假设我有一个字符串:

string str = "1111222233334444"; 

我如何把这个字符串分成一定大小的块?

例如,将它分解为4的大小将返回字符串:

"1111"
"2222"
"3333"
"4444"

当前回答

static IEnumerable<string> Split(string str, double chunkSize)
{
    return Enumerable.Range(0, (int) Math.Ceiling(str.Length/chunkSize))
       .Select(i => new string(str
           .Skip(i * (int)chunkSize)
           .Take((int)chunkSize)
           .ToArray()));
}

另一种方法是:

using System;
using System.Collections.Generic;
using System.Linq;

public class Program
{
    public static void Main()
    {

        var x = "Hello World";
        foreach(var i in x.ChunkString(2)) Console.WriteLine(i);
    }
}

public static class Ext{
    public static IEnumerable<string> ChunkString(this string val, int chunkSize){
        return val.Select((x,i) => new {Index = i, Value = x})
                  .GroupBy(x => x.Index/chunkSize, x => x.Value)
                  .Select(x => string.Join("",x));
    }
}

其他回答

List<string> SplitString(int chunk, string input)
{
    List<string> list = new List<string>();
    int cycles = input.Length / chunk;

    if (input.Length % chunk != 0)
        cycles++;

    for (int i = 0; i < cycles; i++)
    {
        try
        {
            list.Add(input.Substring(i * chunk, chunk));
        }
        catch
        {
            list.Add(input.Substring(i * chunk));
        }
    }
    return list;
}

使用正则表达式和Linq:

List<string> groups = (from Match m in Regex.Matches(str, @"\d{4}")
                       select m.Value).ToList();

我觉得这样更有可读性,但这只是个人观点。它也可以是一行代码:)。

它基于@dove解决方案,但作为扩展方法实现。

好处:

扩展方法 涵盖角落案例 分割字符串与任何字符:数字,字母,其他符号

Code

public static class EnumerableEx
{    
    public static IEnumerable<string> SplitBy(this string str, int chunkLength)
    {
        if (String.IsNullOrEmpty(str)) throw new ArgumentException();
        if (chunkLength < 1) throw new ArgumentException();

        for (int i = 0; i < str.Length; i += chunkLength)
        {
            if (chunkLength + i > str.Length)
                chunkLength = str.Length - i;

            yield return str.Substring(i, chunkLength);
        }
    }
}

使用

var result = "bobjoecat".SplitBy(3); // bob, joe, cat

为简洁起见,删除了单元测试(请参阅以前的修订版)

static IEnumerable<string> Split(string str, double chunkSize)
{
    return Enumerable.Range(0, (int) Math.Ceiling(str.Length/chunkSize))
       .Select(i => new string(str
           .Skip(i * (int)chunkSize)
           .Take((int)chunkSize)
           .ToArray()));
}

另一种方法是:

using System;
using System.Collections.Generic;
using System.Linq;

public class Program
{
    public static void Main()
    {

        var x = "Hello World";
        foreach(var i in x.ChunkString(2)) Console.WriteLine(i);
    }
}

public static class Ext{
    public static IEnumerable<string> ChunkString(this string val, int chunkSize){
        return val.Select((x,i) => new {Index = i, Value = x})
                  .GroupBy(x => x.Index/chunkSize, x => x.Value)
                  .Select(x => string.Join("",x));
    }
}

我把它提升到了另一个层次。扔掉是一个简单的句子,但在我的情况下,我需要整个单词。我想我应该把它发布出来,以防有人需要类似的东西。

static IEnumerable<string> Split(string orgString, int chunkSize, bool wholeWords = true)
{
    if (wholeWords)
    {
        List<string> result = new List<string>();
        StringBuilder sb = new StringBuilder();

        if (orgString.Length > chunkSize)
        {
            string[] newSplit = orgString.Split(' ');
            foreach (string str in newSplit)
            {
                if (sb.Length != 0)
                    sb.Append(" ");

                if (sb.Length + str.Length > chunkSize)
                {
                    result.Add(sb.ToString());
                    sb.Clear();
                }

                sb.Append(str);
            }

            result.Add(sb.ToString());
        }
        else
            result.Add(orgString);

        return result;
    }
    else
        return new List<string>(Regex.Split(orgString, @"(?<=\G.{" + chunkSize + "})", RegexOptions.Singleline));
}

基于以下评论的结果:

string msg = "336699AABBCCDDEEFF";
foreach (string newMsg in Split(msg, 2, false))
{
    Console.WriteLine($">>{newMsg}<<");
}

Console.ReadKey();

结果:

>>33<<
>>66<<
>>99<<
>>AA<<
>>BB<<
>>CC<<
>>DD<<
>>EE<<
>>FF<<
>><<

另一种说法是:

List<string> splitData = (List<string>)Split(msg, 2, false);

for (int i = 0; i < splitData.Count - 1; i++)
{
    Console.WriteLine($">>{splitData[i]}<<");
}

Console.ReadKey();

新结果:

>>33<<
>>66<<
>>99<<
>>AA<<
>>BB<<
>>CC<<
>>DD<<
>>EE<<
>>FF<<