C#实现字符串格式化的示例代码

var currentTime = DateTime.Now;
 
Console.WriteLine($"{currentTime:yyyy年MM月dd日 HH时:mm分:ss秒:ffff毫秒}"); // 日期格式化
Console.WriteLine(currentTime.ToString("yyyy-MM-dd HH:mm:ss:ffff"));
Console.WriteLine($"{currentTime:D}");
Console.WriteLine($"{currentTime:d}");
Console.WriteLine($"{currentTime:F}");
Console.WriteLine($"{currentTime:f}");
Console.WriteLine($"{currentTime:G}");
Console.WriteLine($"{currentTime:g}");
Console.WriteLine($"{currentTime:m}");
Console.WriteLine($"{currentTime:T}");
Console.WriteLine($"{currentTime:t}");
 
var left = "left";
var right = "right";
Console.WriteLine($"Span:{left,-20}|{right,20}");   // 左右对齐
Console.WriteLine($"Span:{left,-20}|{right,20}");
Console.WriteLine($"Span:{left,-20}|{right,20}");
 
var holder01 = "{holder01}";
var holder02 = @"\{holder02}";
Console.WriteLine($"holder01:{{{holder01}}}");
Console.WriteLine($"holder01:{{{holder02}}}");
 
var sex = 0;
Console.WriteLine($"{(sex == 0 ? "Male" : "Female")}");   // 表达式需要用()包起来
 
string? value = null;
Console.WriteLine($"value is {(value ?? "test value")}"); // 表达式需要用()包起来
 
var ob = new { name = "Lee", age = 11 };
Console.WriteLine($"name: {ob.name}, age: {ob.age}");     // 对象成员格式化
 
long num = 123456;
Console.WriteLine($"{num:D8}"); // 格式化成8位的十进制
 
Console.WriteLine($"{num:N2}"); // 格式化成保留2位小数并用千分位符号隔开的字符串
 
Console.WriteLine($"{num:C3}"); // 格式化成货币小数点保留3位
 
Console.WriteLine($"{num:X000}"); // 格式化成十六进制
 
Console.WriteLine($"{0.19:P}");  // 格式化百分比
Console.WriteLine($"{0.19:P1}");