C# convert bit to boolean

DataReader.GetBoolean(x)

or

Convert.ToBoolean(DataRow[x])

Depending on how are you performing the SQL queries it may depend. For example if you have a data reader you could directly read a boolean value:

using (var conn = new SqlConnection(ConnectionString))
using (var cmd = conn.CreateCommand())
{
    conn.Open();
    cmd.CommandText = "SELECT isset_field FROM sometable";
    using (var reader = cmd.ExecuteReader())
    {
        while (reader.Read())
        {
            bool isSet = reader.GetBoolean(0);
        }
    }
}

How are you extracting the fields from the database?

The SqlDataReader class has a GetBoolean method which does the translation for you:

bool yourBoolean = reader.GetBoolean(reader.GetOrdinal("Your_Bit_Column"));