You have a string value in your C# program and want to find out if it a numeric value.
Double.TryParse method, which returns true if the input string is a number. Here we see how you can use Double.TryParse to test number strings.

public static bool IsNumeric(string s)
{
    double Result;
    return double.TryParse(s, out Result);  
}        
 
string value = "143";
if (IsNumeric(value)) 
{
  // do something
}
Check string is number,double.tr

Thanks