给出下面的消息格式字符串,例如file0
file1
。我希望能够获得用于显示文本值的“通知”和“名称”值。
str
我尝试使用regex,例如:
var str = @"You have {notifications, plural,
zero {no notifications}
one {one notification}
=42 {a universal amount of notifications}
other {# notifications}
}. Have a nice day, {name}!";
但是以上内容并未考虑到var matches = Regex.Matches(str, @"{(.*?)}");
//var matches = Regex.Matches(str, @"(?<=\{)[^}{]*(?=\})");
var results = matches.Cast<Match>().Select(m => m.Groups[1].Value).Distinct().ToList();
本身用花括号括起来,并且包括不需要的内部值,这些值也用花括号括起来。
因此,简而言之,我只想能够解析上面的字符串{notifications,..
并在返回值处获得str
和notifications
。
诸如name
之类的字符串应仅返回var str2 = @"Hello {name}"
作为值。
编辑
值name
和notifications
不会预先知道-我仅以此为例,说明了我需要从字符串返回的值。
答案 0 :(得分:1)
var str = @"You have {notifications, plural,
zero {no notifications}
one {one notification}
=42 {a universal amount of notifications}
other {# notifications}
}. Have a nice day, {name}!";
// get matches skipping nested curly braces
var matches =
Regex.Matches(str, @"{((?:[^{}]|(?<counter>{)|(?<-counter>}))+(?(counter)(?!)))}");
var results = matches.Cast<Match>().Select(m => m.Groups[1].Value).Distinct()
.Select(v => Regex.Match(v, @"^\w+").Value) // take 1st word
.ToList();
其结果(调试时从Visual Studio Locals窗口复制)
results Count = 2 System.Collections.Generic.List<string>
[0] "notifications"
[1] "name"
...原始答案如下...
关于原始问题中当前解决方案的一件事:
.
与换行符不匹配,因此这是它当前与嵌套值匹配的原因之一(请参阅此source)(本文解决了原始问题中提到的主要挑战-嵌套花括号)
var str = @"You have {notifications, plural,
zero {no notifications}
one {one notification}
=42 {a universal amount of notifications}
other {# notifications}
}. Have a nice day, {name}!";
// get matches skipping nested curly braces
var matches =
Regex.Matches(str, @"{((?:[^{}]|(?<counter>{)|(?<-counter>}))+(?(counter)(?!)))}");
var results = matches.Cast<Match>().Select(m => m.Groups[1].Value).Distinct().ToList();
其结果(调试时从Visual Studio Locals窗口复制)
results Count = 2 System.Collections.Generic.List<string>
[0] "notifications, plural,\r\n zero {no notifications}\r\n one {one notification}\r\n =42 {a universal amount of notifications}\r\n other {# notifications}\r\n "
[1] "name"
(或者如果您要将这些结果打印到控制台):
// Result 0 would look like:
notifications, plural,
zero {no notifications}
one {one notification}
=42 {a universal amount of notifications}
other {# notifications}
// Result 1 would look like:
name
我回到这一点,意识到这个问题只要求单词作为结果。
(我在上面的代码段中附加了select语句,以显示完整的解决方案)
var str = @"You have {notifications, plural,
zero {no notifications}
one {one notification}
=42 {a universal amount of notifications}
other {# notifications}
}. Have a nice day, {name}!";
// get matches skipping nested curly braces
var matches =
Regex.Matches(str, @"{((?:[^{}]|(?<counter>{)|(?<-counter>}))+(?(counter)(?!)))}");
var results = matches.Cast<Match>().Select(m => m.Groups[1].Value).Distinct()
.Select(v => Regex.Match(v, @"^\w+").Value) // take 1st word
.ToList();
其结果(调试时从Visual Studio Locals窗口复制)
results Count = 2 System.Collections.Generic.List<string>
[0] "notifications"
[1] "name"
(我刚刚发现这很有趣,花了一些时间进行研究/学习,并认为它值得包含更多相关信息)
对话here和here包含针对使用正则表达式解决此类问题的一些观点。
不管以上观点如何,.NET创建者都认为实现平衡组定义是适当的-此答案使用的功能是
答案 1 :(得分:0)
执行此操作的一种方法是编写一种方法,该方法将基于输入count
和字符串的单数(或复数)形式为您格式化字符串:
private static string FormatWord(int count, string singluar)
{
return Format(count, singluar, singluar + "s");
}
private static string FormatWord(int count, string singular, string plural)
{
return count == 0 ? "no " + plural
: count == 1 ? "one " + singular
: count == 42 ? "a universal number of " + plural
: count + " " + plural;
}
然后在使用中它可能看起来像:
private static void Main()
{
var name = "User";
while (true)
{
var count = GetIntFromUser("Enter notification count: ");
Console.WriteLine($"You have {FormatWord(count, "notification")}. " +
$"Have a nice day, {name}");
}
}
请注意,该方法还使用了辅助方法来从用户那里获取强类型整数:
private static int GetIntFromUser(string prompt, Func<int, bool> validator = null)
{
int result;
var cursorTop = Console.CursorTop;
do
{
ClearSpecificLineAndWrite(cursorTop, prompt);
} while (!int.TryParse(Console.ReadLine(), out result) ||
!(validator?.Invoke(result) ?? true));
return result;
}
private static void ClearSpecificLineAndWrite(int cursorTop, string message)
{
Console.SetCursorPosition(0, cursorTop);
Console.Write(new string(' ', Console.WindowWidth));
Console.SetCursorPosition(0, cursorTop);
Console.Write(message);
}