无法在onActivityResult（...）中将FragmentAdapter重置为ViewPager

我在ViewPager中使用FragmentActivity，在onCreate（...）方法中我将FragmentPagerAdapter适配器设置为ViewPager它在这里运行正常但是当我尝试在onActivityResult（...）方法中将新的FragmentPagerAdapter重置为ViewPager时只有构造函数适配器正在调用和公共Fragment getItem（int position）;没有被调用，因为我得到片段null . 因此，当我在onActivityResult（...）中重置适配器后尝试获取当前可见片段时，我将变为null .

这就是我在onCreate中所做的事情：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    //Remove title bar
    this.requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.blocked_list);

    lable = getIntent().getStringExtra("ItemName");
    blocked_list_lable = (TextView) findViewById(R.id.blocked_list_lable);
    add_Contact = (Button) findViewById(R.id.add);
    mAdapter = new CallManagerFragmentAdapter(getSupportFragmentManager(), lable);

    mPager = (ViewPager)findViewById(R.id.pager);
    mPager.setAdapter(mAdapter);

    mIndicator = (TitlePageIndicator)findViewById(R.id.indicator);
    mIndicator.setViewPager(mPager);
    addNewContact = new AddNewContactPopup(this);
    addNewContact.setPopDimentions((int) TypedValue.applyDimension(
            TypedValue.COMPLEX_UNIT_DIP, 320, getResources()
                    .getDisplayMetrics()), (int) TypedValue.applyDimension(
            TypedValue.COMPLEX_UNIT_DIP, 280, BlackList.this.getResources()
                    .getDisplayMetrics()));
    blocked_list_lable.setText(lable);
    setListener(add_Contact);


 }

这就是我在onActivityResult中所做的事情：

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == CALLS_SMS_LOGS || requestCode == CONTACTS_LIST) {
        if (resultCode == RESULT_OK) {
            String result = data.getStringExtra("dbUpdateSucess");
            if (result.equals("Success")) {
                Logger.log("Info", TAG,
                        "Update from call logs is Sucess...");
                //Cursor cursor = getCursor(lable);
                mAdapter = new CallManagerFragmentAdapter(getSupportFragmentManager(), lable);
                mPager.setAdapter(mAdapter);
                //adapter = new BlackListAdapter(this, cursor);
                //blocked_List.setAdapter(adapter);
                return;
            } else {
                Logger.log("Error", TAG, "Update from call logs failed...");
            }
        }
    }
}

这是我的FragmentAdapter代码;

class CallManagerFragmentAdapter extends FragmentPagerAdapter implements IconPagerAdapter {

protected static final String[] CONTENT = new String[] { "Call Logs", "Blacklist No"};
protected static final String[] BLACK_LIST_SMS_CONTENT = new String[] { "SMS Logs", "Blacklist No"};
protected static final String[] WHITELIST_CALLS_CONTENT = new String[] { "Call Logs", "Whitelist No"};
protected static final String[] WHITELIST_SMS_CONTENT = new String[] { "SMS Logs", "Whitelist No"};
protected static final String[] PRIVATE = new String[] { "SMS Logs", "Call Logs", "Private No"};
protected static final int[] ICONS = new int[] {
        R.drawable.perm_group_calendar,
        R.drawable.perm_group_camera/*,
        R.drawable.perm_group_device_alarms,
        R.drawable.perm_group_location*/
};

private int mCount = CONTENT.length;
private String lable;
public HashMap<Integer, CallManagerFragment> fragmentMap;

public CallManagerFragmentAdapter(FragmentManager fm, String lable) {
    super(fm);
    this.lable = lable;
    fragmentMap = new HashMap<Integer, CallManagerFragment>();
}

@Override
public Fragment getItem(int position) {
    String content;

    CallManagerFragment fragment = CallManagerFragment.newInstance(content, lable);
    fragmentMap.put(position, fragment);
    return fragment;
}

public CallManagerFragment getFragment(int key) {
  return fragmentMap.get(key);
}

public void destroyItem(ViewGroup container, int position, Object object) {
super.destroyItem(container, position, object);
fragmentMap.remove(position);
}


@Override
public int getCount() {
    return mCount;
}

@Override
public CharSequence getPageTitle(int position) {
    if(lable.equals("Whitelist Calls")) {
        return CallManagerFragmentAdapter.WHITELIST_CALLS_CONTENT[position % WHITELIST_CALLS_CONTENT.length];
    } else if (lable.equals("Whitelist SMS")) {
        return WHITELIST_SMS_CONTENT[position % WHITELIST_SMS_CONTENT.length];
    } else if(lable.equals("Private")) {
        return PRIVATE[position % PRIVATE.length];
    } else if(lable.equals("Blacklist SMS")) {
        return BLACK_LIST_SMS_CONTENT[position % BLACK_LIST_SMS_CONTENT.length];
    }
  return CallManagerFragmentAdapter.CONTENT[position % CONTENT.length];
}


public int getIconResId(int index) {
  return ICONS[index % ICONS.length];
}

public void setCount(int count) {
    if (count > 0 && count <= 10) {
        mCount = count;
        notifyDataSetChanged();
    }
}

}