Question

How would I make my app launch when a secret code, such as *#*#12345#*#* is entered into the dialer?

I couldn’t find a solution in the Android docs.

Answer 1

This is how I did it:

I changed my main activity to have no intent-filters:

<activity
            android:name=".ParentTrap"
            android:label="@string/title_activity_parent_trap"
            android:theme="@android:style/Theme.Holo" >
        </activity>

I then made a broadcast receiver with the intent filter action: android.provider.Telephony.SECRET_CODE

I then added data to it. The entire thing is below:

<receiver android:name=".ParentTrap$Launch" >
            <intent-filter>
                <action android:name="android.provider.Telephony.SECRET_CODE" />

                <data
                    android:host="(secret code)"
                    android:scheme="android_secret_code" />
            </intent-filter>
        </receiver>

Once done, make a class (I made the Launch class in my main class, extending BroadCast Receiver), then in the onReceive class, fire an intent to launch the activity.

Then typing *#*#(secret code)#*#* into the dialer will launch the app.