        <RadioButton
            android:id="@+id/B3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/c" />

        <RadioButton
            android:id="@+id/B4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/d" />
    </RadioGroup>
    
    <CheckBox 
            android:id="@+id/CB"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/CB"
        />

</LinearLayout>