封装一个MongoDB的 asp.net 链接类

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


/// <summary>
/// 对Mongo和MongoDatabase的包装类
/// </summary>
public class MyMongoDb : IDisposable
{
    private Mongo _mongo;
    private IMongoDatabase _db;
    private static string connectionString = "Server=127.0.0.1;mydb";
    private static readonly string _connectionString = connectionString.Split(';')[0];// "Server=127.0.0.1";
    private static readonly string _dbName = connectionString.Split(';')[1];



    public MyMongoDb()
        : this(_connectionString, _dbName)
    {
    }

    public MyMongoDb(string dbName)
        : this(_connectionString, dbName)
    {
    }

    /// <summary>
    /// 构造函数。根据指定连接字符串和数据库名
    /// </summary>
    /// <param name="connectionString">连接字符串</param>
    /// <param name="dbName">数据库名，可为空，但必须在任何操作数据库之前要调用UseDb()方法</param>
    public MyMongoDb(string connectionString, string dbName)
    {
        if( string.IsNullOrEmpty(connectionString) )
            throw new ArgumentNullException("connectionString");

        _mongo = new Mongo(connectionString);

        // 立即连接 MongoDB
        _mongo.Connect();

        if( string.IsNullOrEmpty(dbName) == false )
            _db = _mongo.GetDatabase(dbName);
    }

    /// <summary>
    /// 切换到指定的数据库
    /// </summary>
    /// <param name="dbName"></param>
    /// <returns></returns>
    public IMongoDatabase UseDb(string dbName)
    {
        if( string.IsNullOrEmpty(dbName) )
            throw new ArgumentNullException("dbName");

        _db = _mongo.GetDatabase(dbName);
        return _db;
    }

    /// <summary>
    /// 获取当前连接的数据库
    /// </summary>
    public IMongoDatabase CurrentDb
    {
        get
        {
            if( _db == null )
                throw new Exception("当前连接没有指定任何数据库。请在构造函数中指定数据库名或者调用UseDb()方法切换数据库。");

            return _db;
        }
    }

    /// <summary>
    /// 获取当前连接数据库的指定集合【依据类型】
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <returns></returns>
    public IMongoCollection<T> GetCollection<T>() where T : class
    {
        return this.CurrentDb.GetCollection<T>();
    }

    /// <summary>
    /// 获取当前连接数据库的指定集合【根据指定名称】
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="name">集合名称</param>
    /// <returns></returns>
    public IMongoCollection<T> GetCollection<T>(string name) where T : class
    {
        return this.CurrentDb.GetCollection<T>(name);
    }

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

使用链接类

public void Insert(USER user)
{
    using (MyMongoDb mdb = new MyMongoDb())
    {
        var collection = mdb.GetCollection<USER>();

        collection.Insert(user);
    }