How to disable Mobile Data on Android

Question

Quick back story before someone tells me to buy an app. =)

I just got an EVO and it chews through the battery fairly quick. I downloaded JuiceDefender to manage

Answer 1

Starting from 'Gingerbread' you can use the IConnectivityManager.setMobileDataEnabled() method. It's hidden in API, but can be accessed with reflection. http://grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/2.2_r1.1/android/net/ConnectivityManager.java#376

With this method you can change the system setting: 'Settings -> Wireless & network -> Mobile network settings -> Data Enabled'

Code example:

private void setMobileDataEnabled(Context context, boolean enabled) {
    final ConnectivityManager conman = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    final Class conmanClass = Class.forName(conman.getClass().getName());
    final Field iConnectivityManagerField = conmanClass.getDeclaredField("mService");
    iConnectivityManagerField.setAccessible(true);
    final Object iConnectivityManager = iConnectivityManagerField.get(conman);
    final Class iConnectivityManagerClass = Class.forName(iConnectivityManager.getClass().getName());
    final Method setMobileDataEnabledMethod = iConnectivityManagerClass.getDeclaredMethod("setMobileDataEnabled", Boolean.TYPE);
    setMobileDataEnabledMethod.setAccessible(true);

    setMobileDataEnabledMethod.invoke(iConnectivityManager, enabled);
}

Also you need the CHANGE_NETWORK_STATE permission.

Needless to say that this approach might not work in future android versions. But I guess that applications such as '3G watchdog', 'APNdroid' or 'DataLock' work this way.

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UPDATE:
setMobileDataEnabled method is no longer available on Lollipop