android - 将数据从 Activity 传递到 Fragments

Question

我已经完成了一个简单的应用程序，可以通过 json 列出 mysql 数据库中的所有产品。当我单击特定产品时，它会将我带到显示其详细信息的 Activity 。现在我更改了我的应用程序，这样当我从列表中单击特定产品时，它会转到一个包含 3 个选项卡的 fragment 。我已经创建了所有相关 fragment ，一切正常。只有当我尝试将数据从列表中的所有产品 Activity 传递到详细信息 fragment Activity 时，它才不起作用。如何将数据从列出所有产品的主屏幕传递到显示详细信息的 3 个 fragment ？

进一步说明:

没有框架的工作示例:Main Activity显示所有产品并在选择单个产品后将其传递给Details Activity-> Details Activity从Main Activity获取数据并显示Details

现在我有了显示所有产品的主要 Activity 。我是将数据传递给 -> "public class EmpresaDetailsActivity extends FragmentActivity implements ActionBar.TabListener { etc"还是必须将其传递给我创建的所有其他 3 个单个 fragment ？

(旧方法)列出所有产品:

@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.all_empresas);

        empresaList = new ArrayList<HashMap<String, String>>();

        // Get listview
        ListView lv = getListView();

        // on selecting single empresa
        // launching Empresa Details Screen
        lv.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                                    int position, long id) {
                // getting values from selected ListItem
                String eid = ((TextView) view.findViewById(R.id.eid)).getText().toString();
                String marca = ((TextView) view.findViewById(R.id.marca)).getText().toString();
                String investimento = ((TextView) view.findViewById(R.id.investimento)).getText().toString();
                String marcatotal = ((TextView) view.findViewById(R.id.marcatotal)).getText().toString();

                // Starting new intent
                Intent in = new Intent(getApplicationContext(),EmpresaDetailsActivity.class);
                // sending data to next activity
                in.putExtra(TAG_EID, eid);
                in.putExtra(TAG_MARCA, marca);
                in.putExtra(TAG_INVESTIMENTO, investimento);
                in.putExtra(TAG_MARCATOTAL, marcatotal);

                // starting new activity and expecting some response back
                startActivity(in);
            }
        });

        // Loading empresa in Background Thread
        new LoadAllEmpresa().execute();
    }

(老办法)单品详情:

public class EmpresaDetailsActivity  extends Activity {

    // JSON node keys
    private static final String TAG_EID = "eid";
    private static final String TAG_MARCA = "marca";
    private static final String TAG_INVESTIMENTO = "investimento";
    private static final String TAG_MARCATOTAL = "marcatotal";
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.details_empresa);

        // getting intent data
        Intent in = getIntent();

        // Get JSON values from previous intent
        String eid = in.getStringExtra(TAG_EID);
        String marca = in.getStringExtra(TAG_MARCA);
        String investimento = in.getStringExtra(TAG_INVESTIMENTO);
        String marcatotal = in.getStringExtra(TAG_MARCATOTAL);

        // Displaying all values on the screen
        TextView lblEid = (TextView) findViewById(R.id.showEid);
        TextView lblName = (TextView) findViewById(R.id.showMarca);
        TextView lblInvestimento = (TextView) findViewById(R.id.showInvestimento);
        TextView lblMarcatotal = (TextView) findViewById(R.id.showMarcaTotal);

        lblEid.setText(eid);
        lblName.setText(marca);
        lblInvestimento.setText(investimento);
        lblMarcatotal.setText(marcatotal);
    }
}

具有 3 个 fragment 的新详细信息类:

public class EmpresaDetailsActivity extends FragmentActivity implements ActionBar.TabListener {

    private ViewPager viewPager;
    private TabsPagerAdapter mAdapter;
    private ActionBar actionBar;
    // Tab titles
    private String[] tabs = { "Apresentação", "Ficha Técnica", "Pedir Informação" };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.details_global_frag);

