Question

你们如何将多线划分成线?

我知道这种方式。

var result = input.Split("

".ToCharArray(), StringSplitOptions.RemoveEmptyEntries);

视而不见,失去空线。是否有更好的解决办法?

Answer 1

如果看上去的话,就只是删除了“ToCharArray的不必要密码。
If you want to split by either or , you ve got two options:
- Use an array literal – but this will give you empty lines for Windows-style line endings :
```
var result = text.Split(new [] {  
 ,  
  });
```
- Bart指出,使用定期表述:
```
var result = Regex.Split(text, "
|
|
");
```
如果你想要保留空线,那么你为什么明确地告诉C#,将他们赶走? (String SplitOptions para amount) - use String SplitOptions. 无。

Answer 2

using (StringReader sr = new StringReader(text)) {
    string line;
    while ((line = sr.ReadLine()) != null) {
        // do something
    }
}

Answer 3

Update: See here for an alternative/async solution.

这一工作非常出色,比雷克快:

input.Split(new[] {"
", "
", "
"}, StringSplitOptions.None)

It is important to have " " first in the array so that it s taken as one line break. The above gives the same results as either of these Regex solutions:

Regex.Split(input, "
|
|
")

Regex.Split(input, "
?
|
")

除此以外,雷克斯岛的增长率大约为10倍。我在此检验:

Action<Action> measure = (Action func) => {
    var start = DateTime.Now;
    for (int i = 0; i < 100000; i++) {
        func();
    }
    var duration = DateTime.Now - start;
    Console.WriteLine(duration);
};

var input = "";
for (int i = 0; i < 100; i++)
{
    input += "1 
2
3
4

5 

 6
7
 8
";
}

measure(() =>
    input.Split(new[] {"
", "
", "
"}, StringSplitOptions.None)
);

measure(() =>
    Regex.Split(input, "
|
|
")
);

measure(() =>
    Regex.Split(input, "
?
|
")
);

<<>Output>:

00:00:03.8527616

00:00:31.8017726

00:00:32.5557128

页: 1

public static class StringExtensionMethods
{
    public static IEnumerable<string> GetLines(this string str, bool removeEmptyLines = false)
    {
        return str.Split(new[] { "
", "
", "
" },
            removeEmptyLines ? StringSplitOptions.RemoveEmptyEntries : StringSplitOptions.None);
    }
}

<><>Usage:

input.GetLines()      // keeps empty lines

input.GetLines(true)  // removes empty lines

Answer 4

您可使用Regex。内容:

string[] tokens = Regex.Split(input, @"
?
|
");

Edit: 添加<>>>,以核算(原)麦克风终点站。

Answer 5

如果你想要保持空洞的界线,就只能去掉“强谋”。

var result = input.Split(System.Environment.NewLine.ToCharArray());

Answer 6

string[] lines = input.Split(new[] {  
 ,  
  }, StringSplitOptions.RemoveEmptyEntries);

Answer 7

我有,但根据Jack s answer,~~s>大大加快了~~,因为~~的工作进度不错,虽然稍慢。~~

public static class StringExtensionMethods { public static IEnumerable<string> GetLines(this string str, bool removeEmptyLines = false) { using (var sr = new StringReader(str)) { string line; while ((line = sr.ReadLine()) != null) { if (removeEmptyLines && String.IsNullOrWhiteSpace(line)) { continue; } yield return line; } } } }

<><>Usage:

input.GetLines() // keeps empty lines input.GetLines(true) // removes empty lines

<>试验:

Action<Action> measure = (Action func) => { var start = DateTime.Now; for (int i = 0; i < 100000; i++) { func(); } var duration = DateTime.Now - start; Console.WriteLine(duration); }; var input = ""; for (int i = 0; i < 100; i++) { input += "1 2 3 4 5 6 7 8 "; } measure(() => input.Split(new[] { " ", " ", " " }, StringSplitOptions.None) ); measure(() => input.GetLines() ); measure(() => input.GetLines().ToList() );

<<>Output>:

00:03.9603894

00:00.0029996

00:04.8221971

Answer 8

略微扭曲了,但一个导管组这样做:

public static IEnumerable<string> Lines(this string Text)
{
    int cIndex = 0;
    int nIndex;
    while ((nIndex = Text.IndexOf(Environment.NewLine, cIndex + 1)) != -1)
    {
        int sIndex = (cIndex == 0 ? 0 : cIndex + 1);
        yield return Text.Substring(sIndex, nIndex - sIndex);
        cIndex = nIndex;
    }
    yield return Text.Substring(cIndex + 1);
}

