public String getMsisdn(int slotId) {    return getLine1NumberForSubscriber(getSubIdForSlotId(slotId));  }

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

  public class RegisterMessage {   private static Context mContext;   private static TelephonyManager mTelephonyManager;   private ConnectivityManager mConnMngr;   private static SubscriptionManager mSubscriptionManager;   public RegisterMessage(Context context) {     mContext = context;     mTelephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);     if (mTelephonyManager == null) {       throw new Error("telephony manager is null");     }     mConnMngr = (ConnectivityManager) context         .getSystemService(Context.CONNECTIVITY_SERVICE);     mSubscriptionManager = SubscriptionManager.from(mContext);   } 

public String getMsisdn(int slotId) {//slotId 0為卡1 ，1為卡2   return getLine1NumberForSubscriber(getSubIdForSlotId(slotId)); }  rivate int getSubIdForSlotId(int slotId) {   int[] subIds = getSubId(slotId);   if (subIds == null || subIds.length < 1 || subIds[0] < 0) {     return -1;   }   MLog.d("getSubIdForSlotId = "+subIds[0]);   return subIds[0]; } private static int[] getSubId(int slotId) {   Method declaredMethod;   int[] subArr = null;   try {     declaredMethod = Class.forName("android.telephony.SubscriptionManager").getDeclaredMethod("getSubId", new Class[]{Integer.TYPE});     declaredMethod.setAccessible(true);     subArr = (int[]) declaredMethod.invoke(mSubscriptionManager,slotId);   } catch (ClassNotFoundException e) {     e.printStackTrace();     declaredMethod = null;   } catch (IllegalArgumentException e2) {     e2.printStackTrace();     declaredMethod = null;   } catch (NoSuchMethodException e3) {     e3.printStackTrace();     declaredMethod = null;   } catch (ClassCastException e4) {     e4.printStackTrace();     declaredMethod = null;   } catch (IllegalAccessException e5){     e5.printStackTrace();     declaredMethod = null;   }catch (InvocationTargetException e6){     e6.printStackTrace();     declaredMethod = null;   }   if(declaredMethod == null) {     subArr = null;   }   MLog.d("getSubId = "+subArr[0]);   return subArr; } private String getLine1NumberForSubscriber(int subId){   Method method;   String status = null;   try {     method = mTelephonyManager.getClass().getMethod("getLine1NumberForSubscriber", int.class);     method.setAccessible(true);     status = String.valueOf(method.invoke(mTelephonyManager, subId));   } catch (NoSuchMethodException e) {     e.printStackTrace();   } catch (IllegalAccessException e) {     e.printStackTrace();   } catch (IllegalArgumentException e) {     e.printStackTrace();   } catch (InvocationTargetException e) {     e.printStackTrace();   }   MLog.d("getLine1NumberForSubscriber = "+status);   return status; }