MongoDBHelper

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using MongoDB;

public class MongoDBHelper : IDisposable
{
    private Mongo _mongo;
    private IMongoDatabase _db;
    private static readonly string connString = "Server=127.0.0.1";//默认的数据库链接
    private static readonly string dbName = "NewsDB";//默认的数据库
    public MongoDBHelper()
        : this(connString, dbName) //可以给定默认的链接字符串和名称
    {

    }
    /// <summary>
    /// 连接MongoDB
    /// </summary>
    /// <param name="dbName">数据库名称，服务器使用默认连接</param>
    public MongoDBHelper(string dbName)
    {
        _mongo = new Mongo(connString);
        if (!string.IsNullOrEmpty(dbName))
            _db = _mongo.GetDatabase(dbName);
        else
            throw new ArgumentNullException("DBName 为空．．．");
    }
    /// <summary>
    /// 连接MongoDB
    /// </summary>
    /// <param name="connString">连接字符串</param>
    /// <param name="dbName">数据库名称</param>
    public MongoDBHelper(string connString, string dbName)
    {
        if (!string.IsNullOrEmpty(connString))
            _mongo = new Mongo(connString);
        else
            throw new ArgumentNullException("connectionString为空．．．");
        _mongo.Connect();
        if (!string.IsNullOrEmpty(dbName))
            _db = _mongo.GetDatabase(dbName);
        else
            throw new ArgumentNullException("DBName 为空．．．");
    }

    /// <summary>
    /// 获取指定数据库的集合
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <returns></returns>
    public IMongoCollection<T> GetCollection<T>() where T : class
    {
        return _db.GetCollection<T>();
    }
    /// <summary>
    /// 获取指定数据库的集合
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="name"></param>
    /// <returns></returns>
    public IMongoCollection<T> GetCollection<T>(string name) where T : class
    {
        return _db.GetCollection<T>(name);
    }
    /// <summary>
    /// 根据指定的名称切换数据库
    /// </summary>
    /// <param name="dbName"></param>
    /// <returns></returns>
    public IMongoDatabase ChangeDB(string dbName)
    {
        if (!string.IsNullOrEmpty(dbName))
            _db = _mongo.GetDatabase(dbName);
        else
            throw new ArgumentNullException("DBName为空．．．");
        return _db;
    }



    #region IDisposable 成员

    public void Dispose()
    {
        if (_mongo != null)
        {
            _mongo.Dispose();
            _mongo = null;
        }
    }

    #endregion
}