从片段类主要活动调用自定义ListView适配器

我已经写了一些listView活动,作为我可以做的一个概念certificate。 现在,我无法将listView活动加载到具有多个选项卡的应用程序的单个选项卡中,从而允许导航的滑动和选项卡select。 当我尝试为它编写代码时,出现错误“构造函数ListView_Adapter(MainActivity.DummySectionFragment)未定义”。 我是一个初学者,过去几天我在这里潜伏得很厉害。 任何帮助表示赞赏。

TL; DR:我是一个n00b,我不知道这个问题。

我的自定义列表适配器

import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ArrayAdapter; import android.widget.TextView; public class CustomListViewAdapter extends ArrayAdapter<String> { public CustomListViewAdapter (Context c) { super(c, R.layout.list_cell); } @Override public View getView(int position, View convertView, ViewGroup parent) { View row = convertView; ListView_Text holder = null; if (row == null) { LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE); row = inflater.inflate(R.layout.list_cell, parent, false); holder = new ListView_Text(row); row.setTag(holder); } else { holder = (ListView_Text) row.getTag(); } holder.populateFrom(getItem(position)); return row; } static class ListView_Text { private TextView cell_name = null; ListView_Text(View row) { cell_name = (TextView) row.findViewById(R.id.list_cell_name); } void populateFrom(String index) { cell_name.setText(index); } } } 

我的主要活动

  import java.util.Locale; import android.app.ActionBar; import android.app.ActionBar.Tab; import android.app.FragmentTransaction; import com.example.twigglebeta2.ListView_Adapter; import android.os.Bundle; import android.support.v4.app.Fragment; import android.support.v4.app.FragmentActivity; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentPagerAdapter; import android.support.v4.app.NavUtils; import android.support.v4.view.ViewPager; import android.view.Gravity; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.widget.ListView; import android.widget.TextView; public class MainActivity extends FragmentActivity implements ActionBar.TabListener { private static ListView_Adapter listViewAdapter; private ListView listView; SectionsPagerAdapter mSectionsPagerAdapter; ViewPager mViewPager; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); // Set up the action bar. final ActionBar actionBar = getActionBar(); actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS); // Create adapter mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager()); // Set up the ViewPager with the sections adapter. mViewPager = (ViewPager) findViewById(R.id.pager); mViewPager.setAdapter(mSectionsPagerAdapter); // Switch tab selection to match current page when swiped mViewPager.setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() { @Override public void onPageSelected(int position) { actionBar.setSelectedNavigationItem(position); } }); // Create a tab for each 'count' in the activity from getCount() for (int i = 0; i < mSectionsPagerAdapter.getCount(); i++) { Tab thisTab = actionBar.newTab(); thisTab.setText(mSectionsPagerAdapter.getPageTitle(i)); thisTab.setTabListener(this); actionBar.addTab(thisTab); } } @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar if it is present. getMenuInflater().inflate(R.menu.main, 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.title_section1).toUpperCase(l); case 1: return getString(R.string.title_section2).toUpperCase(l); case 2: return getString(R.string.title_section3).toUpperCase(l); } return null; } } /** * A dummy fragment representing a section of the app, but that simply * displays dummy text. */ public static 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_main_dummy,container, false); switch(getArguments().getInt(ARG_SECTION_NUMBER)){ case 1: //The constructor ListView_Adapter(MainActivity.DummySectionFragment) is undefined listViewAdapter = new ListView_Adapter(this); ListView listView = (ListView) rootView.findViewById(R.id.listView1); for (int i=0;i<20;i++) { listViewAdapter.add("this Index : "+i); } return listView; } TextView dummyTextView = (TextView) rootView.findViewById(R.id.section_label); dummyTextView.setText(Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER))); return rootView; } } } 

Solutions Collecting From Web of "从片段类主要活动调用自定义ListView适配器"

而不是listViewAdapter = new ListView_Adapter(this); ,你应该尝试listViewAdapter = new ListView_Adapter(getActivity().getBaseContext());

问题是你正在传递一个片段到构造函数,而不是一个Activity上下文。