Start / stop built-in Wi-Fi / USB tethering from c

问题:

How can I start or stop the built-in tethering in Android 2.2 from my application?

回答1:

There is a non-public Tethering API in the ConnectivityManager. As shown above you can use reflection to access it. I tried this on a number of Android 2.2 phones, and it works on all of them (my HTC turns on tethering but does NOT show this in the status bar..., so check from the other end). Below is some rough code which emits debugging stuff and turns on tethering on usb0.

ConnectivityManager cman = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);

Method[] methods = cman.getClass().getDeclaredMethods();
for (Method method : methods) {
    if (method.getName().equals("getTetherableIfaces")) {
        try {
            String[] ifaces = (String[]) method.invoke(cman);
            for (String iface : ifaces) {
                Log.d("TETHER", "Tether available on " + iface);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    if (method.getName().equals("isTetheringSupported")) {
        try {
            boolean supported = (Boolean) method.invoke(cman);
            Log.d("TETHER", "Tether is supported: " + (supported ? "yes" : "no"));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    if (method.getName().equals("tether")) {
        Log.d("TETHER", "Starting tether usb0");
        try {
            int result = (Integer) method.invoke(cman, "usb0");
            Log.d("TETHER", "Tether usb0 result: " + result);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Please note: this code requires the following permissions to work:

android.permission.ACCESS_NETWORK_STATE
android.permission.CHANGE_NETWORK_STATE

回答2:

I answered this question here. In short, it is possible, here is the code:

private void setWifiTetheringEnabled(boolean enable) {
    WifiManager wifiManager = (WifiManager) getSystemService(WIFI_SERVICE);

    Method[] methods = wifiManager.getClass().getDeclaredMethods();
    for (Method method : methods) {
        if (method.getName().equals("setWifiApEnabled")) {
            try {
                method.invoke(wifiManager, null, enable);
            } catch (Exception ex) {
            }
            break;
        }
    }
}

Your app should have the following permission:

android.permission.CHANGE_WIFI_STATE

回答3:

There are no public APIs in the Android SDK for managing the tethering -- sorry!

回答4:

I used the code from Android How to turn on hotspot in Android Programmatically! and I enable the portable hotspot for android 4.2. Here's the code.

WifiManager wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
// TODO Auto-generated method stub
WifiConfiguration wifi_configuration = null;
wifiManager.setWifiEnabled(false);

try 
{
  //USE REFLECTION TO GET METHOD "SetWifiAPEnabled"
Method method=wifiManager.getClass().getMethod("setWifiApEnabled", WifiConfiguration.class, boolean.class);
method.invoke(wifiManager, wifi_configuration, true);
} 
catch (NoSuchMethodException e){
// TODO Auto-generated catch block
  e.printStackTrace();
}catch (IllegalArgumentException e) {
    // TODO Auto-generated catch block
e.printStackTrace();
}catch (IllegalAccessException e) {
    // TODO Auto-generated catch block
 e.printStackTrace();
}catch (InvocationTargetException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
}