Question

在android开发中，当我使用

时，pointView是一个TextView

final CommunityFragment CommunityFragment = new CommunityFragment();
pointView.setText(String.valueOf(CommunityFragment.points));

它在社区片段类中带来了整数的整数值。更改该值后，如何获取更新值？下面的完整代码：

class TotalPointsMenu extends Activity{
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.total_points_menu);
        // TODO Auto-generated method stub
        final CommunityFragment CommunityFragment = new CommunityFragment();
        TextView rankView = (TextView) findViewById(R.id.Ranks);
        final TextView pointView = (TextView) findViewById(R.id.Points);
        Button refreshButton = (Button) findViewById(R.id.refreshButton);
        pointView.setText(String.valueOf(CommunityFragment.points));
        refreshButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                pointView.setText(String.valueOf(CommunityFragment.points));
                Toast.makeText(getApplicationContext(), String.valueOf(CommunityFragment.points), Toast.LENGTH_LONG).show();
            }
        });
        int points = CommunityFragment.points;
        pointView.setText(String.valueOf(points));
        if(points >= 20 && points < 45){
            rankView.setText(R.string.pos2);
        }
        if(points >= 45 && points < 65){
            rankView.setText(R.string.pos3);
        }
        if(points >= 65 && points < 80){
            rankView.setText(R.string.pos4);
        }
        if(points >= 80 && points < 110){
            rankView.setText(R.string.pos5);
        }
        if(points >= 110){
            rankView.setText(R.string.pos6);
        }
    }
}

CommunityFragment：

class CommunityFragment extends Fragment{
    public int points = 0;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
    }
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){
        View view = inflater.inflate(R.layout.community_fragment, container, false);
        Button Tgiven = (Button) view.findViewById(R.id.Tgiven);
        Tgiven.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                points += 20;
                Toast.makeText(getActivity(), "You gained 20 points!", Toast.LENGTH_LONG).show();
            }
        });
        Button fbPage = (Button) view.findViewById(R.id.fbPage);
        fbPage.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent openURL = new Intent(Intent.ACTION_VIEW, Uri.parse("https://www.facebook.com/pages/FBLA-Intro-to-It/294112347403691"));
                startActivity(openURL);
            }
        });
        Button Qgiven = (Button) view.findViewById(R.id.Qgiven);
        Qgiven.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                points += 10;
                Toast.makeText(getActivity(), "You gained 10 points!", Toast.LENGTH_LONG).show();
            }
        });
        Button Qhelp = (Button) view.findViewById(R.id.Qhelp);
        Qhelp.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                points += 5;
                Toast.makeText(getActivity(), "You gained 5 points!", Toast.LENGTH_LONG).show();
                Intent openURL = new Intent(Intent.ACTION_VIEW, Uri.parse("https://www.facebook.com/pages/FBLA-Intro-to-It/294112347403691"));
                startActivity(openURL);
            }
        });
        Button QhelpedEnter = (Button) view.findViewById(R.id.QhelpedEnter);
        final TextView Qhelped = (TextView) view.findViewById(R.id.Qhelped);
        QhelpedEnter.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                points += 5;
                Toast.makeText(getActivity(), "You gained 5 points!", Toast.LENGTH_LONG).show();
                Qhelped.setText("");
            }
        });
        Button Thelp = (Button) view.findViewById(R.id.Thelp);
        Thelp.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                points += 10;
                Toast.makeText(getActivity(), "You gained 10 points!", Toast.LENGTH_LONG).show();
                Intent openURL = new Intent(Intent.ACTION_VIEW, Uri.parse("https://www.facebook.com/pages/FBLA-Intro-to-It/294112347403691"));
                startActivity(openURL);
            }
        });
        return view;
    }
}

MainFragment（转到活动适配器）

class MainFragment extends FragmentActivity{
    ViewPager ViewPager = null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ViewPager= (ViewPager) findViewById(R.id.pager);
        FragmentManager fragmentManager=getSupportFragmentManager();
        ViewPager.setAdapter(new AdapterActivity(fragmentManager));
    }

活动适配器（然后就像社区一样有家庭和资源片段，但它们是分开的）

public class AdapterActivity extends FragmentStatePagerAdapter{
    public AdapterActivity(FragmentManager fm){
        super(fm);
    }
    @Override
    public Fragment getItem(int i){
        Fragment fragment=null;
        switch(i){
        case 0:
            fragment=new HomeFragment();
            break;
        case 1:
            fragment=new CommunityFragment();
            break;
        case 2:
            fragment=new ResourcesFragment();
            break;
        }
        return fragment;
    }
    @Override
    public int getCount(){
        return 3;
    }
    @Override
    public CharSequence getPageTitle(int position){
        switch(position){
        case 0:
            return "Home Page";
        case 1:
            return "Community";
        case 2:
            return "Resources";
        }
        return null;
    }
}

Answer 1

首先，我建议您更改CommunityFragment变量的名称。

final CommunityFragment CommunityFragment = new CommunityFragment();

将变量命名为类名是一个坏习惯。（这就是我要求发布其余代码的原因，因为如果您的point被声明为static，则可能会发生冲突。

我看到的问题是CommunityFragment变量是指您使用new运算符创建的实例，但它永远不会添加到FragmentManager的屏幕中。我认为您在屏幕上看到的片段是{strong> CommunityFragment类的另一个实例，可能是在扩充XML时创建的。

此外，在rankView视图中设置文字的代码仅出现在onCreate()上，因此您的rankView将不会更新。只要确保你知道这一点。

从另一个类获取整数的更新值

1 个答案: