¿Cómo se seleccionan los elementos de la lista de una vista de lista con checkBox y Custom Adapter?

Question

Tengo un ListView con CheckBox en él. y estoy usando Custom Adapter para poblar el ListView.

En mi archivo xml tengo un Button en la parte inferior. lo que quiero es dejar que el usuario seleccione el número de filas en ListView y cuando hace clic en Button obtener la posición de los elementos seleccionados para que yo pueda obtener el objeto de una fila en particular para realizar más cálculos.

Answer 1

Below Snippet hace exactamente lo que desea.

package com.windrealm.android; 

import java.util.ArrayList; 
import java.util.Arrays; 
import java.util.List; 

import android.app.Activity; 
import android.content.Context; 
import android.os.Bundle; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.view.ViewGroup; 
import android.widget.AdapterView; 
import android.widget.ArrayAdapter; 
import android.widget.Button; 
import android.widget.CheckBox; 
import android.widget.ListView; 
import android.widget.TextView; 
import android.widget.Toast; 

public class PlanetsActivity extends Activity 
{ 

    private ListView mainListView; 
    private Planet[] planets; 
    private ArrayAdapter<Planet> listAdapter; 
    private Button check; 
    private Context context; 

    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) 
    { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     context = PlanetsActivity.this; 
     check = (Button) findViewById(R.id.check); 
     // Find the ListView resource. 
     mainListView = (ListView) findViewById(R.id.mainListView); 

     // When item is tapped, toggle checked properties of CheckBox and 
     // Planet. 
     mainListView 
       .setOnItemClickListener(new AdapterView.OnItemClickListener() 
       { 
        @Override 
        public void onItemClick(AdapterView<?> parent, View item, 
          int position, long id) 
        { 
         Planet planet = listAdapter.getItem(position); 
         planet.toggleChecked(); 
         PlanetViewHolder viewHolder = (PlanetViewHolder) item 
           .getTag(); 
         viewHolder.getCheckBox().setChecked(planet.isChecked()); 
        } 
       }); 

     // Create and populate planets. 
     planets = (Planet[]) getLastNonConfigurationInstance(); 
     if (planets == null) 
     { 
      planets = new Planet[] 
      { new Planet("Mercury"), new Planet("Venus"), new Planet("Earth"), 
        new Planet("Mars"), new Planet("Jupiter"), 
        new Planet("Saturn"), new Planet("Uranus"), 
        new Planet("Neptune"), new Planet("Ceres"), 
        new Planet("Pluto"), new Planet("Haumea"), 
        new Planet("Makemake"), new Planet("Eris") }; 
     } 
     ArrayList<Planet> planetList = new ArrayList<Planet>(); 
     planetList.addAll(Arrays.asList(planets)); 

     // Set our custom array adapter as the ListView's adapter. 
     listAdapter = new PlanetArrayAdapter(this, planetList); 
     mainListView.setAdapter(listAdapter); 

     check.setOnClickListener(new OnClickListener() 
     { 

      @Override 
      public void onClick(View view) 
      { 
       for (int i = 0; i < listAdapter.getCount(); i++) 
       { 
        Planet planet = listAdapter.getItem(i); 
        if (planet.isChecked()) 
        { 
         Toast.makeText(context, 
           planet.getName() + " is Checked!!", 
           Toast.LENGTH_SHORT).show(); 
        } 
       } 

      } 
     }); 
    } 

    /** Holds planet data. */ 
    private static class Planet 
    { 
     private String name = ""; 
     private boolean checked = false; 

     public Planet() 
     { 
     } 

     public Planet(String name) 
     { 
      this.name = name; 
     } 

     public Planet(String name, boolean checked) 
     { 
      this.name = name; 
      this.checked = checked; 
     } 

     public String getName() 
     { 
      return name; 
     } 

     public void setName(String name) 
     { 
      this.name = name; 
     } 

     public boolean isChecked() 
     { 
      return checked; 
     } 

     public void setChecked(boolean checked) 
     { 
      this.checked = checked; 
     } 

     public String toString() 
     { 
      return name; 
     } 

     public void toggleChecked() 
     { 
      checked = !checked; 
     } 
    } 

    /** Holds child views for one row. */ 
    private static class PlanetViewHolder 
    { 
     private CheckBox checkBox; 
     private TextView textView; 

     public PlanetViewHolder() 
     { 
     } 

     public PlanetViewHolder(TextView textView, CheckBox checkBox) 
     { 
      this.checkBox = checkBox; 
      this.textView = textView; 
     } 

     public CheckBox getCheckBox() 
     { 
      return checkBox; 
     } 

     public void setCheckBox(CheckBox checkBox) 
     { 
      this.checkBox = checkBox; 
     } 

     public TextView getTextView() 
     { 
      return textView; 
     } 

     public void setTextView(TextView textView) 
     { 
      this.textView = textView; 
     } 
    } 

