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:

Xml代码  

1. <manifest xmlns:android="http://schemas.android.com/apk/res/android"  
2.       package="com.androidres.ConfigChangedTesting"  
3.       android:versionCode="1"  
4.       android:versionName="1.0.0">  
5.     <application android:icon="@drawable/icon" android:label="@string/app_name">  
6.         <activity android:name=".ConfigChangedTesting"  
7.                   android:label="@string/app_name"  
8.                   android:configChanges="keyboardHidden|orientation">  
9.             <intent-filter>  
10.                 <action android:name="android.intent.action.MAIN" />  
11.                 <category android:name="android.intent.category.LAUNCHER" />  
12.             </intent-filter>  
13.         </activity>  
14.     </application>  
15. </manifest>  

<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:

Xml代码  

1. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"  
2.     android:orientation="vertical"  
3.     android:layout_width="fill_parent"  
4.     android:layout_height="fill_parent"  
5.     >  
6. <Button  
7.         android:id="@+id/pick"  
8.     android:layout_width="fill_parent"  
9.     android:layout_height="wrap_content"  
10.     android:text="Pick"  
11.     />  
12. <Button  
13.         android:id="@+id/view"  
14.     android:layout_width="fill_parent"  
15.     android:layout_height="wrap_content"  
16.     android:text="View"  
17.     />  
18. </LinearLayout>  

<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。


项目的Java源代码：

Java代码  

1. import android.app.Activity;   
2. import android.content.Intent;   
3. import android.content.res.Configuration;   
4. import android.net.Uri;   
5. import android.os.Bundle;   
6. import android.provider.Contacts.People;   
7. import android.view.View;   
8. import android.widget.Button;   
9.   
10.   
11. public class ConfigChangedTesting extends Activity {   
12.     /** Called when the activity is first created. */  
13.     static final int PICK_REQUEST = 1337;   
14.     Button viewButton=null;   
15.     Uri contact = null;   
16.     @Override  
17.     public void onCreate(Bundle savedInstanceState) {   
18.         super.onCreate(savedInstanceState);   
19.         //setContentView(R.layout.main);   
20.   
21.   
22.         setupViews();   
23.     }   
24.   
25.   
26.     public void onConfigurationChanged(Configuration newConfig) {   
27.                  super.onConfigurationChanged(newConfig);     
28.   
29.   
30.                  setupViews();   
31.     }     
32.   
33.   
34.     /* (non-Javadoc)  
35.      * @see android.app.Activity#onActivityResult(int, int, android.content.Intent)  
36.      */  
37.     @Override  
38.     protected void onActivityResult(int requestCode, int resultCode, Intent data) {   
39.         // TODO Auto-generated method stub   
40.         //super.onActivityResult(requestCode, resultCode, data);   
41.   
42.   
43.         if(requestCode == PICK_REQUEST){   
44.   
45.   
46.             if(resultCode==RESULT_OK){   
47.   
48.   
49.                 contact = data.getData();   
50.                 viewButton.setEnabled(true);   
51.             }   
52.   
53.   
54.         }   
55.   
56.   
57.     }   
58.   
59.   
60.     private void setupViews(){   
61.   
62.   
63.         setContentView(R.layout.main);   
64.   
65.   
66.         Button pickBtn = (Button)findViewById(R.id.pick);   
67.   
68.   
69.         pickBtn.setOnClickListener(new View.OnClickListener(){   
70.   
71.   
72.             public void onClick(View v) {   
73.                 // TODO Auto-generated method stub   
74.   
75.   
76.                 Intent i=new Intent(Intent.ACTION_PICK,People.CONTENT_URI);   
77.                 startActivityForResult(i,PICK_REQUEST);   
78.             }   
79.         });   
80.   
81.   
82.         viewButton =(Button)findViewById(R.id.view);     
83.   
84.   
85.         viewButton.setOnClickListener(new View.OnClickListener() {   
86.                     public void onClick(View view) {   
87.                         startActivity(new Intent(Intent.ACTION_VIEW, contact));   
88.                     }   
89.         });     
90.   
91.   
92.         viewButton.setEnabled(contact!=null);   
93.     }   
94. }  

import android.app.Activity;
import android.content.Intent;
import android.content.res.Configuration;
import android.net.Uri;
import android.os.Bundle;
import android.provider.Contacts.People;
import android.view.View;
import android.widget.Button;


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


        setupViews();
    }


    public void onConfigurationChanged(Configuration newConfig) {
                 super.onConfigurationChanged(newConfig);  


                 setupViews();
    }  


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


        if(requestCode == PICK_REQUEST){


            if(resultCode==RESULT_OK){


                contact = data.getData();
                viewButton.setEnabled(true);
            }


        }


    }


    private void setupViews(){


        setContentView(R.layout.main);


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


        pickBtn.setOnClickListener(new View.OnClickListener(){


            public void onClick(View v) {
                // TODO Auto-generated method stub


                Intent i=new Intent(Intent.ACTION_PICK,People.CONTENT_URI);
                startActivityForResult(i,PICK_REQUEST);
            }
        });


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


        viewButton.setOnClickListener(new View.OnClickListener() {
                    public void onClick(View view) {
                        startActivity(new Intent(Intent.ACTION_VIEW, contact));
                    }
        });  


        viewButton.setEnabled(contact!=null);
    }
}

文章来源
翻译：
http://hiapk.com/thread-6199-1-1.html
原文：
http://www.androidguys.com/2008/11/11/rotational-forces-part-three/