如何在包含列表视图的活动中访问使用适配器显示的复选框

Question

我正在开发以下屏幕：

通过使用Base Adapter填充listview来显示好友列表。

适配器

  public class Adapter_Friends_Group extends BaseAdapter {
    private Context context;
    private List<Bean_Friends> listBeanFriends;
    private LayoutInflater inflater;
    private ApiConfiguration apiConfiguration;

    public Adapter_Friends_Group(Context context, List<Bean_Friends> listBeanFriends) {
        this.context = context;
        this.listBeanFriends = listBeanFriends;
    }

    @Override
    public int getCount() {
        return listBeanFriends.size();
    }

    @Override
    public Object getItem(int i) {
        return listBeanFriends.get(i);
    }

    @Override
    public long getItemId(int i) {
        return i;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {
        if (inflater == null) {
            inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        }
        if (view == null) {
            view = inflater.inflate(R.layout.feed_item_friends, null);
        }

        //finding different views
        ImageView pic = (ImageView) view.findViewById(R.id.friendsImage);
        TextView txtName = (TextView) view.findViewById(R.id.nameFriends);
        CheckBox chkFriends = (CheckBox) view.findViewById(R.id.chkFriends);

        final Bean_Friends bean_friends = listBeanFriends.get(i);
        String name = bean_friends.getName();
        String url = bean_friends.getUrl();
        String extension = bean_friends.getExtension();
        apiConfiguration = new ApiConfiguration();
        String api = apiConfiguration.getApi();
        String absolute_url = api + "/" + url + "." + extension;

        //loading image into ImageView                                                                                                                                            iew
        Picasso.with(context).load(absolute_url).error(R.drawable.default_avatar).into(pic);

        //Setting name in the textview
        txtName.setText(name);

        chkFriends.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean isChecked) {
                Log.e("Checkboxxxxxxxxxx", "Clicked");
                if (isChecked) {
                    bean_friends.setFriendSelected("true");
                    Log.e("Checkbox", "Checked");
                } else {
                    bean_friends.setFriendSelected("false");
                    Log.e("Checkbox", "UnChecked");
                }
                listBeanFriends.add(bean_friends);
            }
        });
        return view;
    }
}

单击复选框时，我将在Bean中将字符串值保存为true。

豆

public class Bean_Friends {
    private String name, url, extension, friendsID;
    private String friendSelected;

    public String getName() {
        return name;
    }

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

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public String getExtension() {
        return extension;
    }

    public void setExtension(String extension) {
        this.extension = extension;
    }

    public String getFriendsID() {
        return friendsID;
    }

    public void setFriendsID(String friendsID) {
        this.friendsID = friendsID;
    }

    public String getFriendSelected() {
        return friendSelected;
    }

    public void setFriendSelected(String friendSelected) {
        this.friendSelected = friendSelected;
    }
}

现在在包含列表视图的活动中，在“想要访问顶部工具栏上单击单个勾选项时勾选了复选框的朋友的ID。”

点击单一刻度时使用以下方法：

public void createNewGroup() {
    Toast.makeText(NewGroupActivity.this, "clicked", Toast.LENGTH_SHORT).show();
    listBeanFriends = new ArrayList<>();
    for (int i = 0; i < listBeanFriends.size(); i++) {
        Log.e("Loop Working", "-------------");
        Bean_Friends bean_friends = listBeanFriends.get(i);
        String friendSelected = bean_friends.getFriendSelected();
        String friendID = bean_friends.getFriendsID();
        Log.e("FriendID", friendID);
        if (friendSelected.equals("true")) {
            Toast.makeText(NewGroupActivity.this, friendID, Toast.LENGTH_SHORT).show();
        } else {
            // Toast.makeText(NewGroupActivity.this,"true",Toast.LENGTH_SHORT).show();
        }
    }
}

但这对我有用。我想访问点击单勾选中复选框的朋友的ID。请帮我解决问题。

更新代码：

我做了以下更改。现在它正在为我工​​作。

适配器

    public class Adapter_Friends_Group extends BaseAdapter {
    private Context context;
    public List<Bean_Friends> listBeanFriends;
    private LayoutInflater inflater;
    private ApiConfiguration apiConfiguration;
    private Bean_Friends bean_friends;


    public Adapter_Friends_Group(Context context, List<Bean_Friends> listBeanFriends) {
        this.context = context;
        this.listBeanFriends = listBeanFriends;
    }

    private class ViewHolder {
        ImageView imageView;
        TextView txtName;
        CheckBox chkFriend;
    }

