How can I read string value and store it in a array using data reader
string[] result = null;
while (reader.Read())
{
    result = Convert.ToString[](reader["RoleID"]);
}
reader.Close();

var results = new List<string>();
while (reader.Read())
{
    results.Add(reader["RoleID"].ToString());
}

// results now holds all of the RoleID values in the reader

string check = "something";
if (results.Any(item => item.Equals(check)))
{
    // results contains the value in check
}

// or use all items that equal check
foreach (var item in results.Where(obj => obj.Equals(check))
{
    // do something with each item that equals check
}

var result= new ArrayList();
while (reader.Read())
        {
            result.Add(Convert.ToString[](reader["RoleID"]));
        }reader.Close();

var results = new List<string>();
while( reader.Read() ){
    results.Add(reader["RoleID"].ToString());
}

foreach(var result in results) {
    if(result == "check") {
        // do something
    }
}