2013-10-19 24 views
16

Questa è la mia prima esperienza con Android. Sto cercando di aggiungere elementi al mio ListView. Uso le schede e l'unico modo per vedere che l'elemento è stato aggiunto è quello di cambiare scheda e quindi tornare alla prima scheda.Aggiungi elementi a ListView - Android

Ho cercato in giro, e ho sempre trovato

adapter.notifyDataSetChanged(); 

ma non funziona per me.

Ho creato il progetto con, come ho detto, Fixed Tabs + Swipe. Voglio semplicemente avere listview su quali righe hanno un EditText, una Spinner e un Button. Nella parte inferiore del frammento utilizzato per la scheda, ho un pulsante ImageButton. Voglio cliccarci sopra e avere una nuova riga.

mio adattatore personalizzato:

package com.andreapivetta.uconverter; 

import java.util.ArrayList; 

import android.content.Context; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.ArrayAdapter; 

public class CustomAdapter extends ArrayAdapter<String> { 
private final Context context; 
private final int resourceID; 

    public CustomAdapter(Context context, int resource, ArrayList<String> bah) { 
     super(context, resource, bah); 

     this.context = context; 
     this.resourceID = resource; 
    } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
     View rowView = inflater.inflate(resourceID, parent, false); 

     return rowView; 
    } 
} 

fragment_main_dummy.xml

<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=".MainActivity$DummySectionFragment" > 

<ListView 
    android:id="@+id/unitListView" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" > 
</ListView> 

<ImageButton 
    android:id="@+id/moreImageButton" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 

    android:layout_alignParentBottom="true" 
    android:layout_alignParentRight="true" 

    android:contentDescription="@string/image_button_delete" 
    android:src="@android:drawable/ic_input_add" /> 

</RelativeLayout> 

Row.xml

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
      android:layout_width="match_parent" 
      android:layout_height="match_parent"> 

<TextView 
    android:id="@+id/textView1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentLeft="true" 
    android:layout_alignParentTop="true" /> 

<EditText 
    android:id="@+id/unitEditText" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignParentLeft="true" 
    android:layout_below="@+id/textView1" 
    android:ems="10" 
    android:inputType="numberDecimal" > 

    <requestFocus /> 
</EditText> 

<Spinner 
    android:id="@+id/unitSpinner" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignBottom="@+id/imageButton1" 
    android:layout_marginBottom="15dp" 
    android:layout_toRightOf="@+id/unitEditText" /> 

<ImageButton 
    android:id="@+id/imageButton1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_alignBottom="@+id/unitEditText" 
    android:layout_alignParentRight="true" 

    android:onClick="removeItem" 

    android:contentDescription="@string/image_button_delete" 
    android:src="@android:drawable/ic_menu_delete" /> 

</RelativeLayout> 

MainActivity ...

public class MainActivity extends FragmentActivity implements 
    ActionBar.TabListener { 

/** 
* The {@link android.support.v4.view.PagerAdapter} that will provide 
* fragments for each of the sections. We use a 
* {@link android.support.v4.app.FragmentPagerAdapter} derivative, which 
* will keep every loaded fragment in memory. If this becomes too memory 
* intensive, it may be best to switch to a 
* {@link android.support.v4.app.FragmentStatePagerAdapter}. 
*/ 
SectionsPagerAdapter mSectionsPagerAdapter; 

/** 
* The {@link ViewPager} that will host the section contents. 
*/ 
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 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); 

    // 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.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 4 total pages. 
     return 4; 
    } 

    @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); 
     case 3: 
      return getString(R.string.title_section4).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. 
    */ 
    ArrayList<String> myStringArray1 = new ArrayList<String>();//new String[]{"Egzo","Eg","Egzona"}; 
    String[] myStringArray2 = new String[]{"aaa","bbb","ccc"}; 
    String[] myStringArray3 = new String[]{"ddd","eeee"}; 
    String[] myStringArray4 = new String[]{"Cia","ci","Ciao"}; 
    public static ArrayAdapter<String> adapter; 

    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); 
     //TextView dummyTextView = (TextView) rootView.findViewById(R.id.section_label); 
     //dummyTextView.setText(Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER))); 