    @Override
    public int getCount() {
        return listBeanFriends.size();
    }

    @Override
    public Object getItem(int i) {
        return listBeanFriends.get(i);
    }

    @Override
    public long getItemId(int i) {
        return i;
    }

    @Override
    public View getView(int i, View view, ViewGroup viewGroup) {

        ViewHolder viewHolder = null;
        if (inflater == null) {
            inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        }
        if (view == null) {
            view = inflater.inflate(R.layout.feed_item_friends, null);
            viewHolder = new ViewHolder();
            viewHolder.imageView = (ImageView) view.findViewById(R.id.friendsImage);
            viewHolder.txtName = (TextView) view.findViewById(R.id.nameFriends);
            viewHolder.chkFriend = (CheckBox) view.findViewById(R.id.chkFriends);
            view.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) view.getTag();
        }

        bean_friends = listBeanFriends.get(i);
        String name = bean_friends.getName();
        String url = bean_friends.getUrl();
        String extension = bean_friends.getExtension();
        apiConfiguration = new ApiConfiguration();
        String api = apiConfiguration.getApi();
        String absolute_url = api + "/" + url + "." + extension;

        //loading image into ImageView                                                                                                                                            iew
        Picasso.with(context).load(absolute_url).error(R.drawable.default_avatar).into(viewHolder.imageView);
        //Setting name in the textview
        viewHolder.txtName.setText(name);
        //Setting boolean isSelected if the Checkbox is checked
        viewHolder.chkFriend.setChecked(bean_friends.isSelected());
        viewHolder.chkFriend.setTag(bean_friends);


        viewHolder.chkFriend.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                CheckBox cb = (CheckBox) view;
                Bean_Friends bean_friends = (Bean_Friends) cb.getTag();
                Toast.makeText(context, "Clicked on Checkbox: " + bean_friends.getName() + " is " + cb.isChecked(), Toast.LENGTH_LONG).show();
                bean_friends.setIsSelected(cb.isChecked());
            }
        });
        return view;
    }
}

豆

  public class Bean_Friends {
    private String name, url, extension, friendsID;
    boolean isSelected;

    public String getName() {
        return name;
    }

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

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public String getExtension() {
        return extension;
    }

    public void setExtension(String extension) {
        this.extension = extension;
    }

    public String getFriendsID() {
        return friendsID;
    }

    public void setFriendsID(String friendsID) {
        this.friendsID = friendsID;
    }

    public boolean isSelected() {
        return isSelected;
    }

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

活动内的方法

 public void createNewGroup() {
    StringBuffer responseText = new StringBuffer();
    listBeanFriends = adapter_friends_group.listBeanFriends;
    //  Log.e("Size of adapter_friends", String.valueOf(adapter_friends_group.listBeanFriends.size()));
    Log.e("Size of listbeanFriends", String.valueOf(listBeanFriends.size()));
    for (int i = 0; i < listBeanFriends.size(); i++) {
        Log.e("Loop Working", String.valueOf(i));
        Bean_Friends bean_friends = listBeanFriends.get(i);
        String friendID = bean_friends.getFriendsID();
        String friendName = bean_friends.getName();
        Log.e("FriendsName", friendName);
        Log.e("FriendID", friendID);
        Log.e("FriendSelected", String.valueOf(bean_friends.isSelected()));
        if (bean_friends.isSelected()) {
            responseText.append("\n" + bean_friends.getName() + "  " + bean_friends.getFriendsID());
        }
    }
    Toast.makeText(NewGroupActivity.this, responseText, Toast.LENGTH_SHORT).show();
}

Answer 1

尝试替换此行

listBeanFriends = new ArrayList<>();

使用：

List<Bean_Friends> listBeanFriends = new ArrayList<>();
    listBeanFriends = adapter.listBeanFriends;

Answer 2

我认为此链接可以帮助您：

http://www.mysamplecode.com/2012/07/android-listview-checkbox-example.html