convert string to number C#

int x = Int32.Parse(TextBoxD1.Text);int x = 0;

Int32.TryParse(TextBoxD1.Text, out x);using System; namespace ConvertStringtoNumber{    public class Program    {        public static void Main(string[] args)        {            string s1="10";            string s2="20";            int num1=0,num2=0;            Int32.TryParse(s1, out num1);            Int32.TryParse(s2, out num2);             int add=num1+num2;            Console.WriteLine("Addition of 10 and 20 is {0}",add.ToString());         }    }}Int16.Parse("100"); // returns 100
Int16.Parse("(100)", NumberStyles.AllowParentheses); // returns -100

int.Parse("30,000", NumberStyles.AllowThousands, new CultureInfo("en-au"));// returns 30000
int.Parse("$ 10000", NumberStyles.AllowCurrencySymbol); //returns 100
int.Parse("-100", NumberStyles.AllowLeadingSign); // returns -100
int.Parse(" 100 ", NumberStyles.AllowLeadingWhite | NumberStyles.AllowTrailingWhite); // returns 100

Int64.Parse("2147483649"); // returns 2147483649