test123/FoldersListAdapter.java

/*这段代码定义了一个名为 FoldersListAdapter 的类，它是 CursorAdapter 的子类，
主要用于适配数据库查询结果（通过 Cursor 对象表示），并将数据绑定到列表项视图上。
此适配器特别适用于展示文件夹列表，每个文件夹项包含一个名称。*/


/*
 * Copyright (c) 2010-2011, The MiCode Open Source Community (www.micode.net)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package net.micode.notes.ui;  /*定义了代码所在的包名*/

import android.content.Context;
import android.database.Cursor;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CursorAdapter;
import android.widget.LinearLayout;
import android.widget.TextView;   /*导入了所需的类和接口*/

import net.micode.notes.R;
import net.micode.notes.data.Notes;
import net.micode.notes.data.Notes.NoteColumns;   /*导入了应用相关的资源和数据模型类*/


public class FoldersListAdapter extends CursorAdapter {  /*定义了一个名为 FoldersListAdapter 的公共类，继承自 CursorAdapter*/
    public static final String [] PROJECTION = {
        NoteColumns.ID,
        NoteColumns.SNIPPET
    };     /*定义了数据库查询的列名数组*/

    public static final int ID_COLUMN   = 0;
    public static final int NAME_COLUMN = 1;   /*定义了查询结果中每列的索引*/

    public FoldersListAdapter(Context context, Cursor c) {
        super(context, c);    /*构造函数，初始化父类 CursorAdapter*/
        // TODO Auto-generated constructor stub
    }

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent) {
        return new FolderListItem(context);
    }    /*覆盖 newView 方法，返回一个新的视图实例，这里返回的是一个 FolderListItem 实例*/

    @Override
    public void bindView(View view, Context context, Cursor cursor) {
        if (view instanceof FolderListItem) {
            String folderName = (cursor.getLong(ID_COLUMN) == Notes.ID_ROOT_FOLDER) ? context
                    .getString(R.string.menu_move_parent_folder) : cursor.getString(NAME_COLUMN);
            ((FolderListItem) view).bind(folderName);
        }
    }    /*覆盖 bindView 方法，将数据绑定到视图上。如果是根目录，则使用特定字符串，否则从 Cursor 中获取名称*/

    public String getFolderName(Context context, int position) {
        Cursor cursor = (Cursor) getItem(position);
        return (cursor.getLong(ID_COLUMN) == Notes.ID_ROOT_FOLDER) ? context
                .getString(R.string.menu_move_parent_folder) : cursor.getString(NAME_COLUMN);
    }      /*提供了一个方法用于根据位置获取文件夹名称*/

    private class FolderListItem extends LinearLayout {
        private TextView mName;

        public FolderListItem(Context context) {
            super(context);
            inflate(context, R.layout.folder_list_item, this);
            mName = (TextView) findViewById(R.id.tv_folder_name);
        }

        public void bind(String name) {
            mName.setText(name);
        }
    }   /*定义了一个内部类 FolderListItem，它是一个 LinearLayout 的子类，用于表示一个文件夹列表项，并提供了绑定数据的方法*/

}