Activity的ConfigChanges属性

原文： http://www.cnblogs.com/charley_yang/archive/2011/04/17/2018940.html

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。