C# Is there a built-in function to convert a formatted String back to a Number?

问题

How do I convert a string that's a formatted number, back to a number?

  Decimal percent = 55.76;
  String strPercent = String.Format("{0:0.0}%", percent);
  Decimal dollars = 33.5;
  String strDollars = String.Format("{0:C}", dollars);

Say later, I want to get the percent and dollar value back, as numbers. Is there any built-in way to do this using C# and asp.net? I know how I use regex and a String function, but I read about a Decimal.Parse() function from http://msdn.microsoft.com/en-us/library/ks098hd7(vs.71).aspx.

Is there a built-in function to do this? If yes, how can I use it?

回答1:

Using Decimal.Parse, you can pass a System.Globalization.NumberStyles to control how strings are parsed. This will let you convert currency strings back to decimals easily. Unfortunately NumberStyles does not support percentages, so you'll still have to strip the percentage symbol out separately.

        Decimal percent = 55.76M;
        String strPercent = String.Format("{0:0.0}%", percent);
        Decimal dollars = 33.5M;
        String strDollars = String.Format("{0:C}", dollars);

        Decimal parsedDollars = Decimal.Parse(strDollars, NumberStyles.Currency);

        Decimal parsedPercent = Decimal.Parse(
            strPercent.Replace(
                NumberFormatInfo.CurrentInfo.PercentSymbol,
                String.Empty));

See the NumberStyles documentation for more info.

回答2:

int.Parse, double.Parse, etc are your friends.

Edit: Missed the punctuation part. Will reinvestigate and come up with something better.

Edit 2: It turns out int.Parse actually has an overload to take the format string: http://msdn.microsoft.com/en-us/library/c09yxbyt.aspx

来源：https://stackoverflow.com/questions/5615551/c-sharp-is-there-a-built-in-function-to-convert-a-formatted-string-back-to-a-num