Android從ListView獲取複選框信息

Question

我有一個帶有多個複選框的ListView（每個列表項都有一個）。創建包含所選複選框信息的數組的最佳方法是什麼？

例如，這是一個列表。

Item 1 "Ham" Checked 
    Item 2 "Turkey" NotChecked 
    Item 3 "Bread" Checked 

我想創建一個包含「火腿」和「火雞」

Answer 1

如果您使用ListView的內置有setChoiceMode複選框（）方法，那麼你只需要調用getCheckedItemIds()或getCheckedItemPositions()。

public class Example extends Activity implements OnClickListener { 
    ListView mListView; 
    String[] array = new String[] {"Ham", "Turkey", "Bread"}; 

    @Override 
    public void onCreate(Bundle savedInstanceState) 
    { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 

     ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_checked, array); 

     mListView = (ListView) findViewById(R.id.list); 
     mListView.setAdapter(adapter); 
     mListView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE); 

     Button button = (Button) findViewById(R.id.button); 
     button.setOnClickListener(this); 
    } 

    public void onClick(View view) { 
     SparseBooleanArray positions = mListView.getCheckedItemPositions(); 
     int size = positions.size(); 
     for(int index = 0; index < size; index++) { 
      Log.v("Example", "Checked: " + array[positions.keyAt(index)]); 
     } 
    } 
} 

如果適配器綁定到光標，那麼這變得更加實用。

Answer 2

您可以創建一個ArrayList和那麼無論項目的用戶選中它們添加到ArrayList中的數組。

下面的代碼片段正是你想要的。

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()) 
        { 
              //Add this item in ArrayList 
         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; 
    } 
}