Android：CheckBox控件

1）ChexkBox继承自CompoundButton组件；

2）isChecked()--确定是否选中；setChecked(bool checked)--设置选中或取消选中；

3）监听事件：CompoundButton.OnCheckedChangeListener

使用checkbox，并实现监听测试：

1）效果：

2）源代码：

res\layout\activity_main.xml

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >

    <CheckBox
        android:id="@+id/cbJava"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_marginLeft="27dp"
        android:text="Java Runtime 9.0" />

    <TextView
        android:id="@+id/tvCheckedValue"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/cbJava"
        android:layout_below="@+id/cbPython"
        android:layout_marginLeft="14dp"
        android:layout_marginTop="54dp"
        android:text="" />

    <CheckBox
        android:id="@+id/cbPython"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/cbJava"
        android:layout_below="@+id/cbJava"
        android:layout_marginTop="22dp"
        android:text="Python runtime2.7" />

</RelativeLayout>

MainActivity.java

 package com.example.helloword;

 import java.text.BreakIterator;

 import android.R.bool;
 import android.R.string;
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.content.DialogInterface;
 import android.content.DialogInterface.OnClickListener;
 import android.os.Bundle;
 import android.renderscript.Script.KernelID;
 import android.test.IsolatedContext;
 import android.util.Log;
 import android.view.KeyEvent;
 import android.view.Menu;
 import android.view.View;
 import android.widget.Button;
 import android.widget.CheckBox;
 import android.widget.CompoundButton;
 import android.widget.EditText;
 import android.widget.ImageView;
 import android.widget.RadioButton;
 import android.widget.RadioGroup;
 import android.widget.TextView;

 public class MainActivity extends Activity {
     private CheckBox cbJava, cbPython;
     private TextView tvCheckedValue;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         this.cbJava = (CheckBox) this.findViewById(R.id.cbJava);
         this.cbPython = (CheckBox) this.findViewById(R.id.cbPython);
         this.tvCheckedValue = (TextView) this.findViewById(R.id.tvCheckedValue);

         CheckBoxOnCheckedChangeListener listener = new CheckBoxOnCheckedChangeListener();

         this.cbJava.setOnCheckedChangeListener(listener);
         this.cbPython.setOnCheckedChangeListener(listener);

     }

     private StringBuffer stringBuffer;

     private class CheckBoxOnCheckedChangeListener implements
             CompoundButton.OnCheckedChangeListener {
         private String checkJava = cbJava.getText().toString() + " ";
         private String checkPython = cbPython.getText().toString() + " ";
         private StringBuffer stringBuffer = new StringBuffer();

         @Override
         public void onCheckedChanged(CompoundButton compoundButton,
                 boolean ischecked) {
             switch (compoundButton.getId()) {
             case R.id.cbJava:
                 Log.i("info", "operator " + cbJava.getText());
                 break;
             case R.id.cbPython:
                 Log.i("info", "operator " + cbPython.getText());
                 break;
             default:
                 break;
             }

             if (compoundButton == cbJava) {
                 changeValue(ischecked, checkJava);
             } else if (compoundButton == cbPython) {
                 changeValue(ischecked, checkPython);
             }

             tvCheckedValue.setText(stringBuffer.toString());
         }

         private void changeValue(boolean ischecked, String checkValue) {
             int start = stringBuffer.indexOf(checkValue);
             int end = start + checkValue.length();
             if (ischecked) {
                 if (start == -1) {
                     stringBuffer.append(checkValue);
                 }
             } else {
                 if (start != -1) {
                     stringBuffer.delete(start, end);
                 }
             }
         }
     }

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

     @Override
     public boolean onKeyUp(int keyCode, KeyEvent event) {
         // 当点击回退时，弹出该窗口（也就相当于关闭操作）
         if (keyCode == KeyEvent.KEYCODE_BACK) {
             new AlertDialog.Builder(this).setTitle("是否退出？")
                     .setPositiveButton("确定", new OnClickListener() {
                         @Override
                         public void onClick(DialogInterface arg0, int arg1) {
                             finish();
                         }
                     }).setNegativeButton("取消", null).show();
             return true;
         }
         return super.onKeyUp(keyCode, event);
     }
 }