C# 写随机卡号和密码的方法

Random RA = new Random();
string CardNO; string PassNo = "";
string RStr = "1234567890ABCDEFGHJIJKLMNOPQRSTUVWXYZ";
private void button1_Click(object sender, EventArgs e)
{

for (int num = 1; num <= Convert.ToInt32(this.CardCount.Text); num++)
{
this.CardNO = "";
this.PassNo = "";
for (int num2 = 1; num2 <= 12; num2++)
{
int maxValue = this.RA.Next(35);
int startIndex = Convert.ToInt32(this.RA.Next(maxValue));
this.CardNO += this.RStr.Substring(startIndex, 1);
startIndex = Convert.ToInt32(this.RA.Next(maxValue));
this.PassNo += this.RStr.Substring(startIndex, 1);
}
Console.WriteLine($"{this.CardNO},    {this.PassNo}");
}
}