    /** Custom adapter for displaying an array of Planet objects. */ 
    private static class PlanetArrayAdapter extends ArrayAdapter<Planet> 
    { 

     private LayoutInflater inflater; 

     public PlanetArrayAdapter(Context context, List<Planet> planetList) 
     { 
      super(context, R.layout.simplerow, R.id.rowTextView, planetList); 
      // Cache the LayoutInflate to avoid asking for a new one each time. 
      inflater = LayoutInflater.from(context); 
     } 

     @Override 
     public View getView(int position, View convertView, ViewGroup parent) 
     { 
      // Planet to display 
      Planet planet = (Planet) this.getItem(position); 

      // The child views in each row. 
      CheckBox checkBox; 
      TextView textView; 

      // Create a new row view 
      if (convertView == null) 
      { 
       convertView = inflater.inflate(R.layout.simplerow, null); 

       // Find the child views. 
       textView = (TextView) convertView 
         .findViewById(R.id.rowTextView); 
       checkBox = (CheckBox) convertView.findViewById(R.id.CheckBox01); 

       // Optimization: Tag the row with it's child views, so we don't 
       // have to 
       // call findViewById() later when we reuse the row. 
       convertView.setTag(new PlanetViewHolder(textView, checkBox)); 

       // If CheckBox is toggled, update the planet it is tagged with. 
       checkBox.setOnClickListener(new View.OnClickListener() 
       { 
        public void onClick(View v) 
        { 
         CheckBox cb = (CheckBox) v; 
         Planet planet = (Planet) cb.getTag(); 
         planet.setChecked(cb.isChecked()); 
        } 
       }); 
      } 
      // Reuse existing row view 
      else 
      { 
       // Because we use a ViewHolder, we avoid having to call 
       // findViewById(). 
       PlanetViewHolder viewHolder = (PlanetViewHolder) convertView 
         .getTag(); 
       checkBox = viewHolder.getCheckBox(); 
       textView = viewHolder.getTextView(); 
      } 

      // Tag the CheckBox with the Planet it is displaying, so that we can 
      // access the planet in onClick() when the CheckBox is toggled. 
      checkBox.setTag(planet); 

      // Display planet data 
      checkBox.setChecked(planet.isChecked()); 
      textView.setText(planet.getName()); 

      return convertView; 
     } 

    } 

    public Object onRetainNonConfigurationInstance() 
    { 
     return planets; 
    } 
} 

Answer 2

Para resolver este problema, tendrá que crear una clase personalizada de artículos que representará sus casillas individuales en la lista. El conjunto de estos elementos será utilizado por la clase de adaptador para mostrar sus casillas de verificación.

Esta clase de elemento tendrá una variable booleana isSelected que determinará si la casilla de verificación está seleccionada o no. Usted tendrá que ajustar el valor de esta variable en el método OnClick de su clase de adaptador personalizado

Por ejemplo

class CheckBoxItem{ 

    boolean isSelected; 


    public void setSelected(boolean val) { 
      this.isSelected = val; 
     } 

     boolean isSelected(){ 
      return isSelected; 

     } 

    } 

para su clase CustomAdapter que parecen siguiente:

public class ItemsAdapter extends ArrayAdapter implements OnClickListener { 

// you will have to initialize below in the constructor 
    CheckBoxItem items[]; 



    // You will have to create your check boxes here and set the position of your check box 
    /// with help of setTag method of View as defined in below method, you will use this later // in your onClick method 

    @Override 
     public View getView(int position, View convertView, ViewGroup parent) { 
      View v = convertView; 



      CheckBox cBox = null; 

      if (v == null) { 
       LayoutInflater vi = (LayoutInflater) apUI.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
       v = vi.inflate(R.layout.attachphoto, null);  

      } 



      CheckBoxItemItem it = items[position];  

      cBox =(CheckBox) v.findViewById(R.id.apCheckBox); 
      cBox.setOnClickListener(this); 
      cBox.setTag(""+position);  


      Log.d(TAG, " CHECK BOX IS: "+cBox+ " Check Box selected Value: "+cBox.isChecked()+" Selection: "+it.isSelected()); 
      if(cBox != null){ 
       cBox.setText(""); 
       cBox.setChecked(it.isSelected()); 
      }  


      return v; 
     } 


     public void onClick(View v) { 
      CheckBox cBox =(CheckBox) v.findViewById(R.id.apCheckBox); 
      int position = Integer.parseInt((String) v.getTag()); 

      Log.d(TAG, "CLicked ..."+cBox.isChecked()); 

      items[position].setSelected(cBox.isChecked());    
     } 

    } 

Más tarde will declarará y organizará su clase CheckBoxItem que será contenida por su clase Adapter, en este caso será una clase ItemsAdapter.

