Atof Equivalent in C#

	int pos=0,p=0;
	double v1,expo,res;

	p=value.find("e+");
	
	if(value.find("e+")!=-1 ||value.find("e-")!=-1)
	{
		pos=value.find("e");
		if(atof(value.substr(0,pos).c_str()))
		{
		v1=StringToDouble(value.substr(0,pos));
		expo=StringToDouble(value.substr(pos+1,(value.length()-(pos+1))));
		res=pow(10,expo)*v1;
		return DoubleToString(res);


		}
	}

float myAtof(string myString)
{
    Predicate<char> testChar = c => c == '.' || 
                                    c == '-' || 
                                    c == '+' || 
                                    char.IsDigit(c);

    myString = new string(myString.Trim().TakeWhile(testChar).ToArray());

    if (myString.Length > 0)
    {
        float rvl;

        // accounts for bogus strings of valid chars, e.g. ".-":
        if (float.TryParse(myString, out rvl))
        {
            return rvl;
        }
    }

    return 0;
}