|
C |
货币 |
2.5.ToString("C") |
￥2.50 |
|
D |
十进制数 |
25.ToString("D5") |
00025 |
|
E |
科学型 |
25000.ToString("E") |
2.500000E+005 |
|
F |
固定点 |
25.ToString("F2") |
25.00 |
|
G |
常规 |
2.5.ToString("G") |
2.5 |
|
N |
数字 |
2500000.ToString("N") |
2,500,000.00 |
|
X |
十六进制 |
255.ToString("X") |
FF |
formatCode 是可选的格式化代码字符串。（详细内容请搜索“格式化字符串”查看）
必须用“{”和“}”将格式与其他字符分开。如果恰好在格式中也要使用大括号，可以用连续的两个大括号表示一个大括号，即： “{{”或者“}}”。
常用格式举例：
（1） int i=12345;
this.textBox1.Text=i.ToString();
//结果 12345（this指当前对象，或叫当前类的实例）
this.textBox2.Text=i.ToString("d8");
//结果 00012345
（2） int i=123;
double j=123.45;
string s1=string.Format("the value is {0,7:d}",i);
string s2=string.Format("the value is {0,7:f3}",j);
this.textBox1.Text=s1 ;
//结果 the value is 123
this.textBox2.Text=s2;
//结果 the value is 123.450
（3）double i=12345.6789;
this.textBox1.Text=i.ToString("f2"); //结果 12345.68
this.textBox2.Text=i.ToString("f6");
//结果 12345.678900
（4）double i=12345.6789;
this.textBox1.Text=i.ToString("n"); //结果 12,345.68
this.textBox2.Text=i.ToString(“n4”); //结果 12,345.6789
（5）double i=0.126;
string s=string.Format("the value is {0:p}",i);
this.textBox1.Text=i.ToString("p"); //结果 12.6%
this.textBox2.Text=s; //结果 the value is 12.6%
（6） DateTime dt =new DateTime(2003,5,25);
this.textBox1.Text=dt.ToString("yy.M.d");
//结果 03.5.25
this.textBox2.Text=dt.ToString(“yyyy年M月”);
//结果 2003年5月
Convert.ToDateTime("2005/12/22 22:22:22").ToString("yyyy/MM/dd HH:mm:ss")
"2005/12/22 22:22:22"
（7） int i=123;
double j=123.45;
string s=string.Format("i:{0,-7},j:{1,7}",i,j);
//-7表示左对齐，占7位
this.textBox1.Text=s ;
//结果i:123 ,j: 123.45
Byte.ToString 方法 (String, IFormatProvider)的C#例子
下面的代码示例使用 ToString 方法的几个重载格式化 Byte 值。
// Example for the Byte.ToString( ) methods.
using System;
using System.Globalization;
class ByteToStringDemo
{
static void RunToStringDemo( )
{
byte smallValue = 13;
byte largeValue = 234;
// Format the Byte values without and with format strings.
Console.WriteLine( "/nIFormatProvider is not used:" );
Console.WriteLine( " {0,-20}{1,10}{2,10}",
"No format string:", smallValue.ToString( ),
largeValue.ToString( ) );
Console.WriteLine( " {0,-20}{1,10}{2,10}",
"'X2' format string:", smallValue.ToString( "X2" ),
largeValue.ToString( "X2" ) );
// Get the NumberFormatInfo object from the
// invariant culture.
CultureInfo culture = new CultureInfo( "" );
NumberFormatInfo numInfo = culture.NumberFormat;
// Set the digit grouping to 1, set the digit separator
// to underscore, and set decimal digits to 0.
numInfo.NumberGroupSizes = new int[ ] { 1 };
numInfo.NumberGroupSeparator = "_";
numInfo.NumberDecimalDigits = 0;
// Use the NumberFormatInfo object for an IFormatProvider.
Console.WriteLine(
"/nA NumberFormatInfo object with digit group " +
"size = 1 and /ndigit separator " +
"= '_' is used for the IFormatProvider:" );
Console.WriteLine( " {0,-20}{1,10}{2,10}",
"No format string:", smallValue.ToString( numInfo ),
largeValue.ToString( numInfo ) );
Console.WriteLine( " {0,-20}{1,10}{2,10}",
"'N' format string:",
smallValue.ToString( "N", numInfo ),
largeValue.ToString( "N", numInfo ) );
}
static void Main( )
{
Console.WriteLine( "This example of/n" +
" Byte.ToString( ),/n" +
" Byte.ToString( String ),/n" +
" Byte.ToString( IFormatProvider ), and/n" +
" Byte.ToString( String, IFormatProvider )/n" +
"generates the following output when formatting " +
"Byte values /nwith combinations of format " +
"strings and IFormatProvider." );
RunToStringDemo( );
}
}
/*
This example of
Byte.ToString( ),
Byte.ToString( String ),
Byte.ToString( IFormatProvider ), and
Byte.ToString( String, IFormatProvider )
generates the following output when formatting Byte values
with combinations of format strings and IFormatProvider.
IFormatProvider is not used:
No format string: 13 234
'X2' format string: 0D EA
A NumberFormatInfo object with digit group size = 1 and
digit separator = '_' is used for the IFormatProvider:
No format string: 13 234
'N' format string: 1_3 2_3_4
*/