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"
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
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)
其他回答
稍微更改为返回大小不等于chunkSize的部件
public static IEnumerable<string> Split(this string str, int chunkSize)
{
var splits = new List<string>();
if (str.Length < chunkSize) { chunkSize = str.Length; }
splits.AddRange(Enumerable.Range(0, str.Length / chunkSize).Select(i => str.Substring(i * chunkSize, chunkSize)));
splits.Add(str.Length % chunkSize > 0 ? str.Substring((str.Length / chunkSize) * chunkSize, str.Length - ((str.Length / chunkSize) * chunkSize)) : string.Empty);
return (IEnumerable<string>)splits;
}
我不记得是谁给我的了,但它很好用。我快速测试了几种将枚举类型分成组的方法。用法是这样的…
List<string> Divided = Source3.Chunk(24).Select(Piece => string.Concat<char>(Piece)).ToList();
扩展代码看起来像这样…
#region Chunk Logic
private class ChunkedEnumerable<T> : IEnumerable<T>
{
class ChildEnumerator : IEnumerator<T>
{
ChunkedEnumerable<T> parent;
int position;
bool done = false;
T current;
public ChildEnumerator(ChunkedEnumerable<T> parent)
{
this.parent = parent;
position = -1;
parent.wrapper.AddRef();
}
public T Current
{
get
{
if (position == -1 || done)
{
throw new InvalidOperationException();
}
return current;
}
}
public void Dispose()
{
if (!done)
{
done = true;
parent.wrapper.RemoveRef();
}
}
object System.Collections.IEnumerator.Current
{
get { return Current; }
}
public bool MoveNext()
{
position++;
if (position + 1 > parent.chunkSize)
{
done = true;
}
if (!done)
{
done = !parent.wrapper.Get(position + parent.start, out current);
}
return !done;
}
public void Reset()
{
// per http://msdn.microsoft.com/en-us/library/system.collections.ienumerator.reset.aspx
throw new NotSupportedException();
}
}
EnumeratorWrapper<T> wrapper;
int chunkSize;
int start;
public ChunkedEnumerable(EnumeratorWrapper<T> wrapper, int chunkSize, int start)
{
this.wrapper = wrapper;
this.chunkSize = chunkSize;
this.start = start;
}
public IEnumerator<T> GetEnumerator()
{
return new ChildEnumerator(this);
}
System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator()
{
return GetEnumerator();
}
}
private class EnumeratorWrapper<T>
{
public EnumeratorWrapper(IEnumerable<T> source)
{
SourceEumerable = source;
}
IEnumerable<T> SourceEumerable { get; set; }
Enumeration currentEnumeration;
class Enumeration
{
public IEnumerator<T> Source { get; set; }
public int Position { get; set; }
public bool AtEnd { get; set; }
}
public bool Get(int pos, out T item)
{
if (currentEnumeration != null && currentEnumeration.Position > pos)
{
currentEnumeration.Source.Dispose();
currentEnumeration = null;
}
if (currentEnumeration == null)
{
currentEnumeration = new Enumeration { Position = -1, Source = SourceEumerable.GetEnumerator(), AtEnd = false };
}
item = default(T);
if (currentEnumeration.AtEnd)
{
return false;
}
while (currentEnumeration.Position < pos)
{
currentEnumeration.AtEnd = !currentEnumeration.Source.MoveNext();
currentEnumeration.Position++;
if (currentEnumeration.AtEnd)
{
return false;
}
}
item = currentEnumeration.Source.Current;
return true;
}
int refs = 0;
// needed for dispose semantics
public void AddRef()
{
refs++;
}
public void RemoveRef()
{
refs--;
if (refs == 0 && currentEnumeration != null)
{
var copy = currentEnumeration;
currentEnumeration = null;
copy.Source.Dispose();
}
}
}
/// <summary>Speed Checked. Works Great!</summary>
public static IEnumerable<IEnumerable<T>> Chunk<T>(this IEnumerable<T> source, int chunksize)
{
if (chunksize < 1) throw new InvalidOperationException();
var wrapper = new EnumeratorWrapper<T>(source);
int currentPos = 0;
T ignore;
try
{
wrapper.AddRef();
while (wrapper.Get(currentPos, out ignore))
{
yield return new ChunkedEnumerable<T>(wrapper, chunksize, currentPos);
currentPos += chunksize;
}
}
finally
{
wrapper.RemoveRef();
}
}
#endregion
我个人更喜欢我的解决方案:-)
它处理:
是块大小的倍数的字符串长度。 不是块大小倍数的字符串长度。 小于块大小的字符串长度。 NULL和空字符串(抛出异常)。 块大小小于1(引发异常)。
它是作为一个扩展方法实现的,它预先计算将要生成的块的数量。它检查最后一个块,因为如果文本长度不是一个倍数,它需要更短。干净、简短、容易理解……和工作!
public static string[] Split(this string value, int chunkSize)
{
if (string.IsNullOrEmpty(value)) throw new ArgumentException("The string cannot be null.");
if (chunkSize < 1) throw new ArgumentException("The chunk size should be equal or greater than one.");
int remainder;
int divResult = Math.DivRem(value.Length, chunkSize, out remainder);
int numberOfChunks = remainder > 0 ? divResult + 1 : divResult;
var result = new string[numberOfChunks];
int i = 0;
while (i < numberOfChunks - 1)
{
result[i] = value.Substring(i * chunkSize, chunkSize);
i++;
}
int lastChunkSize = remainder > 0 ? remainder : chunkSize;
result[i] = value.Substring(i * chunkSize, lastChunkSize);
return result;
}
从。net 6开始,我们还可以使用Chunk方法:
var result = str
.Chunk(4)
.Select(x => new string(x))
.ToList();
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<<