Luego, cuando el usuario presiona el botón, puede recorrer todos los elementos de la matriz y verificar cuál se selecciona utilizando el método isSelected() de la clase CheckBoxItem.

En su actividad que tendrá:

ArrayList getSelectedItems(){ 

ArrayList selectedItems = new ArrayList(); 

int size = items.length; 

     for(int i = 0; i<size; i++){ 
      CheckBoxItem cItem = items[i]; 
      if(cItem.isSelected()){     
       selectedItems.add(cItem);     
      }   
     } 

return selectedItems; 

} 

Answer 3

que tenían el mismo problema. Lo resolví de esta manera

public class myActivity extends Activity { 
//ActionBarSherlock mSherlock = ActionBarSherlock.wrap(this); 
public ListView listview; 
private ArrayList<Object> itemlist=new ArrayList<Object>(); 
Button button; 
private myAdapter adapter; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    listview=(ListView)findViewById(R.id.listview1); 
    button=(Button)findViewById(R.id.button1); 
    /*add some data to ur list*/ itemlist.add(something); 
    adapter=new Adapter(myActivity.this, 0, itemlist); 
    listview.setAdapter(adapter); 
    **listview.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE); 
    listview.setItemsCanFocus(false);** 
    button.setOnClickListner(new OnClickListner() 
    { 
    @Override 
    public void OnClick(View v) 
    { 
     /* this returns the checked item positions in the listview*/ 
     **ArrayList<Integer> itempositions=adapter.getcheckeditemcount();** 

    for(int i:itempositions) 
    { 
      /* This is the main part...u can retrieve the object in the listview which is checked and do further calculations with it*/ 
     **Object info=adapter.getItem(i);** 
          Log.d(TAG,"checked object info= ",info.something); 
       } 
    } 
    }); 
} 


private class myAdapter extends ArrayAdapter<Object> { 

    private Context context; 
    private ArrayList<Object> list; 
    **private ArrayList<Integer> checkedpositions;** 


    public myAdapter(Context localContext,int textViewResourceId, ArrayList<Object> objects) { 
     super(localContext,textViewResourceId,objects); 
     context = localContext; 
     this.list=objects; 
     this.checkedpositions=new ArrayList<Integer>(); 
     //Log.d("adapter","list size= "+objects.size()); 
    } 

@Override  
    public View getView(int position, View convertView, ViewGroup parent) { 

     ImageView picturesView; 
     View v = convertView; 
     TextView Mainitem; 
     final CheckBox check; 

     if (v == null) 
     { 
      LayoutInflater vi = (LayoutInflater)getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
      v = vi.inflate(R.layout.albumview, null); 


      Object item=list.get(position); 
      if(item!=null) 
      { 

       check = (CheckBox)v.findViewById(R.id.checkBox1); 
        /* set a tag for chekbox with the current view position */ 
       **check.setTag(position);** 
        /*set a onchecked change listner for listning to state of checkbox toggle */ 
       check.setOnCheckedChangeListener(new OnCheckedChangeListener() 
       { 
        @Override 
        public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) 
        {    
             /*get the tag of the checkbox...in this case this will give the (position of view)*/ 
         Object tag=check.getTag(); 
         if (isChecked) 
         { 
          // perform logic 
          count++; 
          Log.d("Checkbox","added "+tag); 
          checkedpositions.add((Integer) tag); 
         } 
         else 
         { 
          count--; 
          checkedpositions.remove(tag); 
          Log.d("Checkbox","removed "+(Integer)tag); 
         } 

       /* if u dont have a textview in ur listview then ignore this part */   
       Mainitem = (TextView) v.findViewById(R.id.textView1); 
       Mainitem.setText(item.Album_name); 

       } catch (IOException e) { 
        // TODO Auto-generated catch block 
        Log.d("error", "wall"); 
       } 

      } 

     } 

    return v; 

    } 
    /* Finally create a method which return the checkeditem postions in the listview */ 
**public ArrayList<Integer> getcheckeditemcount() 
{ 
    return this.checkedpositions; 
}** 

} 

} 

Espero que esto ayude.

Answer 4

En el método de la getView customadapter, hacer

//use the actual id of your checkbox of course 
Checkbox checkbox = (CheckBox)findViewById(R.id.checkbox); 
checkbox.setFocusable(false); 
checkbox.setFocusableInTouchMode(false); 

ahora la casilla de verificación se puede hacer clic como es el listitem.