C++Builder 也有StringBuilder

    std::auto_ptr<TStringBuilder> sb(new TStringBuilder());

void __fastcall TMainForm::btReadClick(TObject *Sender)

{

  Char Ch;

  TStringReader* Reader1;

  TStringReader* Reader2;

  TCharArray Buffer;

  String Line;

  String Init;

  Init = String("This is the first line") + char() + "This is the some text";

  /* Create a string reader. */

  Reader1 = new TStringReader(Init);

  Reader2 = new TStringReader(Init);

  /* Read the first string. */

  Edit1->Text = Reader1->ReadLine();

  Memo1->Text = Reader1->ReadToEnd();

  /* Prepare a buffer. */

  Buffer.set_length();

  /* Read first 23 characters from the second string. */

  if (Reader2->ReadBlock(Buffer,,Buffer.Length) < Buffer.Length)

  {

    MessageDlg("Reading failed! Expected to read 23 characters!",

      mtError, TMsgDlgButtons() << mbOK, );

  }

  /* Read the rest of the second string, char-by-char, and write it in the

     second memo box. */

  Line = "";

  do

  {

      Ch = Char(Reader2->Read());

      Line += Ch;

  }

  while (Reader2->Peek() >= );

  Memo2->Text = Line;

  /* Close the reader. */

  Reader1->Close();

  Reader2->Close();

}

//---------------------------------------------------------------------------

void __fastcall TMainForm::btWriteClick(TObject *Sender)

{

  TStringWriter* Writer;

  String MyStr;

  /* Create a string writer. */

  Writer = new TStringWriter();

  /* Store the text in the writer. */

  Writer->WriteLine(Edit1->Text);

  Writer->Write(Memo1->Text + sLineBreak + Memo2->Text);

  MyStr = Writer->ToString();

  ShowMessage(MyStr);

  /* Clear writer's buffer data. */

  Writer->Flush();

  /* Close the writer. */

  Writer->Close();

  delete Writer;

}