【亲测】Activity中的 ConfigChanges 属性以及横竖屏切换时候 Activity 的生命周期

Posted on 2011-04-17 16:00 charley_yang 阅读(12451) 评论(3) 编辑收藏举报

一、Activity 的 ConfigChanges 属性

官方解释：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

项目的AndroidManifest.xml文件配置方法:

<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>

二、横竖屏切换时候 Activity 的生命周期

测试代码：

public class AndroidLifecycle extends Activity {   
    private String TAG = "AndroidLifecycle";
    public void onCreate(Bundle savedInstanceState) {   
        Log.i(TAG,"AndroidLifecycle =======onCreate()========");   
        super.onCreate(savedInstanceState);   
        setContentView(R.layout.main);   
    }   
    
    @Override  
    protected void onSaveInstanceState(Bundle outState) {   
        Log.i(TAG,"AndroidLifecycle =======onSaveInstanceState()========");   
        super.onSaveInstanceState(outState);   
    }   
    
    @Override  
    protected void onRestoreInstanceState(Bundle outState) {   
        Log.i(TAG,"AndroidLifecycle=======onRestoreInstanceState()========");   
        super.onRestoreInstanceState(outState);   
    }   
    
    @Override  
    public void onConfigurationChanged(Configuration newConfig) {   
        Log.i(TAG,"AndroidLifecycle =======onConfigurationChanged()========");   
        super.onConfigurationChanged(newConfig);   
    }   
    
    // Called after onCreate — or after onRestart when the activity had been   
    // stopped, but is now again being displayed to the user. It will be   
    // followed by onResume   
    protected void onStart() {   
        Log.i(TAG,"AndroidLifecycle =======onStart()========");   
        super.onStart();   
    }   
    
    // Called after onRestoreInstanceState, onRestart, or onPause, for your   
    // activity to start interacting with the user   
    protected void onResume() {   
        Log.i(TAG,"AndroidLifecycle =======onResume()========");   
        super.onResume();   
    }   
    
    // Called as part of the activity lifecycle when an activity is going into   
    // the background, but has not (yet) been killed   
    protected void onPause() {   
        Log.i(TAG,"AndroidLifecycle =======onPause()========");   
        super.onPause();   
    }   
    
    // Called when you are no longer visible to the user. You will next receive   
    // either onRestart, onDestroy, or nothing, depending on later user   
    // activity.   
    protected void onStop() {   
        Log.i(TAG,"AndroidLifecycle =======onStop()========");   
        super.onStop();   
    }   
    
    // Perform any final cleanup before an activity is destroyed   
    protected void onDestroy() {   
        Log.i(TAG,"AndroidLifecycle =======onDestroy()========");   
        super.onDestroy();   
    }   
    
    // Called after onStop when the current activity is being re-displayed to   
    // the user (the user has navigated back to it). It will be followed by   
    // onStart and then onResume   
    protected void onRestart() {   
        Log.i(TAG,"AndroidLifecycle =======onRestart()========");   
        super.onRestart();   
    }   
}

Activity属性配置：

<application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:name=".AndroidLifecycle"
                  android:label="@string/app_name"
                  android:configChanges="orientation|keyboardHidden">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
 
    </application>

在 Android 2.2 模拟器上测试结果为：

1、不设置Activity的android:configChanges时：

Simulator_切换到横屏

Simulator_切换到竖屏

模拟器这种情况切屏会重新调用各个生命周期，切横屏时会生命周期执行一次，切竖屏时生命周期会执行两次，且横竖屏onConfigurationChanged未被调用。但是在HTC DESIRE HD(G10) 这款手机上测试结果为：生命周期都只执行一次，且横竖屏onConfigurationChanged未被调用。

2、设置Activity的android:configChanges="orientation"时：

Simulator_orientation_切换到横屏

Simulator_orientation_切换到竖屏

模拟器这种情况切屏还是会重新调用各个生命周期，切横屏onConfigurationChanged未执行、竖屏时onConfigurationChanged执行1次。但是在HTC DESIRE HD(G10) 这款手机上测试结果为：生命周期未发生变化，且横竖屏onConfigurationChanged都只执行一次。

3、设置Activity的android:configChanges="orientation|keyboardHidden"时： Simulator_orientation_keyboardHidden_切换到横屏

Simulator_orientation_keyboardHidden_切换到竖屏

模拟器这种情况切屏不会重新调用各个生命周期，切横屏时onConfigurationChanged会执行1次，切竖屏时onConfigurationChanged方法调用2次。但是在HTC DESIRE HD(G10) 这款手机上测试结果为：横竖屏onConfigurationChanged都只执行一次。

结论：可以看出在G10这款真机上测试的结果比模拟器更加合理。