Activity中ConfigChanges属性的用法

 通过设置这个属性可以使Activity捕捉设备状态变化，以下是可以被识别的内容：  
CONFIG_FONT_SCALE
CONFIG_MCC
CONFIG_MNC
CONFIG_LOCALE
CONFIG_TOUCHSCREEN
CONFIG_KEYBOARD
CONFIG_NAVIGATION
CONFIG_ORIENTATION

设置方法：将下列字段用“|”符号分隔开，例如：“locale|navigation|orientation
”

Value	Description
“mcc“	The IMSI mobile country code (MCC) has changed — that is, a SIM hasbeen detected and updated the MCC.移动国家号码，由三位数字组成，每个国家都有自己独立的MCC，可以识别手机用户所属国家。
“mnc“	The IMSI mobile network code (MNC) has changed — that is, a SIM hasbeen detected and updated the MNC.移动网号，在一个国家或者地区中，用于区分手机用户的服务商。
“locale“	The locale has changed — for example, the user has selected a new language that text should be displayed in.用户所在地区发生变化。
“touchscreen“	The touchscreen has changed. (This should never normally happen.)
“keyboard“	The keyboard type has changed — for example, the user has plugged in an external keyboard.键盘模式发生变化，例如：用户接入外部键盘输入。
“keyboardHidden“	The keyboard accessibility has changed — for example, the user has slid the keyboard out to expose it.用户打开手机硬件键盘
“navigation“	The navigation type has changed. (This should never normally happen.)
“orientation“	The screen orientation has changed — that is, the user has rotated the device.设备旋转，横向显示和竖向显示模式切换。
“fontScale“	The font scaling factor has changed — that is, the user has selected a new global font size.全局字体大小缩放发生改变

通过一个例子介绍这个属性的用法： 首先需要修改项目的manifest:

View Code XML

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="com.androidres.ConfigChangedTesting"
      android:versionCode="1"
      android:versionName="1.0.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".ConfigChangedTesting"
                  android:label="@string/app_name"
                  android:configChanges="keyboardHidden|orientation">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

在Activity中添加了 android:configChanges属性，目的是当所指定属性(Configuration Changes)发生改变时，通知程序调用 onConfigurationChanged()函数。 创建一个Layout UI:
?View Code XML

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
<Button
        android:id="@+id/pick"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Pick"
    />
<Button
        android:id="@+id/view"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="View"
    />
</LinearLayout>

这个简单的UI包含两个按钮，其中一个是通过Contact列表选择一个联系人，另外一个是查看当前选择联系人的详细内容。

01.import android.app.Activity;
02.import android.content.Intent;
03.import android.content.res.Configuration;
04.import android.net.Uri;
05.import android.os.Bundle;
06.import android.provider.Contacts.People;
07.import android.view.View;
08.import android.widget.Button;
09.

10.public class ConfigChangedTesting extends Activity {
11.    /** Called when the activity is first created. */
12.    static final int PICK_REQUEST = 1337;
13.    Button viewButton=null;
14.    Uri contact = null;
15.    @Override
16.    public void onCreate(Bundle savedInstanceState) {
17.        super.onCreate(savedInstanceState);
18.        //setContentView(R.layout.main);
19.

20.        setupViews();
21.    }
22.

23.    public void onConfigurationChanged(Configuration newConfig) {
24.                 super.onConfigurationChanged(newConfig);  
25.

26.                 setupViews();
27.    }  
28.

29.    /* (non-Javadoc)
30.     * @see android.app.Activity#onActivityResult(int, int, android.content.Intent)
31.     */
32.    @Override
33.    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
34.        // TODO Auto-generated method stub
35.        //super.onActivityResult(requestCode, resultCode, data);
36.

37.        if(requestCode == PICK_REQUEST){
38.

39.            if(resultCode==RESULT_OK){
40.

41.                contact = data.getData();
42.                viewButton.setEnabled(true);
43.            }
44.

45.        }
46.

47.    }
48.

49.    private void setupViews(){
50.

51.        setContentView(R.layout.main);
52.

53.        Button pickBtn = (Button)findViewById(R.id.pick);
54.

55.        pickBtn.setOnClickListener(new View.OnClickListener(){
56.

57.            public void onClick(View v) {
58.                // TODO Auto-generated method stub
59.

60.                Intent i=new Intent(Intent.ACTION_PICK,People.CONTENT_URI);
61.                startActivityForResult(i,PICK_REQUEST);
62.            }
63.        });
64.

65.        viewButton =(Button)findViewById(R.id.view);  
66.

67.        viewButton.setOnClickListener(new View.OnClickListener() {
68.                    public void onClick(View view) {
69.                        startActivity(new Intent(Intent.ACTION_VIEW, contact));
70.                    }
71.        });  
72.

73.        viewButton.setEnabled(contact!=null);
74.    }
75.}