在android的手機裏,進入撥號程序,輸入*#*#4636#*#* 能夠看到一個測試應用。java
查看Phone的源代碼,有一個函數專門處理*#*# 開頭,#*#*結尾的撥號字符串。android
SpecialCharSequenceMgr.javaapp
/**
* Handles secret codes to launch arbitrary activities in the form of *#*#<code>#*#*.
* If a secret code is encountered an Intent is started with the android_secret_code://<code>
* URI.
*
* @param context the context to use
* @param input the text to check for a secret code in
* @return true if a secret code was encountered
*/
static private boolean handleSecretCode(Context context, String input) {
// Secret codes are in the form *#*#<code>#*#*
int len = input.length();
if (len > 8 && input.startsWith("*#*#") && input.endsWith("#*#*")) {
Intent intent = new Intent(Intents.SECRET_CODE_ACTION,
Uri.parse("android_secret_code://" + input.substring(4, len - 4)));
context.sendBroadcast(intent);
return true;
}
return false;
}ide
這樣,根據android_secret_code就能夠查到系統所用的全部隱形字符串。函數
b090@test-desktop:~/Android_Code$ find . -name "AndroidManifest.xml" | xargs grep android_secret_code
./packages/providers/CalendarProvider/AndroidManifest.xml: <data android:scheme="android_secret_code" android:host="225" />
./packages/apps/Settings/AndroidManifest.xml: <data android:scheme="android_secret_code" android:host="4636" />
./packages/apps/VoiceDialer/AndroidManifest.xml: <data android:scheme="android_secret_code" android:host="8351" />
./packages/apps/VoiceDialer/AndroidManifest.xml: <data android:scheme="android_secret_code" android:host="8350" />測試
能夠看到,系統代碼裏面有225/4636/8351/8350隱形字符串。.net
若是用戶想要開發應用程序支持特殊的隱形字串,只須要照貓畫虎在AndroidManifest.xml添加Filter就能夠了。code
例如:orm
<receiver android:name="TestingSettingsBroadcastReceiver">
<intent-filter>
<action android:name="android.provider.Telephony.SECRET_CODE" />
<data android:scheme="android_secret_code" android:host="4636" />
</intent-filter>
</receiver>xml
有沒有什麼方法,能看看到系統所支持的intent以及其所支持的參數呢?