c# - 将 "mask"应用于字符串

Question

我有一个标志枚举 (int) 掩码，我需要将它转换为表示星期几的字符串。

说这是完整的字符串和任意掩码

strFullWeek = "MTWtFSs"
strWeekMask = "0100110"
-----------------------
strResult   = "-T--FS-"

你建议用什么方法从 full week 和 mask 字符串中获取 strResult？

更新

这是我的“整个上下文”(VB.NET)

<Flags()> Public Enum Week
  Monday = 1
  Tuesday = 2
  Wednesday = 4
  Thursday = 8
  Friday = 16
  Saturday = 32
  Sunday = 64
End Enum

Dim mondayOrSunday = Week.Monday Or Week.Sunday
Dim strDays = "MTWtFSs"

Dim strMondayOrSundayBinary = Convert.ToString(
  mondayOrSunday, 2).PadRight(7, CChar("0"))

Dim charMondayOrSunday = strDays.Zip(
  strMondayOrSundayBinary,
  Function(day, mask) If(mask = CChar("1"), day, CChar("-"))).ToArray()

Dim strMondayOrSunday = New String(charMondayOrSunday)

Console.WriteLine("{0} I see as {1}",
                  mondayOrSunday,
                  strMondayOrSunday)

Answer 1

有一种相当简洁的 LINQ 方式:

var chars = strFullWeek.Zip(strWeekMask, (day, mask) => mask == '1' ? day : '-'))
                       .ToArray();
string text = new string(chars);

它不会非常有效，但它可能足够好......

编辑:好的，假设您对枚举版本的 C# 代码感到满意

// TODO: Rename "Week" to comply with .NET naming conventions
Week mask = Week.Monday | Week.Sunday;
var chars = strFullWeek.Select((value, index) => (int) mask & (1 << index) != 0) 
                                                 ? value : '-')
                       .ToArray();
string text = new string(chars);