        // Initilization
        viewPager = (ViewPager) findViewById(R.id.pager);
        actionBar = getActionBar();
        mAdapter = new TabsPagerAdapter(getSupportFragmentManager());

        viewPager.setAdapter(mAdapter);
        actionBar.setHomeButtonEnabled(false);
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

        // Adding Tabs
        for (String tab_name : tabs) {
            actionBar.addTab(actionBar.newTab().setText(tab_name)
                    .setTabListener(this));
        }

        /**
         * on swiping the viewpager make respective tab selected
         * */
        viewPager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {

            @Override
            public void onPageSelected(int position) {
                // on changing the page
                // make respected tab selected
                actionBar.setSelectedNavigationItem(position);
            }

            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {
            }

            @Override
            public void onPageScrollStateChanged(int arg0) {
            }
        });
    }

    @Override
    public void onTabReselected(Tab tab, FragmentTransaction ft) {
    }

    @Override
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        // on tab selected
        // show respected fragment view
        viewPager.setCurrentItem(tab.getPosition());
    }

    @Override
    public void onTabUnselected(Tab tab, FragmentTransaction ft) {
    }

}

TabsPagerAdapter 类:

public class TabsPagerAdapter extends FragmentPagerAdapter {

    public TabsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int index) {

        switch (index) {
        case 0:
            // Top Rated fragment activity
            return new ApresentacaoFragment();
        case 1:
            // Games fragment activity
            return new FichaTecnicaFragment();
        case 2:
            // Movies fragment activity
            return new PedirInformacaoFragment();
        }

        return null;
    }

    @Override
    public int getCount() {
        // get item count - equal to number of tabs
        return 3;
    }

}

3 个 fragment 中的 1 个示例:

public class ApresentacaoFragment extends Fragment {

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

        View rootView = inflater.inflate(R.layout.fragment_apresentacao, container, false);

        return rootView;
    }
}

Answer 1

在您的 onItemClick() Activity 中，在启动 fragment 之前:

Bundle args = new Bundle();
args.putString(TAG_EID, eid);
args.putString(TAG_MARCA, marca);
args.putString(TAG_INVESTIMENTO, invetstimento);
args.putString(TAG_MARCATOTLA, marcatotal);
yourFragment.setArguments(args);

在您的 fragment OnCreateView() 上:

Bundle args = getArguments();
String marca = args.getString(TAG_MARCA);
// and so on...

更清楚地说，这里是您应该如何在 Activity/Fragment 之间传递数据。

• Activity --> Fragment:使用 Bundle 和 setArguments。 (如上图)
• Activity --> Activity :使用 Intent 和 putExtra。
• fragment --> Activity :使用界面。 Avtivity 应该实现它，Fragment 应该调用它。

---

检查新代码后:

1. 将您的字符串包装在一个 Bundle 中，并将其从 MainActivity 传递到您的 EmpresaDetailsActivity。
2. 使用 getIntent().getExtras() 获取它。

3. 将您的 TabsPagerAdapter 更改为:

   public class TabsPagerAdapter extends FragmentPagerAdapter {
   
   private Bundle args;
   
   public TabsPagerAdapter(FragmentManager fm, Bundle args) {
       super(fm);
       this.args = args;
   }
   
   @Override
   public Fragment getItem(int index) {
   
   switch (index) {
   case 0:
       // Top Rated fragment activity
       ApresentacaoFragment apresentacaoFragment = new ApresentacaoFragment();
       apresentacaoFragment.setArguments(args);
       return apresentacaoFragment;
   case 1:
       // Games fragment activity
       // do the same as above with your Games fragmnet class
   case 2:
       // Movies fragment activity
       // ...
   }
   
   return null;
    }
   
    @Override
   public int getCount() {
       // get item count - equal to number of tabs
       return 3;
   }   
   }
   

   1. 当实例化适配器时，将包传递给它的构造函数。
   2. 在您的 fragment 类中使用 getArguments() 来获取包，您就完成了。