如何用dot-Net核（C#）读取存储过程游标参数

我试图使用DotnetCore3.1和Npgsql从存储过程中获取数据。我几乎什么都试过了，但没有成功。我能帮上忙吗

PostgresSQL脚本

INSERT INTO DUMMY_TABLE VALUES(1, 'Albert');
INSERT INTO DUMMY_TABLE VALUES(2, 'Albert');
INSERT INTO DUMMY_TABLE VALUES(3, 'James');

CREATE PROCEDURE getId(IN _name text, INOUT p_refcur refcursor)
    AS
    $BODY$
    BEGIN
        OPEN p_refcur FOR
        select * from DUMMY_TABLE where name = _name;
    END;
    $BODY$
    LANGUAGE plpgsql;
    
call getId('Albert','cursor_name');
FETCH ALL IN "cursor_name";

Dotnet代码Snippit

 var cs = "Host=localhost;Username=postgres;Password=root;Database=temp";
using var con = new NpgsqlConnection(cs);
con.Open();

NpgsqlTransaction tr = (NpgsqlTransaction) con.BeginTransaction();
NpgsqlCommand cursCmd = new NpgsqlCommand("call getId(:param,:ref)", (NpgsqlConnection)con);
cursCmd.Transaction = tr;
NpgsqlParameter rf = new NpgsqlParameter("ref", NpgsqlTypes.NpgsqlDbType.Refcursor);
rf.Value = 'c';
rf.Direction = System.Data.ParameterDirection.InputOutput;

NpgsqlParameter param2 = new NpgsqlParameter("param", NpgsqlTypes.NpgsqlDbType.Text);
param2.Value = "Albert";
rf.Direction = System.Data.ParameterDirection.Input;
cursCmd.Parameters.Add(param2);
cursCmd.Parameters.Add(rf);
// return cursCmd.ExecuteScalar().ToString();

NpgsqlDataReader r = cursCmd.ExecuteReader();
    Console.WriteLine(r.Read());
var version = "default";
while (r.Read())
{
    ; // r.GetValue(0);
    version = r.GetValue(0).ToString();
        Console.WriteLine(r.GetColumnSchema());

}
r.NextResult();
while (r.Read())
{
    ;
        version = r.GetValue(0).ToString();
        Console.WriteLine(r);
}

// tr.Commit();
return version;

我从你那里借用了代码。我同意其他一些实现。谢谢