占位符格式化数字

可以用ToString()方法来格式化数字的格式

具体可在MSDN中搜索“零占位符”。

double value;

value = 123;
Console.WriteLine(value.ToString("00000"));
// Displays 00123

value = 1.2;
Console.WriteLine(value.ToString("0.00", CultureInfo.InvariantCulture));
// Displays 1.20
Console.WriteLine(value.ToString("00.00", CultureInfo.InvariantCulture));
// Displays 01.20
Console.WriteLine(value.ToString("00.00", 
                  CultureInfo.CreateSpecificCulture("da-DK")));
// Displays 01,20

value = .56;
Console.WriteLine(value.ToString("0.0", CultureInfo.InvariantCulture));
// Displays 0.6

value = 1234567890;
Console.WriteLine(value.ToString("#,#", CultureInfo.InvariantCulture));    
// Displays 1,234,567,890      
Console.WriteLine(value.ToString("#,#", 
                  CultureInfo.CreateSpecificCulture("el-GR")));    
// Displays 1.234.567.890   








 double value;

      value = 1.2;
      Console.WriteLine(value.ToString("#.##", CultureInfo.InvariantCulture));
      // Displays 1.2

      value = 123;
      Console.WriteLine(value.ToString("#####"));
      // Displays 123

      value = 123456;
      Console.WriteLine(value.ToString("[##-##-##]"));      
       // Displays [12-34-56]

      value = 1234567890;
      Console.WriteLine(value.ToString("#"));
      // Displays 1234567890
      Console.WriteLine(value.ToString("(###) ###-####"));
      // Displays (123) 456-7890




   double value;

      value = 1.2;
      Console.WriteLine(value.ToString("0.00", CultureInfo.InvariantCulture));
      // Displays 1.20
      Console.WriteLine(value.ToString("00.00", CultureInfo.InvariantCulture));
      // Displays 01.20
      Console.WriteLine(value.ToString("00.00", 
                        CultureInfo.CreateSpecificCulture("da-DK")));
      // Displays 01,20

      value = .086;
      Console.WriteLine(value.ToString("#0.##%", CultureInfo.InvariantCulture)); 
      // Displays 8.6%

      value = 86000;
      Console.WriteLine(value.ToString("0.###E+0", CultureInfo.InvariantCulture));
       // Displays 8.6E+4






double value = 1234567890;
Console.WriteLine(value.ToString("#,#", CultureInfo.InvariantCulture));
// Displays 1,234,567,890      
Console.WriteLine(value.ToString("#,##0,,", CultureInfo.InvariantCulture));
// Displays 1,235          




double value = 1234567890;
      Console.WriteLine(value.ToString("#,,", CultureInfo.InvariantCulture));    
      // Displays 1235   
      Console.WriteLine(value.ToString("#,,,", CultureInfo.InvariantCulture));
       // Displays 1  
      Console.WriteLine(value.ToString("#,##0,,", CultureInfo.InvariantCulture));       
       // Displays 1,235



double value = .086;
Console.WriteLine(value.ToString("#0.##%", CultureInfo.InvariantCulture));
// Displays 8.6%      




double value = 86000;
Console.WriteLine(value.ToString("0.###E+0", CultureInfo.InvariantCulture));
// Displays 8.6E+4
Console.WriteLine(value.ToString("0.###E+000", CultureInfo.InvariantCulture));
// Displays 8.6E+004
Console.WriteLine(value.ToString("0.###E-000", CultureInfo.InvariantCulture));
// Displays 8.6E004



double posValue = 1234;
double negValue = -1234;
string fmt = "##;(##)";
Console.WriteLine(posValue.ToString(fmt));    // Displays 1234
Console.WriteLine(negValue.ToString(fmt));    // Displays (1234)