android 开发者选项

默认User版本没有“开发者选项”，我们可以通过点击版本号7次来显示开发者模式，今天来看下代码中是如何处理的：

首先是

ackages/apps/Settings/src/com/android/settings/Settings.java的初始化处理：

布尔值showDev是否默认显示“开发者选项”：

 final boolean showDev = mDevelopmentPreferences.getBoolean(                DevelopmentSettings.PREF_SHOW,                android.os.Build.TYPE.equals("eng"));

如果想让开发者选项默认显示，不需要点击7次版本号，可直接将showDev置为true即可：

final boolean showDev = true; 

如果showDev为false，则在如下代码中隐藏“开发者选项”：

if (id == R.id.development_settings) {                if (!showDev) {                    target.remove(i);                }            } 

下面看一下点击版本号显示开发者选项的部分：

代码路径：packages/apps/Settings/src/com/android/settings/DeviceInfoSettings.java

首先是定义点击次数：

static final int TAPS_TO_BE_A_DEVELOPER = 7;

点击版本号的处理逻辑，若mDevHitCountdown小于0，则表示”开发者选项“已经显示，参考Resume函数的处理：

if (preference.getKey().equals(KEY_BUILD_NUMBER)) {            // Don't enable developer options for secondary users.            if (UserHandle.myUserId() != UserHandle.USER_OWNER) return true;            if (mDevHitCountdown > 0) {                if (mDevHitCountdown == 1) {                    if (super.ensurePinRestrictedPreference(preference)) {                        return true;                    }                }                mDevHitCountdown--;                if (mDevHitCountdown == 0) {                    getActivity().getSharedPreferences(DevelopmentSettings.PREF_FILE,                            Context.MODE_PRIVATE).edit().putBoolean(                                    DevelopmentSettings.PREF_SHOW, true).apply();                    if (mDevHitToast != null) {                        mDevHitToast.cancel();                    }                    mDevHitToast = Toast.makeText(getActivity(), R.string.show_dev_on,                            Toast.LENGTH_LONG);                    mDevHitToast.show();                } else if (mDevHitCountdown > 0                        && mDevHitCountdown < (TAPS_TO_BE_A_DEVELOPER-2)) {                    if (mDevHitToast != null) {                        mDevHitToast.cancel();                    }                    mDevHitToast = Toast.makeText(getActivity(), getResources().getQuantityString(                            R.plurals.show_dev_countdown, mDevHitCountdown, mDevHitCountdown),                            Toast.LENGTH_SHORT);                    mDevHitToast.show();                }            } else if (mDevHitCountdown < 0) {                if (mDevHitToast != null) {                    mDevHitToast.cancel();                }                mDevHitToast = Toast.makeText(getActivity(), R.string.show_dev_already,                        Toast.LENGTH_LONG);                 mDevHitToast.show();            }        } 

Resume函数：

@Override    public void onResume() {        super.onResume();        PreferenceGroup parentPreference = getPreferenceScreen();        mDevHitCountdown = getActivity().getSharedPreferences(DevelopmentSettings.PREF_FILE,                Context.MODE_PRIVATE).getBoolean(DevelopmentSettings.PREF_SHOW,                        android.os.Build.TYPE.equals("eng")) ? -1 : TAPS_TO_BE_A_DEVELOPER;        mDevHitToast = null;    }