【问题标题】:Add listview adapter to layout of Fragment将 listview 适配器添加到 Fragment 的布局
【发布时间】:2014-02-27 11:40:12
【问题描述】:

我想动态生成我的 Listview 的内容,但在这种情况下不知道该怎么做,因为我在 Fragment 中而不是在主 Activity 中。 这是代码:

public class Contacts extends FragmentActivity implements ActionBar.TabListener {

SectionsPagerAdapter mSectionsPagerAdapter;

/**
 * The {@link ViewPager} that will host the section contents.
 */
ViewPager mViewPager;
ListView myListView; // Listview here
ListView listview;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_contacts);

    // Set up the action bar.
    final ActionBar actionBar = getActionBar();
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

    // Create the adapter that will return a fragment for each of the three
    // primary sections of the app.
    mSectionsPagerAdapter = new SectionsPagerAdapter(
            getSupportFragmentManager());

    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.setAdapter(mSectionsPagerAdapter);
    getActionBar().setDisplayShowTitleEnabled(false);
    getActionBar().setDisplayUseLogoEnabled(false);
    getActionBar().setDisplayShowHomeEnabled(false);
    // When swiping between different sections, select the corresponding
    // tab. We can also use ActionBar.Tab#select() to do this if we have
    // a reference to the Tab.
    mViewPager
            .setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
                @Override
                public void onPageSelected(int position) {
                    actionBar.setSelectedNavigationItem(position);
                }
            });

    // For each of the sections in the app, add a tab to the action bar.
    for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) {
        // Create a tab with text corresponding to the page title defined by
        // the adapter. Also specify this Activity object, which implements
        // the TabListener interface, as the callback (listener) for when
        // this tab is selected.
        actionBar.addTab(actionBar.newTab()
                .setText(mSectionsPagerAdapter.getPageTitle(i))
                .setTabListener(this));
    }

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.contacts, menu);
    return true;
}

@Override
public void onTabSelected(ActionBar.Tab tab,
        FragmentTransaction fragmentTransaction) {
    // When the given tab is selected, switch to the corresponding page in
    // the ViewPager.
    mViewPager.setCurrentItem(tab.getPosition());
}

@Override
public void onTabUnselected(ActionBar.Tab tab,
        FragmentTransaction fragmentTransaction) {
}

@Override
public void onTabReselected(ActionBar.Tab tab,
        FragmentTransaction fragmentTransaction) {
}

/**
 * A {@link FragmentPagerAdapter} that returns a fragment corresponding to
 * one of the sections/tabs/pages.
 */
public class SectionsPagerAdapter extends FragmentPagerAdapter {

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

    @Override
    public Fragment getItem(int position) {
        // getItem is called to instantiate the fragment for the given page.
        // Return a DummySectionFragment (defined as a static inner class
        // below) with the page number as its lone argument.
        Fragment fragment = new DummySectionFragment();
        Bundle args = new Bundle();
        args.putInt(DummySectionFragment.ARG_SECTION_NUMBER, position + 1);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public int getCount() {
        // Show 3 total pages.
        return 3;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        Locale l = Locale.getDefault();
        switch (position) {
        case 0:

            return getString(R.string.contacts).toUpperCase(l);
        case 1:
            return getString(R.string.title_section2).toUpperCase(l);
        case 2:
            return getString(R.string.title_section3).toUpperCase(l);
        }
        return null;
    }
}

private class StableArrayAdapter extends ArrayAdapter<String> {

    HashMap<String, Integer> mIdMap = new HashMap<String, Integer>();

    public StableArrayAdapter(Context context, int textViewResourceId,
            List<String> objects) {
        super(context, textViewResourceId, objects);
        for (int i = 0; i < objects.size(); ++i) {
            mIdMap.put(objects.get(i), i);
        }
    }

    @Override
    public long getItemId(int position) {
        String item = getItem(position);
        return mIdMap.get(item);
    }

    @Override
    public boolean hasStableIds() {
        return true;
    }

}

}

还有片段:

public class DummySectionFragment extends Fragment {
/**
 * The fragment argument representing the section number for this fragment.
 */
public static final String ARG_SECTION_NUMBER = "section_number";

public DummySectionFragment() {
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_contacts_dummy,
            container, false);
    if (getArguments().getInt(ARG_SECTION_NUMBER) == 2) {

        rootView = inflater.inflate(R.layout.contact_section, container,
                false);
        ListView listView1 = (ListView) rootView
                .findViewById(R.id.listview);

    } else {
        TextView dummyTextView = (TextView) rootView
                .findViewById(R.id.section_label);
        dummyTextView.setText(Integer.toString(getArguments().getInt(
                ARG_SECTION_NUMBER)));
        String[] values = new String[] { "Android", "iPhone",
                "WindowsMobile", "Blackberry", "WebOS", "Ubuntu",
                "Windows7", "Max OS X", "Linux", "OS/2", "Ubuntu",
                "Windows7", "Max OS X", "Linux", "OS/2", "Ubuntu",
                "Windows7", "Max OS X", "Linux", "OS/2", "Android",
                "iPhone", "WindowsMobile" };

        final ArrayList<String> list = new ArrayList<String>();
        for (int i = 0; i < values.length; ++i) {
            list.add(values[i]);
        }
        ArrayAdapter<String> adapter = new ArrayAdapter<String>     (this,R.id.listview);
    }

    return rootView;
}
}

以下是布局文件:

<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".Contacts" />

第二种布局:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".Contacts$DummySectionFragment" >

<TextView
    android:id="@+id/section_label"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

<ListView

    android:id="@+id/listview"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content" />

【问题讨论】:

  • 你应该使用 ListFragment 而不是 Fragment,如果你想使用动态添加元素到一个 Activity,那个 Activity 应该是 ListActivity
  • 非常感谢。你能给我一个我无法让它工作的例子吗?

标签: android android-layout android-listview android-fragments fragment


【解决方案1】:

这并不难。 Listactivity 或 activity,fragment 或 listfragment 都可以。也许 list* 会有更少的代码。

在您的活动或片段中,设置适配器,例如,您使用 ArrayAdapter。如果您的列表有一个删除选项,您需要使用LinkedList 来提供元素,或者您应该使用ArrayList 作为附加选项。并将适配器设置为列表视图。

每次有新元素到来或删除时,调用列表(LinkedList 或 Arraylist)addremove,然后调用适配器的notifyDataSetChanged 方法。

我假设你忘记将你的列表(LinkedList 或 Arraylist)添加到 ArrayAdapter 的构造函数中,就像这样,new ArrayAdapter&lt;String&gt;(..., ..., ..., List&lt;?&gt;...)

就是这样,请尝试一下!

【讨论】:

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