Connect to MongoDB

https://docs.mongodb.com/getting-started/csharp/client/

MongoDB C# Driver is the officially supported C# driver for MongoDB.

Procedure

Download the MongoDB C# Driver.

To download the C# driver, follow the instructions found on MongoDB C#/.NET Driver page.

Add Reference to C# Driver DLLs.

Add to your project references to the following DLLs:

1. MongoDB.Bson.dll
2. MongoDB.Driver.dll
3. MongoDB.Driver.Core.dll

Connect to MongoDB.

Use MongoClient to connect to a running mongod instance.

Add the following using statements in your C# program.

using MongoDB.Bson;
using MongoDB.Driver;

Include the following code in your program to create a client connection to a running mongod instance and use the test database.

protected static IMongoClient _client;
protected static IMongoDatabase _database;

_client = new MongoClient();
_database = _client.GetDatabase("test");

To specify a different host and port for the mongod instance, see the MongoClient API page.

ps：

上面的第一步和第二步，可以直接通过NuGet来添加