How To Generate Random Charecters Using C#, I Tried The Code Below But It Doesnt Work

private string GetUniqueKey()
{
int maxSize = 8 ;
int minSize = 5 ;
char[] chars = new char[62];
string a;
a = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890";
chars = a.ToCharArray();
int size = maxSize ;
byte[] data = new byte[1];
RNGCryptoServiceProvider crypto = new RNGCryptoServiceProvider();
crypto.GetNonZeroBytes(data) ;
size = maxSize ;
data = new byte[size];
crypto.GetNonZeroBytes(data);
StringBuilder result = new StringBuilder(size) ;
foreach(byte b in data )
{ result.Append(chars[__b % (chars.Length - )>); }
return result.ToString();
}