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：

reslayoutactivity_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);
    }
}