从XML文件中获取部分连接字符串(Taking part of connection string from XML file)

 我试图根据包含服务器IP地址的XML文件构建一个连接到firebird数据库的连接字符串。 
 
public class globals
{
    static string _serv;
    public static string serv
    {
        get
        {
            return _serv;
        }
        set
        {
            _serv=value;
        }
    }
    public static XmlDocument xmld = new XmlDocument();

    public static void serv_check()
    {
        xmld.Load("ustawienia.xml");
        globals._serv = xmld.GetElementsByTagName("ip").Item(0).InnerText;
        if (globals._serv.Length<=0)
        {
            MessageBox.Show("Nie zdefiniowano servera");
            Server_Deff sdf = new Server_Deff();
            sdf.ShowDialog();               
        }
    }

    static string db_user = "SYSDBA";
    static string db_pass = "masterkey";

    public static string cstr=
                "User=" + globals.db_user + ";" +
                "Password=" + globals.db_pass + ";" +
                "Database=db_kanc;" +
                "DataSource=" + globals.serv +
                "Port=3050;" +
                "Dialect=3;" +
                "Charset=NONE;" +
                "Role=appka;" +
                "Connection lifetime=15;" +
                "Pooling=true;" +
                "MinPoolSize=0;" +
                "MaxPoolSize=50;" +
                "Packet Size=8192;" +
                "ServerType=0";

    public static FbConnection conn = new FbConnection(globals.cstr);
    public static FbTransaction transaction;


    public static void openConnection() // Open database Connection
    {
    conn.Open();
    transaction = conn.BeginTransaction();
}
 
 由于某些原因，既没有在XML文件中定义IP地址也没有在它不是变量serv时，似乎是null。 我可以通过消息框获取值，但不能在连接字符串中获取正确的数据源。 
 
 在尝试连接到db时，我收到如下错误： 
 
FirebirdSql.Data.FirebirdClient.FbException: Unable to complete network request to host "Port=3050". ---> FirebirdSql.Data.Common.IscException: Unable to complete network request to host "Port=3050".
   w FirebirdSql.Data.Client.Managed.Version10.GdsConnection.Connect()
   w FirebirdSql.Data.FirebirdClient.ClientFactory.CreateManagedDatabase(FbConnectionString options)
   w FirebirdSql.Data.FirebirdClient.ClientFactory.CreateDatabase(FbConnectionString options)
   w FirebirdSql.Data.FirebirdClient.FbConnectionInternal.Connect()
 
 有任何想法吗？ 

I've tried to build a connection string to a firebird db based on some XML file containing server IP address.
 
public class globals
{
    static string _serv;
    public static string serv
    {
        get
        {
            return _serv;
        }
        set
        {
            _serv=value;
        }
    }
    public static XmlDocument xmld = new XmlDocument();

    public static void serv_check()
    {
        xmld.Load("ustawienia.xml");
        globals._serv = xmld.GetElementsByTagName("ip").Item(0).InnerText;
        if (globals._serv.Length<=0)
        {
            MessageBox.Show("Nie zdefiniowano servera");
            Server_Deff sdf = new Server_Deff();
            sdf.ShowDialog();               
        }
    }

    static string db_user = "SYSDBA";
    static string db_pass = "masterkey";

    public static string cstr=
                "User=" + globals.db_user + ";" +
                "Password=" + globals.db_pass + ";" +
                "Database=db_kanc;" +
                "DataSource=" + globals.serv +
                "Port=3050;" +
                "Dialect=3;" +
                "Charset=NONE;" +
                "Role=appka;" +
                "Connection lifetime=15;" +
                "Pooling=true;" +
                "MinPoolSize=0;" +
                "MaxPoolSize=50;" +
                "Packet Size=8192;" +
                "ServerType=0";

    public static FbConnection conn = new FbConnection(globals.cstr);
    public static FbTransaction transaction;


    public static void openConnection() // Open database Connection
    {
    conn.Open();
    transaction = conn.BeginTransaction();
}
 
For some reasons neither when the IP address is defined in XML file nor when it's not variable serv seems to be null. I can get the value through message box but not as a proper Datasource in connection string.
 
While trying to connect to db I'm getting error like this:
 
FirebirdSql.Data.FirebirdClient.FbException: Unable to complete network request to host "Port=3050". ---> FirebirdSql.Data.Common.IscException: Unable to complete network request to host "Port=3050".
   w FirebirdSql.Data.Client.Managed.Version10.GdsConnection.Connect()
   w FirebirdSql.Data.FirebirdClient.ClientFactory.CreateManagedDatabase(FbConnectionString options)
   w FirebirdSql.Data.FirebirdClient.ClientFactory.CreateDatabase(FbConnectionString options)
   w FirebirdSql.Data.FirebirdClient.FbConnectionInternal.Connect()
 
Any ideas?

原文：https://stackoverflow.com/questions/27893109