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

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)

下面是Uwe Keim的方法的替代方案，它仍然保持相同的方法调用:

var example1 = MyCustomFormat(123.1);  // Output: 123.10
var example2 = MyCustomFormat(123.95); // Output: 123.95
var example3 = MyCustomFormat(123);    // Output: 123

MyCustomFormat是这样的:

public static string MyCustomFormat( double myNumber )
{
    var str (string.Format("{0:0.00}", myNumber))
    return (str.EndsWith(".00") ? str.Substring(0, strLastIndexOf(".00")) : str;
}

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]

如果其他答案都不适合你，这可能是因为你在OnLoad函数中绑定了控件的ContentProperty，这意味着这将不起作用:

private void UserControl_Load(object sender, RoutedEventArgs e)
{
  Bind.SetBindingElement(labelName, String.Format("{0:0.00}", PropertyName), Label.ContentProperty) 
}

解决方案很简单:在xaml中有一个ContentStringFormat属性。所以当你创建标签时，这样做:

//if you want the decimal places definite
<Label Content="0" Name="labelName" ContentStringFormat="0.00"/>

Or

//if you want the decimal places to be optional
<Label Content="0" Name="labelName" ContentStringFormat="0.##"/>