9
Ich habe ein paar listView-Aktivitäten geschrieben, als Beweis für mein Konzept, dass ich es tun könnte. Nun habe ich Probleme beim Laden einer ListView-Aktivität in eine einzelne Registerkarte für eine App mit mehreren Tabs, die sowohl Swiping als auch Tab-Auswahl für die Navigation ermöglicht. Ich erhalte den Fehler "Der Konstruktor ListView_Adapter (MainActivity.DummySectionFragment) ist nicht definiert", wenn ich versuche, den Code dafür zu schreiben. Ich bin ein Anfänger, und ich habe hier in den letzten paar Tagen ziemlich hart gelauert. Jede Hilfe wird geschätzt.Aufruf von benutzerdefiniertem ListView-Adapter aus Fragmentklasse Hauptaktivität
TL; DR: Ich bin ein n00b, und ich kann dieses Problem nicht herausfinden.
My Custom Liste Adapter
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);
}
}
}
Meine Hauptaktivität
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;
}
}
}