像这样的东西也可以:

String.Format("{0:P}", decimal.Parse(Resellers.Fee)).Replace(".00", "")

老问题了，但我想在我看来添加一个最简单的选项。

没有数千个隔板:

value.ToString(value % 1 == 0 ? "F0" : "F2")

有成千上万的隔板:

value.ToString(value % 1 == 0 ? "N0" : "N2")

与String相同。格式:

String.Format(value % 1 == 0 ? "{0:F0}" : "{0:F2}", value) // Without thousands separators
String.Format(value % 1 == 0 ? "{0:N0}" : "{0:N2}", value) // With thousands separators

如果你在很多地方都需要它，我会在一个扩展方法中使用这个逻辑:

public static string ToCoolString(this decimal value)
{
    return value.ToString(value % 1 == 0 ? "N0" : "N2"); // Or F0/F2 ;)
}

Try:

String.Format("{0:0.00}", Convert.ToDecimal(totalPrice));

很抱歉重新激活这个问题，但我在这里没有找到正确的答案。

在格式化数字时，可以使用0作为必选位置，使用#作为可选位置。

So:

// just two decimal places
String.Format("{0:0.##}", 123.4567);      // "123.46"
String.Format("{0:0.##}", 123.4);         // "123.4"
String.Format("{0:0.##}", 123.0);         // "123"

你也可以把0和#结合起来。

String.Format("{0:0.0#}", 123.4567)       // "123.46"
String.Format("{0:0.0#}", 123.4)          // "123.4"
String.Format("{0:0.0#}", 123.0)          // "123.0"

对于这种格式化方法，总是使用CurrentCulture。对于某些文化。将改为，。

原问题的答案:

最简单的解决方案来自@Andrew(这里)。所以我个人会使用这样的方法:

var number = 123.46;
String.Format(number % 1 == 0 ? "{0:0}" : "{0:0.00}", number)

最近的一个项目也有类似的需求。我写了这个十进制扩展法， 它使用货币(“C”)格式说明符。除了删除零之外，它还可以选择十进制数字精度、货币符号、分隔符和区域性。

public static DecimalExtension{

     public static string ToCurrency(this decimal val, 
                                     int precision = 2, 
                                     bool currencySymbol = false, 
                                     bool separator = false, 
                                     CultureInfo culture = null)
      {     
         if(culture == null) culture = new CultureInfo("en-US");
                                                   
         NumberFormatInfo nfi = culture.NumberFormat;
         nfi.CurrencyDecimalDigits = precision;
            
         string zeros = new String('0', precision);       
                    
         //Remove zeros
         var result = val.ToString("C",fi).Replace(nfi.CurrencyDecimalSeparator + zeros,"");
                     
         if(!separator) result = result.Replace(nfi.CurrencyGroupSeparator,"");
                    
         return currencySymbol? result: result.Replace(nfi.CurrencySymbol,"");      
        }   
}

例子:

decimal Total = 123.00M;
Console.WriteLine(Total.ToCurrency());  
//output: 123

decimal Total = 1123.12M;
Console.WriteLine(Total.ToCurrency()); 
//Output:  1123.12

Console.WriteLine(Total.ToCurrency(4));
//Output:  1123.1200

Console.WriteLine(Total.ToCurrency(2,true,true));
//output:  $1,123.12
 
CultureInfo culture = new CultureInfo("pt-BR")  //Brazil
Console.WriteLine(Total.ToCurrency(2,true,true, culture));
//output:  R$ 1.123,12

如果你的程序需要快速运行，调用value. tostring (formatString)可以获得比$"{value:formatString}"和string快35%的字符串格式化性能。格式(formatString值)。

Data

Code

using System;
using System.Diagnostics;

public static class StringFormattingPerformance
{
   public static void Main()
   {
      Console.WriteLine("C# String Formatting Performance");
      Console.WriteLine("Milliseconds Per 1 Million Iterations - Best Of 5");
      long stringInterpolationBestOf5 = Measure1MillionIterationsBestOf5(
          (double randomDouble) =>
          {
             return $"{randomDouble:0.##}";
          });
      long stringDotFormatBestOf5 = Measure1MillionIterationsBestOf5(
          (double randomDouble) =>
          {
             return string.Format("{0:0.##}", randomDouble);
          });
      long valueDotToStringBestOf5 = Measure1MillionIterationsBestOf5(
          (double randomDouble) =>
          {
             return randomDouble.ToString("0.##");
          });
      Console.WriteLine(
$@"            $""{{value:formatString}}"": {stringInterpolationBestOf5} ms
 string.Format(formatString, value): {stringDotFormatBestOf5} ms
       value.ToString(formatString): {valueDotToStringBestOf5} ms");
   }

   private static long Measure1MillionIterationsBestOf5(
       Func<double, string> formatDoubleUpToTwoDecimalPlaces)
   {
      long elapsedMillisecondsBestOf5 = long.MaxValue;
      for (int perfRunIndex = 0; perfRunIndex < 5; ++perfRunIndex)
      {
         var random = new Random();
         var stopwatch = Stopwatch.StartNew();
         for (int i = 0; i < 1000000; ++i)
         {
            double randomDouble = random.NextDouble();
            formatDoubleUpToTwoDecimalPlaces(randomDouble);
         }
         stopwatch.Stop();
         elapsedMillisecondsBestOf5 = Math.Min(
            elapsedMillisecondsBestOf5, stopwatch.ElapsedMilliseconds);
      }
      return elapsedMillisecondsBestOf5;
   }
}

代码的输出

C# String Formatting Performance
Milliseconds Per 1 Million Iterations - Best Of 5
            $"{value:formatString}": 419 ms
 string.Format(formatString, value): 419 ms
       value.ToString(formatString): 264 ms

参考文献

自定义数字格式字符串[learn.microsoft.com]

Qt图表BarChart示例[doc.qt.io]