1. 目的

廣播攔截中，注意識別預設電話程序和外撥事件不可攔截

2. 原始碼

2.1 攔截判斷

    // check out call for phone app
    if ("android".equals(callerApp)
        && intent != null && Intent.ACTION_NEW_OUTGOING_CALL.equals(intent.getAction())
        && mSystemPreferredConfig.isDefaultPhoneApp(targetApp)) {

        if (DEBUG) Slog.d(TAG, "start phone app for out call:" + targetApp);
        return true;
    }
 

2.2 是否為預設電話程序

    private String mDefaultPhoneApp;

    public boolean isDefaultPhoneApp(String pkgName) {
        return (pkgName != null
            && mDefaultPhoneApp != null
            && pkgName.equals(mDefaultPhoneApp));
    }
    
    private SettingsObserver mSettingsObserver;

    class SettingsObserver extends ContentObserver {
        private final ContentResolver mResolver;
        final Uri defaultSMSUri = Settings.Secure.getUriFor(
                // 預設簡訊
                Settings.Secure.SMS_DEFAULT_APPLICATION);
        final Uri defaultPhoneUri = Settings.Secure.getUriFor(
                // 預設電話
                Settings.Secure.DIALER_DEFAULT_APPLICATION);

        SettingsObserver(Handler handler, ContentResolver resolver) {
            super(handler);
            mResolver = resolver;
            // mResolver.registerContentObserver(Settings.Secure.getUriFor(
            //        Settings.Secure.ENABLED_ACCESSIBILITY_SERVICES), false, this);
            if (defaultSMSUri != null)
                mResolver.registerContentObserver(defaultSMSUri, false, this, UserHandle.USER_ALL);
            if (defaultPhoneUri != null)
                mResolver.registerContentObserver(defaultPhoneUri, false, this, UserHandle.USER_ALL);
        }

        @Override 
        public void onChange(boolean selfChange, Uri uri) {
            // getEnabledServiceList();
            try {
                if (defaultSMSUri !=null && defaultSMSUri.equals(uri)) {
                    mDefaultSmsComp = SmsApplication.getDefaultSmsApplication(mContext, true);
                    if (DEBUG) Slog.d(TAG, "mDefaultSmsComp:" + mDefaultSmsComp + " mDefaultPhoneApp:" + mDefaultPhoneApp);
                } else if (defaultPhoneUri != null && defaultPhoneUri.equals(uri)) {
                    mDefaultPhoneApp = DefaultDialerManager.getDefaultDialerApplication(mContext);
                    if (DEBUG) Slog.d(TAG, "mDefaultSmsComp:" + mDefaultSmsComp + " mDefaultPhoneApp:" + mDefaultPhoneApp);
                }
            } catch (Exception e) {}

        }
    }