【发布时间】：2012-06-10 07:12:29
【问题描述】：
我有一个ListView，上面有CheckBox。我正在使用Custom Adapter 填充ListView。
在我的xml 文件中，底部有一个Button。我想要的是让用户在ListView 中选择行数，当他/她点击Button 时，获取所选项目的位置，以便我可以获取特定行的对象以进行进一步计算。
【问题讨论】：
标签： android listview checkbox adapter
【发布时间】：2012-06-10 07:12:29
【问题描述】：
Below Snippet 完全符合您的要求。
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;
}
}
【讨论】：
要解决这个问题，您必须创建一个自定义 Item 类，该类将代表您在列表中的各个复选框。然后适配器类将使用这些项目的数组来显示您的复选框。
这个 Item 类将有一个布尔变量 isSelected，它将确定复选框是否被选中。您必须在自定义适配器类的 OnClick 方法中设置此变量的值
举例
class CheckBoxItem{
boolean isSelected;
public void setSelected(boolean val) {
this.isSelected = val;
}
boolean isSelected(){
return isSelected;
}
}
对于您的 CustomAdapter 类，如下所示：
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());
}
}
稍后您将声明 CheckBoxItem 类的数组，该类将包含在您的 Adapter 类中，在这种情况下，它将是 ItemsAdapter 类。
然后当用户按下按钮时，您可以遍历数组中的所有项，并使用 CheckBoxItem 类的 isSelected() 方法检查选择了哪一项。
在您的活动中，您将拥有：
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;
}
【讨论】：
我遇到了完全相同的问题。我是这样解决的
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;
}**
}
}
我希望这会有所帮助。
【讨论】：
在customadapter的getview方法中，做
//use the actual id of your checkbox of course
Checkbox checkbox = (CheckBox)findViewById(R.id.checkbox);
checkbox.setFocusable(false);
checkbox.setFocusableInTouchMode(false);
现在复选框和列表项一样可以点击。
【讨论】：