two decimal places for decimal/money field

问题:

I have a table with money field in my database. I have created entity and created decimal property for that money field. When the value of that field is displayed on My MVC3 view, It has four zeros 0000 after decimal like this : 5489.0000. I want to show only two 00 or decimal places. How can I fix it. Why it is showing four decimal places even I declared property as decimal.

Please suggest.

回答1:

The SQL Server money datatype internally is a 64-bit integer with an implied scale of 4 decimal places. To quote Books Online, it is accurate "to ten-thousandsth of a currency unit." It is, the rough equivalent of a decimal(19,4).

The reason for the scale of 4 rather than 2 is to maintain precision in the results of arithmetic. Your ordinary currency value has a scale of 2 (e.g. $3.27) Multiplication or division of two numbers scaled to 2 decimal places gives a results that is precise to 4 decimal places: 9.23 divided by 3.27 yields a result of 2.82262996941896 (approximately). You can carry the result to whatever accuracy (number of decimal places) you desire. However, the result is only precise to 4 decimal places (2.8226) as the original values were only precise to 2 decimal places. That measurement is precise to within 1/2 of the smallest unit specified (+/- 0.005).

But I digress.

As a result of a SQL Server money value having an implied scale of 4, ADO.Net converts the value to a System.Decimal with a scale of 4. And since System.Decimal tracks scale, when you convert it to string, you get 4 decimal places.

To get fewer, you can

• Round it before conversion, using the appropriate Decimal.Round() overload, or
• Format it as desired (eg. (3.27M).ToString("0.00") ;.

Hope this helps.

This program:

namespace Sandbox
{
  using System ;
  class Program
  {
    static void Main( string[] args )
    {
      decimal pi     = (decimal) Math.PI ;
      string  piText = pi.ToString("0.00");
      Console.WriteLine("PI to 2 decimal places is {0} one way, and {1:0.00} another" , piText , pi ) ;
      return;
    }
  }
}

Produces what you'd expect:

PI to 2 decimal places is 3.14 one way, and 3.14 another

Cheers,

N.

回答2:

You have to format the string.

One thing you can do if it money you want to display is:

static void Main () 
{
    decimal x = 0.999m;
    decimal y = 9999999999999999999999999999m;
    Console.WriteLine("My amount = {0:C}", x);
    Console.WriteLine("Your amount = {0:C}", y);
}

}

OUTPUT: Output

My amount = $1.00
Your amount = $9,999,999,999,999,999,999,999,999,999.00

the {0:C} is the currency Format

Hope this helps!

回答3:

Here is everything you need to know about formatting strings.

http://blog.stevex.net/string-formatting-in-csharp/

回答4:

I used this and it worked:

YourDecField.ToString("N")