我的ListView在一个片段中有一个BaseAdapter,它看起来像这样:
public class SelectionMucListAdapter extends BaseAdapter {
private LayoutInflater inflater = null;
Typeface titleFace;
ArrayList<UsersData> innerList = new ArrayList<UsersData>();
public SelectionMucListAdapter(ArrayList<UsersData> users) {
inflater = (LayoutInflater) mainActivity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
titleFace = Typeface.createFromAsset(mainActivity.getAssets(), "fonts/bradybun.ttf");
innerList = users;
}
@Override
public int getCount() {
return innerList.size();
}
@Override
public Object getItem(int position) {
return position;
}
@Override
public long getItemId(int id) {
return id;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder;
if (convertView == null) {
convertView = inflater.inflate(R.layout.muc_list_item, null);
viewHolder = new ViewHolder();
viewHolder.image = (ImageView)convertView.findViewById(R.id.item_image);
viewHolder.check = (CheckBox)convertView.findViewById(R.id.cb_choose_user);
viewHolder.title = (TextView)convertView.findViewById(R.id.item_text_1);
viewHolder.rating=(RatingBar)convertView.findViewById(R.id.item_text_2);
convertView.setTag(viewHolder);
}else{
viewHolder = (ViewHolder)convertView.getTag();
}
viewHolder.title.setTypeface(titleFace);
Bitmap avatar = innerList.get(position).getUserAvatar();//UsersManager.getInstance().getUsers().get(position).getUserAvatar();
if(avatar != null)
viewHolder.image.setImageBitmap(avatar);
viewHolder.title.setText(innerList.get(position).getUserName());
viewHolder.rating.setRating((float)Double.parseDouble(innerList.get(position).getRating()));
viewHolder.check.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton cb, boolean isChecked) {
if(cb.isChecked()) {// if this item is checked then add to list
Log.v("CheckBox", "pos: "+position+" checked");
if(!choices.contains(innerList.get(position))) {
choices.add(innerList.get(position));
}
} else {// if its unchecked then remove from list if exist
Log.v("CheckBox", "pos: "+position+" checked");
if(choices.contains(innerList.get(position))) {
choices.remove(innerList.get(position));
}
}
isChecked = cb.isChecked();
}
});
viewHolder.check.setTag(position);
return convertView;
}
}
static class ViewHolder{
ImageView image;
CheckBox check;
TextView title;
RatingBar rating;
}
class CheckState{
boolean isChecked;
UsersData usersData;
public UsersData getUsersData() {
return usersData;
}
public void setUsersData(UsersData usersData) {
this.usersData = usersData;
}
public boolean isChecked() {
return isChecked;
}
public void setChecked(boolean isChecked) {
this.isChecked = isChecked;
}
}
我有20个列表项,问题是,当我检查前两个项时,例如在索引[0]和[1]处,不知何故,当我向下滚动列表时,它也会自动检查索引[9]和[10]处的其他项。如果我检查了其他项目,就会出现同样的情况,每次我向下滚动列表时,它都会以相同的模式重复检查。
我真的不知道发生了什么,所以我想问这里是否有人能阻止这种混乱。非常感谢。
您的自定义适配器必须实现CompoundButton.OnCheckedChangeListener
。使用SparseBooleanArray.
