Android dual SIM -> change network

Question

Starting SDK 22, Android officially support Dual-SIM and provide some documentation.

I would like to know if it is possible for an app to change wich SIM should access the network. For example I have a One Plus One 3T phone running Nougat and I use two SIM cards. Going into settings, I can manually change / select which SIM card to use to access the network.

Is it possible to achieve this ?

Thanks !

Answer 1

The solution I found for Android 7.1.1 API 25 is using SubscriptionManager and reflection api.

Note that you have to install your app in /system/priv-app/

You can do this through adb root.

Make sure you have in your AndroidManifest.xml

<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.MODIFY_PHONE_STATE"/>
<uses-permission android:name="android.permission.WRITE_APN_SETTINGS"/>

The code is the following

The only thing this code does is exchange the sim data

private Integer subActual = null;
private Integer sim1 = null;
private Integer sim2 = null;
private SubscriptionInfo simInfo1;
private SubscriptionInfo simInfo2;
private Boolean dualSim;

SubscriptionManager subscriptionManager = SubscriptionManager.from(this);

    @SuppressLint("MissingPermission")
    List smList = subscriptionManager.getActiveSubscriptionInfoList();

    Method[] smMethods = subscriptionManager.getClass().getMethods();

    dualSim = smList.size() == 2;

    if (dualSim) {
        simInfo1 = (SubscriptionInfo) smList.get(0);
        simInfo2 = (SubscriptionInfo) smList.get(1);
        sim1 = simInfo1.getSubscriptionId();
        sim2 = simInfo2.getSubscriptionId();
    }

    for (Method m : smMethods) {
        if (m.getName().equals(("getDefaultDataSubscriptionId"))) {
            try {
                subActual = (int) m.invoke(subscriptionManager);
            } catch (Exception e) {

            }
        }
    }

    for (Method m : smMethods) {
        if (m.getName().equals("setDefaultDataSubId") && dualSim) {
            try {
                if (subActual == sim1) {
                    m.invoke(subscriptionManager, sim2);
                }
                if (subActual == sim2) {
                    m.invoke(subscriptionManager, sim1);
                }
            } catch (Exception e) {

            }
        }
    }