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: 

 <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: 

 <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： 

 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/ 

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