Question

我有10个片段列表。我能够刷卡并更新当前片段的值。在每个片段的顶部，我有一个数字列表，如page1，page2，page3 ... page15 所以现在我也想跳进点击的页面片段。所以我正在使用

viewPagerInstance.setCurrentItem(int position)

如果我跳到当前页面的右页左侧，它就有效。但如果我点击另一页，就像我在第2页，并想去page10。它给我空指针异常。我的资源（按钮）出现null错误。 onCreateView是否正常工作？因为所有资源都已初始化。所以它不应该是空的。

请帮助专家

我的适配器

public class MyPageAdapter extends FragmentStatePagerAdapter {
private List<Fragment> fragments;

public MyPageAdapter(FragmentManager fm, List<Fragment> fragments) {
    super(fm);
    this.fragments = fragments;
}

@Override
public Fragment getItem(int position) {
    return this.fragments.get(position);
}

@Override
public int getCount() {
    return this.fragments.size();
}

onCreateView

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    mView = inflater.inflate(R.layout.scorecardtabswingfragment,
            container, false);


    puttsBtnList = new ArrayList<Button>();
    puttsBtnList.add((Button) mView.findViewById(R.id.puttsBtn0));
    puttsBtnList.add((Button) mView.findViewById(R.id.puttsBtn1));
    puttsBtnList.add((Button) mView.findViewById(R.id.puttsBtn2));
    puttsBtnList.add((Button) mView.findViewById(R.id.puttsBtn3));
    puttsBtnList.add((Button) mView.findViewById(R.id.puttsBtn4));
    puttsBtnList.add((Button) mView.findViewById(R.id.puttsBtn5));
    puttsBtnList.add((Button) mView.findViewById(R.id.puttsBtn6));
    puttsBtnList.add((Button) mView.findViewById(R.id.puttsBtn7));
    puttsBtnList.add((Button) mView.findViewById(R.id.puttsBtn8));
    puttsBtnList.add((Button) mView.findViewById(R.id.puttsBtn9));
    puttsBtnList.add((Button) mView.findViewById(R.id.puttsBtn10));
    puttsBtnList.add((Button) mView.findViewById(R.id.puttsBtn11));
    puttsBtnList.add((Button) mView.findViewById(R.id.puttsBtn12));


    holeTitle = new TextView[18];
    holeTitle[0] = (TextView) mView.findViewById(R.id.tv_hole1);
    holeTitle[1] = (TextView) mView.findViewById(R.id.tv_hole2);
    holeTitle[2] = (TextView) mView.findViewById(R.id.tv_hole3);
    holeTitle[3] = (TextView) mView.findViewById(R.id.tv_hole4);
    holeTitle[4] = (TextView) mView.findViewById(R.id.tv_hole5);
    holeTitle[5] = (TextView) mView.findViewById(R.id.tv_hole6);
    holeTitle[6] = (TextView) mView.findViewById(R.id.tv_hole7);
    holeTitle[7] = (TextView) mView.findViewById(R.id.tv_hole8);
    holeTitle[8] = (TextView) mView.findViewById(R.id.tv_hole9);
    holeTitle[9] = (TextView) mView.findViewById(R.id.tv_hole10);
    holeTitle[10] = (TextView) mView.findViewById(R.id.tv_hole11);
    holeTitle[11] = (TextView) mView.findViewById(R.id.tv_hole12);
    holeTitle[12] = (TextView) mView.findViewById(R.id.tv_hole13);
    holeTitle[13] = (TextView) mView.findViewById(R.id.tv_hole14);
    holeTitle[14] = (TextView) mView.findViewById(R.id.tv_hole15);      
    holeTitle[15] = (TextView) mView.findViewById(R.id.tv_hole16);
    holeTitle[16] = (TextView) mView.findViewById(R.id.tv_hole17);
    holeTitle[17] = (TextView) mView.findViewById(R.id.tv_hole18);

    for(ImageButton b: firBtnList) {
        b.setOnClickListener(this);
    }

    for(Button b: penaltyBtnList) {
        b.setOnClickListener(this);
    }

    for(Button b : puttsBtnList) {
        b.setOnClickListener(this); 
        }

    for(Button b : storksBtnList) {
    b.setOnClickListener(this); 
    }

    for(TextView tv : holeTitle) {
        tv.setOnClickListener(this);
    }
    gpsBtn.setOnClickListener(this);

    toggleBtnPlayed.setOnClickListener(this);
    //TextView tv_hole = (TextView) mView.findViewById(R.id.tv_hole);
    //tv_hole.setText("Hole:"+getArguments().getInt("holeNum"));

    doneBtn.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View paramView) {

            if(APIUtil.isNeedForUpdate) 
                //update hole Golfer Scorecard.
                new UpdateHoleGolferScorecard(APIUtil.holeno_Update, APIUtil.score_Update, 
                        APIUtil.fir_Update, APIUtil.gir_Update, APIUtil.played_Update, APIUtil.putts_Update).execute();

            getActivity().finish();
            Intent intent = new Intent(getActivity(), ScorecardsActivity.class);
            intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
            startActivity(intent);      
        }
    });

    swingBtn = (Button) mView.findViewById(R.id.swingBtn);
    swingBtn.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {


        }
    });

    return mView;
}

更新

我正在使用可见属性的 setMenuVisibility 。我认为它首先调用onActivityCreated（）。我将所有代码放入onActivityCreated（）并立即工作。资源已初始化。但可以打电话

onActivityCreated first and after that setMenuVisibility. because for some reason i used it.

Answer 1

终于解决了我的问题。

mViewPager.setOffscreenPageLimit(17);

我加载了所有页面。

我正在使用setMenuVisibility（），因为我不想加载上一页和下一页的更新。我只想加载当前页面。所以当页面改变时它会先调用。

使用viewPagerInstance.setCurrentItem（int position）时出现片段空指针异常

1 个答案: