连接到Firebird 3的C#程序中的“远程接口拒绝连接”

从Firebird 2.5迁移到3.0后,当我尝试使用C#程序测试数据库的连接时,会出现“远程接口拒绝连接”错误。

这是测试连接的代码,我在尝试连接firebird 2.5数据库时使用了这段代码。

txtPassword.Properties.UseSystemPasswordChar = true;
txtHostname.Text = Properties.Settings.Default.server;
txtUsername.Text = Properties.Settings.Default.user;
txtPassword.Text = Properties.Settings.Default.pass;
txtDBPath.Text = Properties.Settings.Default.dbpath;

void Testdbconn()
{
    try
    {
        var testInMemUnicode =
            String.Format("DataSource={0};Database={1};User ID={2};Password={3}; Charset=NONE;",
                          txtHostname.Text,
                          txtHostname.Text + ":" + txtDBPath.Text.Trim(),
                          txtUsername.Text,
                          txtPassword.Text);
        var testConnParam = new FbConnection(testInMemUnicode);
        testConnParam.Open();
        XtraMessageBox.Show(@"Connection to the server is successful.", @"Data Server Test",
                            MessageBoxButtons.OK,
                            MessageBoxIcon.Information);

    }
    catch (Exception errorCode)
    {
        XtraMessageBox.Show(@"Error in connection: " + errorCode.Message,
                            @"Server Error",
                            MessageBoxButtons.OK,
                            MessageBoxIcon.Exclamation);
    }
}

class ClsConnection
{
    public static string FirebirdSQL = String.Format(
        "DataSource={0}; Database={1}; User ID={2}; Password={3}; Charset=NONE; Port=3050; Dialect=3;" +
        "Connection lifetime=15; Pooling=true; MinPoolSize=0; MaxPoolSize=2000000; Packet Size=8192; ServerType=0",
        Properties.Settings.Default.server, Properties.Settings.Default.db + ":" + Properties.Settings.Default.dbpath,
        Properties.Settings.Default.user, Properties.Settings.Default.pass);

    private static readonly string FirebirdService = FirebirdSQL;

    /// <summary>
    /// 
    /// </summary>
    public static FbConnection Firebird = new FbConnection(FirebirdService);

    /// <summary>
    /// 
    /// </summary>
    public void Openconnection()
    {
        if (Firebird.State == System.Data.ConnectionState.Open)
        {
            Firebird.Close();
        }

        Firebird.Open();
    }

    /// <summary>
    /// 
    /// </summary>
    public void Closeconnection()
    {
        Firebird.Close();
    }
}