问题
I'm trying to convert this string to double
Convert.ToDouble("1.12");
and this is the output
System.FormatException was unhandled.
Should I do something like this?
public static double ConvertToDouble(string ParseVersion)
{
double NewestVersion;
try
{
NewestVersion = Convert.ToDouble(ParseVersion);
}
catch
{
ParseVersion = ParseVersion.Replace('.', ',');
NewestVersion = Convert.ToDouble(ParseVersion);
}
return NewestVersion;
}
ConvertToDouble("1.12");
Or is there an easier solution?
回答1:
double.Parse
will use the current culture by default. It sounds like you want the invariant culture:
double d = double.Parse("1.12", CultureInfo.InvariantCulture);
EDIT: Just to be clear, obviously you shouldn't use this if you're trying to parse text entered by a user in a different culture. This is for use when you've received data in the invariant culture (as most machine-to-machine data text-based formats are) and want to enforce that when parsing.
回答2:
You don't have to replace .
to ,
.. however a better way is to use the .net TryParse
method like:
double d;
if (double.TryParse("your string data", out d)
{
Console.WriteLine(d);
}
Edit: Also note that by replacing .
by ,
you are getting a wrong results, for instance 1.12
:
double d = double.Parse(1.12);//d will equals to 1.12
double d = double.Parse(1,12);//d will equals to 112.0
回答3:
Convert.ToDouble uses Double.Parse internally. If you are unsure of the culture context, you should use an overload of Double.Parse precising the culture:
double d = double.Parse("1.12", CultureInfo.InvariantCulture);
回答4:
Keep in mind, this problem can depend on where the input string comes from. If it is read from a database as an object, you might solve your problem by keeping it as an object and using Convert.ToDouble() as follows:
public double Double_fromObject(object obj)
{
double dNum = 0.0;
if (obj.ToString() != string.Empty) // the Convert fails when ""
{
try
{
dNum = Convert.ToDouble(obj);
}
catch (SystemException sex)
{
// this class's error string
LastError = sex.Message;
}
}
return (dNum);
}
来源:https://stackoverflow.com/questions/6800418/c-sharp-convert-todouble-format-exception-error