所以我最终创建了自己的 BigStringBuilder 函数。这是一个列表，其中每个列表元素（或页面）都是一个字符数组（类型为List<char[]>）。
如果您使用的是 64 位 Windows，您现在可以轻松超过 20 亿个字符元素的限制。我设法创建了一个大约 32 GB 的巨型字符串（需要首先增加操作系统中的虚拟内存，否则我只能在我的 8 GB RAM PC 上获得大约 7 GB）。我确信它可以轻松处理超过 32GB 的容量。理论上，它应该能够处理大约 1,000,000,000 * 1,000,000,000 个字符或一个 quintillion 字符，这对任何人来说都应该足够了。
在速度方面，一些快速测试表明它在追加时仅比 StringBuilder 慢 33% 左右。如果我使用 2D 锯齿状字符数组 (char[][]) 而不是 List<char[]>，我会获得非常相似的性能，但列表更易于使用，所以我坚持使用。
希望其他人觉得它有用！可能存在错误，因此请谨慎使用。不过我测试得很好。
// A simplified version specially for StackOverflow
public class BigStringBuilder
{
List<char[]> c = new List<char[]>();
private int pagedepth;
private long pagesize;
private long mpagesize; // https://stackoverflow.com/questions/11040646/faster-modulus-in-c-c
private int currentPage = 0;
private int currentPosInPage = 0;
public BigStringBuilder(int pagedepth = 12) { // pagesize is 2^pagedepth (since must be a power of 2 for a fast indexer)
this.pagedepth = pagedepth;
pagesize = (long)Math.Pow(2, pagedepth);
mpagesize = pagesize - 1;
c.Add(new char[pagesize]);
}
// Indexer for this class, so you can use convenient square bracket indexing to address char elements within the array!!
public char this[long n] {
get { return c[(int)(n >> pagedepth)][n & mpagesize]; }
set { c[(int)(n >> pagedepth)][n & mpagesize] = value; }
}
public string[] returnPagesForTestingPurposes() {
string[] s = new string[currentPage + 1];
for (int i = 0; i < currentPage + 1; i++) s[i] = new string(c[i]);
return s;
}
public void clear() {
c = new List<char[]>();
c.Add(new char[pagesize]);
currentPage = 0;
currentPosInPage = 0;
}
public void fileOpen(string path)
{
clear();
StreamReader sw = new StreamReader(path);
int len = 0;
while ((len = sw.ReadBlock(c[currentPage], 0, (int)pagesize)) != 0) {
if (!sw.EndOfStream) {
currentPage++;
if (currentPage > (c.Count - 1)) c.Add(new char[pagesize]);
}
else {
currentPosInPage = len;
break;
}
}
sw.Close();
}
// See: https://stackoverflow.com/questions/373365/how-do-i-write-out-a-text-file-in-c-sharp-with-a-code-page-other-than-utf-8/373372
public void fileSave(string path) {
StreamWriter sw = File.CreateText(path);
for (int i = 0; i < currentPage; i++) sw.Write(new string(c[i]));
sw.Write(new string(c[currentPage], 0, currentPosInPage));
sw.Close();
}
public long length() {
return (long)currentPage * (long)pagesize + (long)currentPosInPage;
}
public string ToString(long max = 2000000000) {
if (length() < max) return substring(0, length());
else return substring(0, max);
}
public string substring(long x, long y) {
StringBuilder sb = new StringBuilder();
for (long n = x; n < y; n++) sb.Append(c[(int)(n >> pagedepth)][n & mpagesize]); //8s
return sb.ToString();
}
public bool match(string find, long start = 0) {
//if (s.Length > length()) return false;
for (int i = 0; i < find.Length; i++) if (i + start == find.Length || this[start + i] != find[i]) return false;
return true;
}
public void replace(string s, long pos) {
for (int i = 0; i < s.Length; i++) {
c[(int)(pos >> pagedepth)][pos & mpagesize] = s[i];
pos++;
}
}
public void Append(string s)
{
for (int i = 0; i < s.Length; i++)
{
c[currentPage][currentPosInPage] = s[i];
currentPosInPage++;
if (currentPosInPage == pagesize)
{
currentPosInPage = 0;
currentPage++;
if (currentPage == c.Count) c.Add(new char[pagesize]);
}
}
}
}