Android中的BackStack方法和ViewPager的问题

Question

>我有一个包含框架布局的活动。在其中，我有一个片段，其中包含ViewPager，里面有两个不同的片段。当我按下给定片段中的按钮时，我将帧布局容器替换为新片段。现在，当我按下 ViewPager 视图时，它没有恢复，它已经消失了。

这是第一个片段：

public class CurrencyFragment extends BaseFragment {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setHasOptionsMenu(true);
    }

    @Override
    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
        super.onCreateOptionsMenu(menu, inflater);
    }
    // onclick method for the refresh button on the action bar
    // the method itself calls the anoteher method getCurrency()
    // it also sets visibility to progress bar and loading text and
    // sets invisible to the listview
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case R.id.action_refresh:

            Log.i("TAG", "refresh pressed =>");
            return true;
        }
        // Handle your other action bar items...
        return super.onOptionsItemSelected(item);
    }

    // oncreateView() where the basic view is created
    @Override
    public View onCreateView(final LayoutInflater inflater,
            ViewGroup container, Bundle savedInstanceState) {
        final View view = inflater.inflate(R.layout.fragment_currency_layout,
                container, false);

        mBankName = (TextView) view.findViewById(R.id.Currency_name);
        mBuySell = (LinearLayout) view.findViewById(R.id.Buy_Sell);
        mButtonBuy = (TextView) view.findViewById(R.id.Button_buy);
        mButtonSell = (TextView) view.findViewById(R.id.Button_sell);
        mViewpager = (ViewPager) view.findViewById(R.id.Detailpager);

        Bundle bundle = getArguments();
        if(bundle != null){
        Bank object = (Bank) bundle.getSerializable("message");
        mBankName.setText(object.getName());
        code = object.getCode();
        }
        testadapter = new ViewPagerAdapter(getFragmentManager(),code);
        mViewpager.setAdapter(testadapter);
        if(code.equals("NBG")){
            mBuySell.setVisibility(View.GONE);
             mViewpager.setOnTouchListener(new View.OnTouchListener() {
                @Override
                public boolean onTouch(View v, MotionEvent event) {
                    // TODO Auto-generated method stub
                    return false;
                }
            });
        }else{
            mBuySell.setVisibility(View.VISIBLE);
        }
        mViewpager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                // TODO Auto-generated method stub
                if (position == 0){
                    mButtonBuy.setBackgroundColor(Color.parseColor("#2FCEB8"));
                    mButtonSell.setBackgroundColor(Color.parseColor("#333333"));
                }
                else{
                    mButtonSell.setBackgroundColor(Color.parseColor("#2FCEB8"));
                    mButtonBuy.setBackgroundColor(Color.parseColor("#333333"));
                }
            }
            @Override
            public void onPageScrollStateChanged(int arg0) {
                // TODO Auto-generated method stub
            }
            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {
                // TODO Auto-generated method stub
            }

        });


        mButtonBuy.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                mButtonBuy.setBackgroundColor(Color.parseColor("#2FCEB8"));
                mButtonSell.setBackgroundColor(Color.parseColor("#333333"));
                mViewpager.setCurrentItem(0);

            }
        });
        mButtonSell.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                mButtonSell.setBackgroundColor(Color.parseColor("#2FCEB8"));
                mButtonBuy.setBackgroundColor(Color.parseColor("#333333"));
                mViewpager.setCurrentItem(1);

            }
        });
        return view;
    }  
}

之后被替换为另一个

public class DetailedCalculator extends BaseFragment {
    private View detailedView;
    private TextView mButtonBuy;
    private TextView mButtonSell;
    private TextView mDetailedBank;
    private ViewPager mDetailpager;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        DetailPagerAdapter myAdapter = new DetailPagerAdapter(getFragmentManager());
        detailedView = inflater.inflate(R.layout.detail_buy_sell, container, false);
        mButtonBuy = (TextView) detailedView.findViewById(R.id.Detail_buying);
        mButtonSell = (TextView) detailedView.findViewById(R.id.Detail_selling);
        mDetailedBank = (TextView) detailedView.findViewById(R.id.Detail_BankNAme);
        mDetailpager = (ViewPager) detailedView.findViewById(R.id.Detailpager);
        mDetailpager.setAdapter(myAdapter);

        mDetailpager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                // TODO Auto-generated method stub
                if(position == 0){
                    mButtonBuy.setBackgroundColor(Color.parseColor("#2FCEB8"));
                    mButtonSell.setBackgroundColor(Color.parseColor("#333333"));
                }
                else{
                    mButtonSell.setBackgroundColor(Color.parseColor("#2FCEB8"));
                    mButtonBuy.setBackgroundColor(Color.parseColor("#333333"));
                }
            }
            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {
                // TODO Auto-generated method stub
            }
            @Override
            public void onPageScrollStateChanged(int arg0) {
                // TODO Auto-generated method stub
            }
        });
        mButtonBuy.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                mButtonBuy.setBackgroundColor(Color.parseColor("#2FCEB8"));
                mButtonSell.setBackgroundColor(Color.parseColor("#333333"));
                mDetailpager.setCurrentItem(0);
            }
        });
        mButtonSell.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                mButtonSell.setBackgroundColor(Color.parseColor("#2FCEB8"));
                mButtonBuy.setBackgroundColor(Color.parseColor("#333333"));
                mDetailpager.setCurrentItem(1);
            }
        });

        return detailedView;

    }

}

Answer 1

尝试在包含 ViewPager 的片段中使用 getChildFragmentManager() 而不是 getFragmentManager()：

testadapter = new ViewPagerAdapter(getFragmentManager(),code);

自

testadapter = new ViewPagerAdapter(getChildFragmentManager(),code);