EF Core 3.0 手动设置连接字符串

Question

我正在开发一个带有.NET Core和EF Core的控制台应用程序（两者都是v3.0）;我需要使用从另一个类生成的字符串启动我的DbContext。DbContext 文件public Arta_LuniaDBContext() { }public Arta_LuniaDBContext(DbContextOptions<Arta_LuniaDBContext> options) : base(options) { }protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder){   optionsBuilder.UseSqlServer(DataServices.ConnectionString);}数据服务类public static string ConnectionString { get { return GetConnectionData(); } }private static string GetConnectionData(){   /// Sets the Server name, Database, UserId and Password.   string Server, Database, UserId, Password;   /// Sets the separator.   string Separator = ";";   /// Connection string [internal].   string ArtaConn = null;   /// Loads Settings.xml   XmlDocument xDoc = new XmlDocument();   xDoc.Load("Settings.xml");   /// Gets the XmlNode: DataSource   XmlNodeList xSource = xDoc.GetElementsByTagName("DataSource");   for (int i = 0; i < xSource.Count; i++)   {      /// Sets the Server name.      Server = "Server=" + xSource[i].Attributes["Server"].Value + Separator;      /// Sets the Database.      Database = "Database=" + xSource[i].Attributes["Database"].Value + Separator;      /// Sets the User id.   UserId = "User id=" + xSource[i].Attributes["UserId"].Value + Separator;      /// Sets the Password.      Password = "Password=" + xSource[i].Attributes["Password"].Value + Separator;      /// Builds the connection string.      ArtaConn = Server + Database + UserId + Password;      Colorful.Console.WriteLine(ArtaConn, System.Drawing.Color.Yellow);      // I'm using this line to test the output.   }   /// Returns~   return ArtaConn;}

Answer 1

使用正确的工具完成工作 - SqlConnectionStringBuilder 类

生成器将转义反斜杠并为 Sql Server 连接构建正确的连接字符串。

var builder = new SqlConnectionStringBuilder

{

    DataSource = @"IP_ADDRESS\INSTANCE",

    InitialCatalog = "DbName",

    UserID = "MyUserId",

    Password = "MyPassword"

};

var connectionString = builder.ConnectionString;

// Use connection string

optionsBuilder.UseSqlServer(connectionString );

因此，您的方法可以如下所示：

private SqlConnectionStringBuilder BuilderFromElement(XElement source)

{

    return new SqlConnectionStringBuilder

    {

        DataSource = source.Attribute("Server")?.Value,

        InitialCatalog = source.Attribute("Database")?.Value,

        UserID = source.Attribute("UserID")?.Value,

        Password = source.Attribute("Password")?.Value

    };

}

private string GetConnectionString()

{

    var settings = XDocument.Load("Settings.xml");

    var allConnectionStrings = 

        settings.Descendants("DataSource")

                .Select(BuilderFromElement)

                .Select(builder => builder.ConnectionString)

                

    return allConnectionStrings.FirstOrDefault();

}

Answer 2

查看 xml 文件中反斜杠的用法。

在某些上下文中，可以是转义的 \，作为文字，它是 2 个斜杠。\\

此代码说明了这一点：这些字符串不相等。

        String s= "Server=IP\\INSTANCE_NAME;Database=db;User id=User ;Password=pwd;";

    String s2= @"Server=IP\\INSTANCE_NAME;Database=db;User id=User ;Password=pwd;";

    Console.WriteLine(s2== s);

如果您尝试使用localhost进行此操作，它是否按照您的期望方式工作？如果是这样：罪魁祸首是 .

您还可以查看这是否有效。

optionsBuilder.UseSqlServer(@"Server=Server=IP\\INSTANCE_NAME;Database=DB;User id=User ;Password=pwd;");

希望这有帮助！