     // ListView 
     ListView unitListView = (ListView) rootView.findViewById(R.id.unitListView); 

     switch(getArguments().getInt(ARG_SECTION_NUMBER)) { 
     case 1: 
      myStringArray1.add("mmm"); 

      adapter = new CustomAdapter(getActivity(), R.layout.row, myStringArray1); 
      unitListView.setAdapter(adapter); 
      break; 
     case 2: 
      adapter = new ArrayAdapter<String>(getActivity(), R.layout.row, R.id.textView1, myStringArray2); 
      unitListView.setAdapter(adapter); 
      break; 
     case 3: 
      adapter = new ArrayAdapter<String>(getActivity(), R.layout.row, R.id.textView1, myStringArray3); 
      unitListView.setAdapter(adapter); 
      break; 
     case 4: 
      adapter = new ArrayAdapter<String>(getActivity(), R.layout.row, R.id.textView1, myStringArray4); 
      unitListView.setAdapter(adapter); 
      break; 
     } 
     unitListView.setOnItemClickListener(listViewOnClickListener); 

     // ImageButton 
     ImageButton moreImageButton = (ImageButton) rootView.findViewById(R.id.moreImageButton); 
     moreImageButton.setOnClickListener(moreListener); 


     return rootView; 
    } 

    public OnClickListener moreListener = new OnClickListener(){ 

     @Override 
     public void onClick(View v) { 
      // TODO Auto-generated method stub 

      myStringArray1.add("Andrea"); 
      adapter.clear(); 
      adapter.addAll(myStringArray1); 
      adapter.notifyDataSetChanged(); 
     } 

    }; 

    public OnItemClickListener listViewOnClickListener = new OnItemClickListener() { 

     @Override 
     public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, 
       long arg3) { 
      // TODO Auto-generated method stub 

     } 

    }; 
} 

} 

Nota che sto lavorando solo con la prima scheda in questo momento ...

Cosa sto facendo male? :)

+1

L'adattatore personalizzato dovrebbe essere riutilizzare il 'convertView' invece di sputare fuori un nuova vista ogni volta. Non sono sicuro se ciò lo risolverà ma è certamente un problema. –

+0

Grazie, ma per ora voglio solo che funzioni, quindi correggerò i problemi di prestazioni :) – andrew

risposta

24
ListView myListView = (ListView) rootView.findViewById(R.id.myListView); 
ArrayList<String> myStringArray1 = new ArrayList<String>(); 
myStringArray1.add("something"); 
adapter = new CustomAdapter(getActivity(), R.layout.row, myStringArray1); 
myListView.setAdapter(adapter); 

Prova in questo modo

public OnClickListener moreListener = new OnClickListener() { 

    @Override 
    public void onClick(View v) { 
     adapter = null; 
     myStringArray1.add("Andrea"); 
     adapter = new CustomAdapter(getActivity(), R.layout.row, myStringArray1); 
     myListView.setAdapter(adapter); 
     adapter.notifyDataSetChanged(); 
    }  
}; 
+0

imposta l'adattatore della visualizzazione elenco dopo aver chiamato notifyDataSetChanged(). Ciò significa scambiare le ultime 2 righe di codice nel codice sopra indicato da Amit. –

+0

Grazie, funziona! Potresti spiegare perché prima avevo delle eccezioni? – andrew

3

Provate questo funzionerà

public class Third extends ListActivity { 
private ArrayAdapter<String> adapter; 
private List<String> liste; 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_third); 
    String[] values = new String[] { "Android", "iPhone", "WindowsMobile", 
       "Blackberry", "WebOS", "Ubuntu", "Windows7", "Max OS X", 
       "Linux", "OS/2" }; 
    liste = new ArrayList<String>(); 
    Collections.addAll(liste, values); 
    adapter = new ArrayAdapter<String>(this, 
       android.R.layout.simple_list_item_1, liste); 
    setListAdapter(adapter); 
} 
@Override 
    protected void onListItemClick(ListView l, View v, int position, long id) { 
    liste.add("Nokia"); 
    adapter.notifyDataSetChanged(); 
    } 
} 
0
public OnClickListener moreListener = new OnClickListener() { 

    @Override 
     public void onClick(View v) { 
      adapter.add("aaaa") 
     } 
} 
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