c#中各种格式化参考文章

//占位符表示规则: index,[width], [G,E,F,N,C,D,X][保留的小数位数]

                    //具体见:         http://blog.youkuaiyun.com/RainyLin/article/details/2282944
                    //G  E/F中较短的表现形式  保留几位[有效数字]  G4
                    //E  科学计数法
                    //F  浮点数计数法
                    //N  带有分隔号的浮点数
                    //C  带有货币符号和千分位的浮点数
                    //D  用于整数  表示10进制
                    //X  用于整数  表示16进制

                    Console.WriteLine("{0, -15:G4}", 78545412345678);

                    //只要有1个逗号就会格式化为千分位
                    Console.WriteLine(String.Format("{0:#,0.##}", 314256.2225));

                    //toString 和 String.Format()
                    double a = 15563.22567;
                    Console.WriteLine(a.ToString("C3"));
                    Console.WriteLine(String.Format("{0:C3}", a));

                    double b = 87654321.12543;
                    int c = 12345678;

                    //逗号居然可以直接相当于做除法保留位数运算
                    Console.WriteLine("---------");
                    Console.WriteLine(String.Format("{0:0}", b));
                    Console.WriteLine(String.Format("{0:0,}", b));
                    Console.WriteLine(String.Format("{0:0,,}", b));
                    Console.WriteLine(String.Format("{0:0,,,}", b));

                    //%的使用
                    double d = 1562.233;
                    Console.WriteLine("%%%%%%%%%%%");
                    Console.WriteLine(String.Format("{0:#.00%}", d));

                    //"abc"文本的使用
                    Console.WriteLine(String.Format("{0:'文本'0.00}", d));
                    Console.WriteLine(String.Format("{0:文本0.00}", d));

                    //\"输出双引号
                    Console.WriteLine(String.Format("\"ni hao\""));
                    //@符号使用
                    Console.WriteLine(String.Format(@"--"));

                    // 日期格式化
                    DateTime now = DateTime.Now;
                    Console.WriteLine(now);
                    Console.WriteLine(now.ToString("yyyy年-MM月-dd日 HH时-mm分-ss秒 fffffff毫秒   tt"));
                    Console.WriteLine(now.ToString("yyyy年-M月-d日"));

                    //字符串格式化见如下文章
                    //日期格式化   http://www.cnblogs.com/345563452/archive/2009/03/03/1402471.html
                    //数字格式化   http://www.cnblogs.com/345563452/archive/2009/03/03/1402497.html
                    //             http://blog.youkuaiyun.com/RainyLin/article/details/2282944
                    //格式化大全   http://www.cnblogs.com/345563452/archive/2009/03/15/1412437.html