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
在多芬和康他汀的答案组合中……
static IEnumerable<string> WholeChunks(string str, int chunkSize) {
for (int i = 0; i < str.Length; i += chunkSize)
yield return str.Substring(i, chunkSize);
}
这将适用于所有可以被分割成大量块的字符串,否则将抛出异常。
如果你想支持任意长度的字符串,你可以使用下面的代码:
static IEnumerable<string> ChunksUpto(string str, int maxChunkSize) {
for (int i = 0; i < str.Length; i += maxChunkSize)
yield return str.Substring(i, Math.Min(maxChunkSize, str.Length-i));
}
然而,OP明确表示他不需要这个;它有点长,很难读,稍微慢一点。本着KISS和YAGNI的精神,我选择第一个选项:它可能是最有效的实现,而且非常简短、可读,而且重要的是,它会对不符合规范的输入抛出异常。
其他回答
for (int i = 0; i <= Convert.ToInt32(Math.Truncate(Convert.ToDecimal(_string.Length / _chunkSize))); i++)
{
var _currentChunk = _string.Substring(i * _chunkSize, Math.Min(_chunkSize, _string.Length - i * _chunkSize));
//do something with current chunk
}
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<<
public static List<string> DevideByStringLength(string text, int chunkSize)
{
double a = (double)text.Length / chunkSize;
var numberOfChunks = Math.Ceiling(a);
Console.WriteLine($"{text.Length} | {numberOfChunks}");
List<string> chunkList = new List<string>();
for (int i = 0; i < numberOfChunks; i++)
{
string subString = string.Empty;
if (i == (numberOfChunks - 1))
{
subString = text.Substring(chunkSize * i, text.Length - chunkSize * i);
chunkList.Add(subString);
continue;
}
subString = text.Substring(chunkSize * i, chunkSize);
chunkList.Add(subString);
}
return chunkList;
}
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
这也可以用这种方式来完成
string actualString = "1111222233334444";
var listResult = new List<string>();
int groupingLength = actualString.Length % 4;
if (groupingLength > 0)
listResult.Add(actualString.Substring(0, groupingLength));
for (int i = groupingLength; i < actualString.Length; i += 4)
{
listResult.Add(actualString.Substring(i, 4));
}
foreach(var res in listResult)
{
Console.WriteLine(res);
}
Console.Read();