然后
cb.setChecked(mCheckStates.get(position, false)); // cb is checkbox
cb.setOnCheckedChangeListener(this);
然后使用选中状态将文本设置为复选框
public boolean isChecked(int position) {
return mCheckStates.get(position, false);
}
public void setChecked(int position, boolean isChecked) {
mCheckStates.put(position, isChecked);
}
public void toggle(int position) {
setChecked(position, !isChecked(position));
}
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
mCheckStates.put((Integer) buttonView.getTag(), isChecked);
}
关于主题@的讨论
https://groups.google.com/forum/?fromgroups#!主题/安卓开发者/No0LrgJ6q2M
示例:
使用ViewHolder
。以下示例不使用视图固定器。
屏幕底部有一个按钮。选中复选框时,单击底部的按钮时,选中行的项目将显示在toast中。
使用以下内容并根据您的要求进行修改。
public class MainActivity extends Activity implements
AdapterView.OnItemClickListener {
int count;
private CheckBoxAdapter mCheckBoxAdapter;
String[] GENRES = new String[] {
"Action", "Adventure", "Animation", "Children", "Comedy",
"Documentary", "Drama",
"Foreign", "History", "Independent", "Romance", "Sci-Fi",
"Television", "Thriller"
};
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
final ListView listView = (ListView) findViewById(R.id.lv);
listView.setItemsCanFocus(false);
listView.setTextFilterEnabled(true);
listView.setOnItemClickListener(this);
mCheckBoxAdapter = new CheckBoxAdapter(this, GENRES);
listView.setAdapter(mCheckBoxAdapter);
Button b= (Button) findViewById(R.id.button1);
b.setOnClickListener(new OnClickListener()
{
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
StringBuilder result = new StringBuilder();
for(int i=0;i<mCheckBoxAdapter.mCheckStates.size();i++)
{
if(mCheckBoxAdapter.mCheckStates.get(i)==true)
{
result.append(GENRES[i]);
result.append("n");
}
}
Toast.makeText(MainActivity.this, result, 1000).show();
}
});
}
public void onItemClick(AdapterView parent, View view, int
position, long id) {
mCheckBoxAdapter.toggle(position);
}
class CheckBoxAdapter extends ArrayAdapter implements CompoundButton.OnCheckedChangeListener
{ private SparseBooleanArray mCheckStates;
LayoutInflater mInflater;
TextView tv1,tv;
CheckBox cb;
String[] gen;
CheckBoxAdapter(MainActivity context, String[] genres)
{
super(context,0,genres);
mCheckStates = new SparseBooleanArray(genres.length);
mInflater = (LayoutInflater)MainActivity.this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
gen= genres;
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return gen.length;
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return position;
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
View vi=convertView;
if(convertView==null)
vi = mInflater.inflate(R.layout.checkbox, null);
tv= (TextView) vi.findViewById(R.id.textView1);
cb = (CheckBox) vi.findViewById(R.id.checkBox1);
tv.setText("Name :"+ gen [position]);
cb.setTag(position);
cb.setChecked(mCheckStates.get(position, false));
cb.setOnCheckedChangeListener(this);
return vi;
}
public boolean isChecked(int position) {
return mCheckStates.get(position, false);
}
public void setChecked(int position, boolean isChecked) {
mCheckStates.put(position, isChecked);
}
public void toggle(int position) {
setChecked(position, !isChecked(position));
}
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
mCheckStates.put((Integer) buttonView.getTag(), isChecked);
}
}
}
我目前正在使用此处提供的解决方案:带复选框滚动问题的列表视图
它对我有效,我这样更改适配器类:
public class SelectionMucListAdapter extends ArrayAdapter<Model> {
private final FragmentActivity context;
Typeface titleFace;
ArrayList<Model> innerList
= new ArrayList<Model>();
boolean checkAll_flag = false;
boolean checkItem_flag = false;
public SelectionMucListAdapter(FragmentActivity context
, ArrayList<Model> users) {
super(context, R.layout.muc_list_item, users);
this.context = context;
titleFace = Typeface.createFromAsset
(mainActivity.getAssets(), "fonts/bradybun.ttf");
this.innerList = users;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
ViewHolder viewHolder = null;
if (convertView == null) {
LayoutInflater inflator = context.getLayoutInflater();
convertView = inflator.inflate(R.layout.muc_list_item, null);
viewHolder = new ViewHolder();
viewHolder.image = (ImageView) convertView.findViewById(R.id.item_image);
viewHolder.title = (TextView) convertView.findViewById(R.id.item_text_1);
viewHolder.title.setTypeface(titleFace);
viewHolder.rating= (RatingBar) convertView.findViewById(R.id.item_text_2);
viewHolder.check = (CheckBox) convertView.findViewById(R.id.cb_choose_user);
viewHolder.check.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
// TODO Auto-generated method stub
int getPosition = (Integer) buttonView.getTag(); // Here we get the position that we have set for the checkbox using setTag.
