Advice on how to use c # driven by SSL connection Mongo-CodePudding

The building Lord white without SSL before, most recently with the huawei cloud, their database default SSL, gave it to a ca. CRT certificate, now want to use c # mongo Driver (2.7.0) to connect, see along while documents, has written the following code, but the connection is not on, for a great god how should change? Mongo version 3.4

 
Var cert=new X509Certificate2 (file.readallbytes (" ca. CRT) ", "password");//the password is the database password, so use? 
Var Settings=new MongoClientSettings 
{
Server=new MongoServerAddress (" X.X.X.X ", 8635), 
The Credential=MongoCredential. CreateCredential (" mydatabase ", "rwuser", "password"), 
SslSettings=new SslSettings 
{
ClientCertificates=new [] {cert}, 
}, 
UseSsl=true 
}; 
MongoClient client=new MongoClient (Settings); 
IMongoDatabase db=client. GetDatabase (" mydatabase "); 
Try 
{
Var collection=db. GetCollection (" Admin "); 
Var doc=collection. The Find (s=& gt; S.U sername=="admin"). FirstOrDefault ();//the program card in this step is not gone 
Console. WriteLine (doc. Username); 
} 
The catch (Exception ex) 
{
Console.WriteLine(ex.Message); 
}