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我正在尝试实现一段我发现的代码来存储 a 的状态，CheckBox但ListView它没有工作。有谁知道为什么我的适配器中的代码不起作用？

package kevin.erica.box;

import java.util.ArrayList;

import kevin.erica.box.R;

import android.R.color;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.CheckBox;
import android.widget.ImageView;
import android.widget.TextView;

public class MobileArrayAdapter extends ArrayAdapter<String> {
    private final Context context;
    private final String[] values;
    private ArrayList<Boolean> itemChecked = new ArrayList<Boolean>();

    public MobileArrayAdapter(Context context, String[] values) {
        super(context, R.layout.list_adapter, values);
        this.context = context;
        this.values = values;

        for (int i = 0; i < this.getCount(); i++) {
            itemChecked.add(i, false); // initializes all items value with false
        }
    }


    @Override
    public View getView(final int position, View covertView, ViewGroup parent) {
        LayoutInflater inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
            View rowView = inflater.inflate(R.layout.list_adapter, parent, false);
            CheckBox textView = (CheckBox) rowView.findViewById(R.id.checkBox1);
            textView.setTextColor(0xFFFFFFFF);
            textView.setText(values[position]);
            //Store state attempt
            final CheckBox cBox = (CheckBox) rowView.findViewById(R.id.checkBox1); // your
            // CheckBox
            cBox.setOnClickListener(new OnClickListener() {

                public void onClick(View v) {

                CheckBox cb = (CheckBox) v.findViewById(R.id.checkBox1);

                if (cb.isChecked()) {
                    itemChecked.set(position, true);
                    // do some operations here
                } else if (!cb.isChecked()) {
                    itemChecked.set(position, false);
                    // do some operations here
                }
            }
        });
        cBox.setChecked(itemChecked.get(position)); // this will Check or Uncheck the
        // CheckBox in ListView
        // according to their original
        // position and CheckBox never
        // loss his State when you
        // Scroll the List Items.
        return rowView;
    }
}
4

2 回答 2

2

您的问题没有说明应用程序关闭后存储数据的任何内容。要存储检查CheckBoxes，您可以使用数据库或简单文件。CheckBoxBellow 是将状态存储在数据库中的示例：

public class SimplePlay extends ListActivity {

    private String[] soundnames;
    private Helper mHelper = new Helper(this, "position_status.db", null, 1);
    private SQLiteDatabase statusDb;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // this is to simulate data
        soundnames = new String[40];
        for (int i = 0; i < 40; i++) {
            soundnames[i] = "Sound " + i;
        }
        // Retrieve the list of position that are checked(if any) from the
        // database
        statusDb = mHelper.getWritableDatabase();
        Cursor statusCursor = statusDb.rawQuery("SELECT * FROM status", null);
        int[] savedStatus = null;
        if ((statusCursor != null) & (statusCursor.moveToFirst())) {
            savedStatus = new int[statusCursor.getCount()];
            int i = 0;
            do {
                savedStatus[i] = statusCursor.getInt(0);
                i++;
            } while (statusCursor.moveToNext());
        }
        // if the cursor is null or empty we just pass the null savedStatus to
        // the adapter constructor and let it handle(setting all the CheckBoxes
        // to unchecked)
        setListAdapter(new MobileArrayAdapter(this, soundnames, savedStatus));
    }

    public class MobileArrayAdapter extends ArrayAdapter<String> {
        private final Context context;
        private final String[] values;
        private ArrayList<Boolean> itemChecked = new ArrayList<Boolean>();

        public MobileArrayAdapter(Context context, String[] values,
                int[] oldStatus) {
            super(context, R.layout.adapters_simpleplay_row, values);
            this.context = context;
            this.values = values;

            // make every CheckBox unchecked and then loop through oldStatus(if
            // not null)
            for (int i = 0; i < this.getCount(); i++) {
                itemChecked.add(i, false);
            }
            if (oldStatus != null) {
                for (int j = 0; j < oldStatus.length; j++) {
                    itemChecked.set(oldStatus[j], true);
                }
            }
        }

        @Override
        public View getView(final int position, View convertView,
                ViewGroup parent) {
            View rowView = convertView;
            if (rowView == null) {
                LayoutInflater inflater = (LayoutInflater) context
                        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                rowView = inflater.inflate(R.layout.adapters_simpleplay_row,
                        parent, false);
            }
            CheckBox cBox = (CheckBox) rowView.findViewById(R.id.checkBox1);
            cBox.setTextColor(0xFFFFFFFF);
            cBox.setText(values[position]);
            cBox.setTag(new Integer(position));
            cBox.setOnCheckedChangeListener(new OnCheckedChangeListener() {

                @Override
                public void onCheckedChanged(CompoundButton buttonView,
                        boolean isChecked) {
                    int realPosition = (Integer) buttonView.getTag();
                    if (isChecked) {
                        itemChecked.set(realPosition, true);
                        // update the database to store the new checked item:
                        ContentValues cv = new ContentValues();
                        cv.put("list_position", realPosition);
                        statusDb.insert("status", null, cv);
                    } else {
                        itemChecked.set(realPosition, false);
                        // delete this position from the database because it was
                        // unchecked
                        statusDb.delete("status", "list_position = "
                                + realPosition, null);
                    }
                }
            });
            cBox.setChecked(itemChecked.get(position));
            return rowView;
        }
    }

    //for working with the database
    private class Helper extends SQLiteOpenHelper {

        public Helper(Context context, String name, CursorFactory factory,
                int version) {
            super(context, name, factory, version);
        }

        @Override
        public void onCreate(SQLiteDatabase db) {
            // the list_position will hold the position from the list that are
            // currently checked
            String sql = "CREATE TABLE status (list_position INTEGER);";
            db.execSQL(sql);
        }

        @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            // Just for interface
        }

    }

}

经过快速测试，代码可以工作。这只是一个例子。

于 2012-04-23T12:40:53.567 回答
0

您可以做一件事，获取相同大小的布尔数组并存储它是否被单击

您还可以使用另一个类来存储检查状态...

这是多个联系人选择的示例，这肯定对您有所帮助.....

多选联系人

编辑：

例子

public class simple List extends ListActivity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setListAdapter(new ArrayAdapter<String>(this,
            android.R.layout.simple_list_item_multiple_choice, GENRES));

    final ListView listView = getListView();

    listView.setItemsCanFocus(false);
    listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
}

private static final String[] GENRES = new String[] { "india", "england", "London", "New york", "New jercy", "LA", "Pakistan", "srilanka", "bangladesh", "chin", "Australia", "Japan" };}
于 2012-04-23T12:00:02.337 回答