C# 从字符串中获取具有特定模式的子字符串
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/14870551/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
C# Get substring with specific pattern from string
提问by bale3
I have a list of strings like this:
我有一个像这样的字符串列表：
List<string> list = new List<string>();
list.Add("Item 1: #item1#");
list.Add("Item 2: #item2#");
list.Add("Item 3: #item3#");
How can I get and add the substrings #item1#, #item2# etc into a new list?
如何获取子字符串#item1#、#item2# 等并将其添加到新列表中？
I am only able to get the complete string if it contains a "#" by doing this:
如果它包含“#”，我只能通过这样做来获取完整的字符串：
foreach (var item in list)
{
if(item.Contains("#"))
{
//Add item to new list
}
}
采纳答案by Botz3000
You could have a look at Regex.Match. If you know a little bit about regular expressions (in your case it would be a quite simple pattern: "#[^#]+#"), you can use it to extract all items starting and ending with '#'with any number of other characters other than '#'in between.
你可以看看Regex.Match。如果您对正则表达式略知一二（在您的情况下，这将是一个非常简单的模式：）"#[^#]+#"，您可以使用它来提取'#'以任意数量的其他字符开头和结尾的所有项目，而不是'#'介于两者之间。
Example:
例子：
Match match = Regex.Match("Item 3: #item3#", "#[^#]+#");
if (match.Success) {
Console.WriteLine(match.Captures[0].Value); // Will output "#item3#"
}
回答by yvesonline
How about this:
这个怎么样：
List<string> substring_list = new List<string>();
foreach (string item in list)
{
int first = item.IndexOf("#");
int second = item.IndexOf("#", first);
substring_list.Add(item.Substring(first, second - first);
}
回答by Ash
You could do that by simply using:
您可以通过简单地使用：
List<string> list2 = new List<string>();
list.ForEach(x => list2.Add(x.Substring(x.IndexOf("#"), x.Length - x.IndexOf("#"))));
回答by masterlopau
try this.
尝试这个。
var itemList = new List<string>();
foreach(var text in list){
string item = text.Split(':')[1];
itemList.Add(item);
}
回答by masterlopau
LINQ would do the job nicely:
LINQ 可以很好地完成这项工作：
var newList = list.Select(s => '#' + s.Split('#')[1] + '#').ToList();
Or if you prefer query expressions:
或者，如果您更喜欢查询表达式：
var newList = (from s in list
select '#' + s.Split('#')[1] + '#').ToList();
Alternatively, you can use regular expressions as suggested with Botz3000 and combine those with LINQ:
或者，您可以按照 Botz3000 的建议使用正则表达式，并将它们与 LINQ 结合使用：
var newList = new List(
from match in list.Select(s => Regex.Match(s, "#[^#]+#"))
where match.Success
select match.Captures[0].Value
);
回答by Sergey Brunov
The code will solve your problem.
But if the string does not contain#item#then the original string will be used.
该代码将解决您的问题。但如果字符串不包含，#item#则将使用原始字符串。
var inputList = new List<string>
{
"Item 1: #item1#",
"Item 2: #item2#",
"Item 3: #item3#",
"Item 4: item4"
};
var outputList = inputList
.Select(item =>
{
int startPos = item.IndexOf('#');
if (startPos < 0)
return item;
int endPos = item.IndexOf('#', startPos + 1);
if (endPos < 0)
return item;
return item.Substring(startPos, endPos - startPos + 1);
})
.ToList();
回答by Jim D'Angelo
Here's another way using a regex with LINQ. (Not sure your exact requirements reference the regex, so now you may have two problems.)
这是在 LINQ 中使用正则表达式的另一种方法。（不确定您的确切要求是否引用了正则表达式，所以现在您可能有两个问题。）
var list = new List<string> ()
{
"Item 1: #item1#",
"Item 2: #item2#",
"Item 3: #item3#",
"Item 4: #item4#",
"Item 5: #item5#",
};
var pattern = @"#[A-za-z0-9]*#";
list.Select (x => Regex.Match (x, pattern))
.Where (x => x.Success)
.Select (x => x.Value)
.ToList ()
.ForEach (Console.WriteLine);
Output:
输出：
#item1#
#item2#
#item3#
#item4#
#item5#
#item1#
#item2#
#item3#
#item4#
#item5#