innerList.get(getPosition).setSelected(buttonView.isChecked()); // Set the value of checkbox to maintain its state.
users.get(innerList.get(getPosition).getTrueIndex()).setSelected(buttonView.isChecked());
}
});
convertView.setTag(viewHolder);
convertView.setTag(R.id.item_image, viewHolder.image);
convertView.setTag(R.id.item_text_1, viewHolder.title);
convertView.setTag(R.id.item_text_2, viewHolder.rating);
convertView.setTag(R.id.cb_choose_user, viewHolder.check);
} else {
viewHolder = (ViewHolder) convertView.getTag();
}
viewHolder.check.setTag(position); // This line is important.
viewHolder.title.setText(innerList.get(position).getData().getUserName());
viewHolder.rating.setRating((float)
Double.parseDouble(innerList.get(position).getData().getRating()));
viewHolder.check.setChecked(innerList.get(position).isSelected());
Bitmap avatar = innerList.get(position).getData().getUserAvatar();
if(avatar != null)
viewHolder.image.setImageBitmap(avatar);
return convertView;
}
class ViewHolder {
ImageView image;
CheckBox check;
TextView title;
RatingBar rating;
}
}
我使用两个数组列表来保存数据:第一个用于所有数据,第二个用于用户当前搜索的数据。因此,当用户键入关键字进行搜索时,检查状态会在第一个和第二个数组列表之间传递,从而产生持久性检查项,无论它们在哪个位置。
但感谢拉古南丹,你的回答是我达成更好解决方案的基石!
这里的技巧是使用一个size()=列表视图项数的布尔数组。目的是标记哪个项目被选中,哪个项目没有被选中。检查项目时,请根据其位置更新其状态。希望这能帮助你。:)
除了@Raghunadan答案外,Android在滚动时重新使用列表视图中的视图,这样当你滚动列表视图时,最后一个离开屏幕的视图是下一个从另一侧进入屏幕的视图,因此,如果1和2被选中,并且9和10将在滚动后被选中,这可能意味着屏幕上同时显示有8个项目,使得第九个项目的android系统使用了第一个项目的视图,因此它将被选中。
我认为这在我的xml中对你很有用,我正在使用textview和checkbox.use getView()方法,就像我实现的那样,并使用bean类在活动和适配器之间进行通信。
import java.util.ArrayList;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.ImageView;
import android.widget.TextView;
public class MyAdapter extends BaseAdapter{
Context context;
ArrayList list;
LayoutInflater inflator;
public MyAdapter(Context context,ArrayList list)
{
this.context=context;
this.list=list;
inflator=(LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
// TODO Auto-generated method stub
return list.size();
}
@Override
public Object getItem(int position) {
// TODO Auto-generated method stub
return list.get(position);
}
@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return 0;
}
public class ViewHolder
{
ImageView imageView;
TextView name;
TextView mob;
CheckBox check;
public ViewHolder(View v)
{
imageView=(ImageView) v.findViewById(R.id.imageView1);
name=(TextView) v.findViewById(R.id.textView1);
mob=(TextView) v.findViewById(R.id.textView2);
check=(CheckBox) v.findViewById(R.id.checkBox1);
}
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
View vi=convertView;
ViewHolder holder;
final Contacts contacts=(Contacts) list.get(position);
if(convertView==null)
{
vi=inflator.inflate(R.layout.contacts, null);
holder=new ViewHolder(vi);
vi.setTag(holder);
}
else
{
holder=(ViewHolder) vi.getTag();
}
holder.imageView.setImageBitmap(contacts.getImage());
holder.name.setText(contacts.getName());
holder.mob.setText(contacts.getNumber());
holder.check.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
contacts.setCheck(isChecked);
notifyDataSetChanged();
}
});
holder.check.setChecked(contacts.isCheck());
return vi;
}
}