之后,你可以呼吁:

var result = input.Lines().ToArray();

Answer 9

    private string[] GetLines(string text)
    {

        List<string> lines = new List<string>();
        using (MemoryStream ms = new MemoryStream())
        {
            StreamWriter sw = new StreamWriter(ms);
            sw.Write(text);
            sw.Flush();

            ms.Position = 0;

            string line;

            using (StreamReader sr = new StreamReader(ms))
            {
                while ((line = sr.ReadLine()) != null)
                {
                    lines.Add(line);
                }
            }
            sw.Close();
        }



        return lines.ToArray();
    }

Answer 10


It s tricky to handle mixed line endings properly. As we know, the line termination characters can be "Line Feed" (ASCII 10, 
, x0A, u000A), "Carriage Return" (ASCII 13, 
, x0D, u000D), or some combination of them. Going back to DOS, Windows uses the two-character sequence CR-LF u000Du000A, so this combination should only emit a single line. Unix uses a single u000A, and very old Macs used a single u000D character. The standard way to treat arbitrary mixtures of these characters within a single text file is as follows:


each and every CR or LF character should skip to the next line EXCEPT...
...if a CR is immediately followed by LF (u000Du000A) then these two together skip just one line.
String.Empty is the only input that returns no lines (any character entails at least one line)
The last line must be returned even if it has neither CR nor LF.


上一条规则描述了StringReader.ReadLine和相关功能,以下功能产生相同的结果。 这是一个高效的“C#细线突破功能,可随意执行这些准则,正确处理CR/LF的任何任意顺序或组合。 所列举的界线不含任何CR/LF特性。 保留并退回到<代码>。 就业:。

/// <summary>
/// Enumerates the text lines from the string.
///   ⁃ Mixed CR-LF scenarios are handled correctly
///   ⁃ String.Empty is returned for each empty line
///   ⁃ No returned string ever contains CR or LF
/// </summary>
public static IEnumerable<String> Lines(this String s)
{
    int j = 0, c, i;
    char ch;
    if ((c = s.Length) > 0)
        do
        {
            for (i = j; (ch = s[j]) !=  
  && ch !=  
  && ++j < c;)
                ;

            yield return s.Substring(i, j - i);
        }
        while (++j < c && (ch !=  
  || s[j] !=  
  || ++j < c));
}

注:如果你不考虑设立<代码>StringReader的间接费用,则你可使用以下C# 7代码。如前所述,虽然上述例子可能略有提高,但这两项职能都产生了同样的结果。

public static IEnumerable<String> Lines(this String s)
{
    using (var tr = new StringReader(s))
        while (tr.ReadLine() is String L)
            yield return L;
}

Answer 11

划线,不作任何分配。

public static LineEnumerator GetLines(this string text) {
    return new LineEnumerator( text.AsSpan() );
}

internal ref struct LineEnumerator {

    private ReadOnlySpan<char> Text { get; set; }
    public ReadOnlySpan<char> Current { get; private set; }

    public LineEnumerator(ReadOnlySpan<char> text) {
        Text = text;
        Current = default;
    }

    public LineEnumerator GetEnumerator() {
        return this;
    }

    public bool MoveNext() {
        if (Text.IsEmpty) return false;

        var index = Text.IndexOf(  
  ); // 
 or 

        if (index != -1) {
            Current = Text.Slice( 0, index + 1 );
            Text = Text.Slice( index + 1 );
            return true;
        } else {
            Current = Text;
            Text = ReadOnlySpan<char>.Empty;
            return true;
        }
    }


}

Answer 12

很晚,但我用简单的方式收集了延期方法,以利用<代码>TextReader。 ReadLine(:

public static class StringReadLinesExtension
{
    public static IEnumerable<string> GetLines(this string text) => GetLines(new StringReader(text));
    public static IEnumerable<string> GetLines(this Stream stm) => GetLines(new StreamReader(stm));
    public static IEnumerable<string> GetLines(this TextReader reader) {
        string line;
        while ((line = reader.ReadLine()) != null)
            yield return line;
        reader.Dispose();
        yield break;
    }
}

使用该守则确实是三角的:

// If you have the text as a string...
var text = "Line 1
Line 2
Line 3";
foreach (var line in text.GetLines())
    Console.WriteLine(line);
// You can also use streams like
var fileStm = File.OpenRead("c:	estsfile.txt");
foreach(var line in fileStm.GetLines())
    Console.WriteLine(line);

希望有助于人们走出那里。

Update: See here for an alternative/async solution.

友情链接