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

  1 package com.example.helloword;
  2
  3 import java.text.BreakIterator;
  4
  5 import android.R.bool;
  6 import android.R.string;
  7 import android.app.Activity;
  8 import android.app.AlertDialog;
  9 import android.content.DialogInterface;
 10 import android.content.DialogInterface.OnClickListener;
 11 import android.os.Bundle;
 12 import android.renderscript.Script.KernelID;
 13 import android.test.IsolatedContext;
 14 import android.util.Log;
 15 import android.view.KeyEvent;
 16 import android.view.Menu;
 17 import android.view.View;
 18 import android.widget.Button;
 19 import android.widget.CheckBox;
 20 import android.widget.CompoundButton;
 21 import android.widget.EditText;
 22 import android.widget.ImageView;
 23 import android.widget.RadioButton;
 24 import android.widget.RadioGroup;
 25 import android.widget.TextView;
 26
 27 public class MainActivity extends Activity {
 28     private CheckBox cbJava, cbPython;
 29     private TextView tvCheckedValue;
 30
 31     @Override
 32     protected void onCreate(Bundle savedInstanceState) {
 33         super.onCreate(savedInstanceState);
 34         setContentView(R.layout.activity_main);
 35         this.cbJava = (CheckBox) this.findViewById(R.id.cbJava);
 36         this.cbPython = (CheckBox) this.findViewById(R.id.cbPython);
 37         this.tvCheckedValue = (TextView) this.findViewById(R.id.tvCheckedValue);
 38
 39         CheckBoxOnCheckedChangeListener listener = new CheckBoxOnCheckedChangeListener();
 40
 41         this.cbJava.setOnCheckedChangeListener(listener);
 42         this.cbPython.setOnCheckedChangeListener(listener);
 43
 44     }
 45
 46     private StringBuffer stringBuffer;
 47
 48     private class CheckBoxOnCheckedChangeListener implements
 49             CompoundButton.OnCheckedChangeListener {
 50         private String checkJava = cbJava.getText().toString() + " ";
 51         private String checkPython = cbPython.getText().toString() + " ";
 52         private StringBuffer stringBuffer = new StringBuffer();
 53
 54         @Override
 55         public void onCheckedChanged(CompoundButton compoundButton,
 56                 boolean ischecked) {
 57             switch (compoundButton.getId()) {
 58             case R.id.cbJava:
 59                 Log.i("info", "operator " + cbJava.getText());
 60                 break;
 61             case R.id.cbPython:
 62                 Log.i("info", "operator " + cbPython.getText());
 63                 break;
 64             default:
 65                 break;
 66             }
 67
 68             if (compoundButton == cbJava) {
 69                 changeValue(ischecked, checkJava);
 70             } else if (compoundButton == cbPython) {
 71                 changeValue(ischecked, checkPython);
 72             }
 73
 74             tvCheckedValue.setText(stringBuffer.toString());
 75         }
 76
 77         private void changeValue(boolean ischecked, String checkValue) {
 78             int start = stringBuffer.indexOf(checkValue);
 79             int end = start + checkValue.length();
 80             if (ischecked) {
 81                 if (start == -1) {
 82                     stringBuffer.append(checkValue);
 83                 }
 84             } else {
 85                 if (start != -1) {
 86                     stringBuffer.delete(start, end);
 87                 }
 88             }
 89         }
 90     }
 91
 92     @Override
 93     public boolean onCreateOptionsMenu(Menu menu) {
 94         // Inflate the menu; this adds items to the action bar if it is present.
 95         getMenuInflater().inflate(R.menu.main, menu);
 96         return true;
 97     }
 98
 99     @Override
100     public boolean onKeyUp(int keyCode, KeyEvent event) {
101         // 当点击回退时，弹出该窗口（也就相当于关闭操作）
102         if (keyCode == KeyEvent.KEYCODE_BACK) {
103             new AlertDialog.Builder(this).setTitle("是否退出？")
104                     .setPositiveButton("确定", new OnClickListener() {
105                         @Override
106                         public void onClick(DialogInterface arg0, int arg1) {
107                             finish();
108                         }
109                     }).setNegativeButton("取消", null).show();
110             return true;
111         }
112         return super.onKeyUp(keyCode, event);
113     }
114 }