string name = "Mark";
var date = DateTime.Now;

// Composite formatting:
Console.WriteLine("Hello, {0}! Today is {1}, it's {2:HH:mm} now.", name, date.DayOfWeek, date);
// String interpolation:
Console.WriteLine($"Hello, {name}! Today is {date.DayOfWeek}, it's {date:HH:mm} now.");
// Both calls produce the same output that is similar to:
// Hello, Mark! Today is Wednesday, it's 19:40 now.


// GET: /HelloWorld/Welcome/ 
// Requires using System.Text.Encodings.Web;
public string Welcome(string name, int numTimes = 1)
return HtmlEncoder.Default.Encode($"Hello {name}, NumTimes is: {numTimes}");



使用 C# 可选参数功能指示,未为 numTimes 参数传递值时该参数默认为 1。

使用 HtmlEncoder.Default.Encode 防止恶意输入(例如通过 JavaScript)损害应用。

在 $"Hello {name}, NumTimes is: {numTimes}" 中使用内插字符串