import com.android.internal.telephony.ITelephony;
import android.os.ServiceManager;

    private boolean phoneIsInUse() {
        boolean phoneInUse = false;
        try {
            ITelephony phone = ITelephony.Stub.asInterface(ServiceManager.checkService("phone"));
            if (phone != null) phoneInUse = !phone.isIdle();
        } catch (RemoteException e) {
            Log.w(TAG, "phone.isIdle() failed", e);
        }
        return phoneInUse;
    }

参照：http://www.myexception.cn/android/922374.html

4.4原生应用获取通话状态