string s1 = "1.0"
float f1 = float.Parse(s1);
// Change the delimiter - (The default delimiter is based on your current CultureInfo)
var ci = (CultureInfo)CultureInfo.CurrentCulture.Clone();
ci.NumberFormat.NumberDecimalSeparator = ",";
string s2 = "1,1";
float f2 = float.Parse(s2, ci);