TstringBuilder Delphi2007版

       2010中的StringBuilder对象用的比较爽快！于是稍作了一些修改（增加了几个函数和属性）然后移植到D2007中来使用了！效果不错，共享一下！

        

unit DxStringBuilder;

interface
uses RTLConsts,Classes,SysUtils;
type
  EExternal = class(Exception)
  public
{$IFDEF MSWINDOWS}
    ExceptionRecord: PExceptionRecord platform;
{$ENDIF}
{$IF defined(LINUX) or defined(MACOSX)}
    ExceptionAddress: LongWord platform;
    AccessAddress: LongWord platform;
    SignalNumber: Integer platform;
{$IFEND LINUX or MACOSX}
  end;

  EIntError = class(EExternal);
  ERangeError = class(EIntError);
  TCharArray = array of Char;
  TStringBuilder = class
  private
    const DefaultCapacity = $10;
    function GetCapacity: Integer;
    procedure SetCapacity(const Value: Integer);
    function GetLength: Integer;
    procedure Set_Length(const Value: Integer);
    function GetMaxCapacity: Integer;

    procedure ReduceCapacity;
    procedure ExpandCapacity;
    procedure CheckBounds(Index: Integer);
    function _Replace(Index: Integer; const Old, New: string): Boolean;
    function GetChars(index: Integer): Char;
    procedure SetChars(index: Integer; const Value: Char);
  protected
    FData: TCharArray;
    FLength: Integer;
    FMaxCapacity: Integer;
  public
    constructor Create; overload;
    constructor Create(aCapacity: Integer); overload;
    constructor Create(const Value: string); overload;
    function Append(const Value: Boolean): TStringBuilder; overload;
    function Append(const Value: Byte): TStringBuilder; overload;
    function Append(const Value: Char): TStringBuilder; overload;
    function Append(const Value: Currency): TStringBuilder; overload;
    function Append(const Value: Double): TStringBuilder; overload;
    function Append(const Value: Smallint): TStringBuilder; overload;
    function Append(const Value: Integer): TStringBuilder; overload;
    function Append(const Value: Int64): TStringBuilder; overload;
    function Append(const Value: TObject): TStringBuilder; overload;
    function Append(const Value: Shortint): TStringBuilder; overload;
    function Append(const Value: Single): TStringBuilder; overload;
    function Append(const Value: string): TStringBuilder; overload;
    function Append(const Value: UInt64): TStringBuilder; overload;
    function Append(const Value: TCharArray): TStringBuilder; overload;
    function Append(const Value: Word): TStringBuilder; overload;
    function Append(const Value: Cardinal): TStringBuilder; overload;
    function Append(const Value: Char; RepeatCount: Integer): TStringBuilder; overload;
    function Append(const Value: TCharArray; StartIndex: Integer; CharCount: Integer): TStringBuilder; overload;
    function Append(const Value: string; StartIndex: Integer; Count: Integer): TStringBuilder; overload;

    function AppendFormat(const Format: string; const Args: array of const): TStringBuilder; overload;
    function AppendLine: TStringBuilder; overload;
    function AppendLine(const Value: string): TStringBuilder; overload;

    procedure Clear;
    procedure CopyTo(SourceIndex: Integer; const Destination: TCharArray; DestinationIndex: Integer; Count: Integer);
    function EnsureCapacity(aCapacity: Integer): Integer;
    function Equals(StringBuilder: TStringBuilder): Boolean; reintroduce;

    function Insert(Index: Integer; const Value: Boolean): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: Byte): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: Char): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: Currency): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: Double): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: Smallint): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: Integer): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: TCharArray): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: Int64): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: TObject): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: Shortint): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: Single): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: string): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: Word): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: Cardinal): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: UInt64): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: string; count: Integer): TStringBuilder; overload;
    function Insert(Index: Integer; const Value: TCharArray; startIndex: Integer; charCount: Integer): TStringBuilder; overload;

    function Remove(StartIndex: Integer; RemLength: Integer): TStringBuilder;

    function Replace(const OldChar: Char; const NewChar: Char): TStringBuilder; overload;
    function Replace(const OldValue: string; const NewValue: string): TStringBuilder; overload;
    function Replace(const OldChar: Char; const NewChar: Char; StartIndex: Integer; Count: Integer): TStringBuilder; overload;
    function Replace(const OldValue: string; const NewValue: string; StartIndex: Integer; Count: Integer): TStringBuilder; overload;
    function ToString: string; overload;
    function ToString(StartIndex: Integer; StrLength: Integer): string; reintroduce; overload;

    procedure SaveToStream(Stream: TStream);
    procedure SaveToFile(FileName: string);
    procedure LoadFromStream(Stream: TStream);
    procedure LoadFromFile(FileName: string);

    property Capacity: Integer read GetCapacity write SetCapacity;
    property Chars[index: Integer]: Char read GetChars write SetChars; default;
    property Length: Integer read GetLength write Set_Length;
    property MaxCapacity: Integer read GetMaxCapacity;
  end;


function UIntToStr(Value: Cardinal): string; overload;
function UIntToStr(Value: UInt64): string; overload;

resourcestring
  SParamIsNegative = 'Parameter %s cannot be a negative value';
  SInputBufferExceed = 'Input buffer exceeded for %s = %d, %s = %d';
implementation

function UIntToStr(Value: Cardinal): string;
begin
  FmtStr(Result, '%u', [Value]);
end;

function UIntToStr(Value: UInt64): string;
begin
  FmtStr(Result, '%u', [Value]);
end;

{ TStringBuilder }

constructor TStringBuilder.Create;
begin
  inherited Create;
  FMaxCapacity := MaxInt;
  Capacity := DefaultCapacity;
  FLength := 0;
end;

constructor TStringBuilder.Create(aCapacity: Integer);
begin
  inherited Create;
  FMaxCapacity := MaxInt;
  Capacity := aCapacity;
  FLength := 0;
end;

function TStringBuilder.Append(const Value: string): TStringBuilder;
begin
  Length := Length + System.Length(Value);
  Move(PChar(Value)^, FData[Length - System.Length(Value)], System.Length(Value) * SizeOf(Char));
  Result := self;
end;

function TStringBuilder.Append(const Value: Currency): TStringBuilder;
begin
  Append(CurrToStr(Value));
  Result := Self;
end;

function TStringBuilder.Append(const Value: Double): TStringBuilder;
begin
  Append(FloatToStr(Value));
  Result := Self;
end;

function TStringBuilder.Append(const Value: Char): TStringBuilder;
begin
  Length := Length + 1;
  FData[Length - 1] := Value;
  Result := Self;
end;

function TStringBuilder.Append(const Value: Boolean): TStringBuilder;
begin
  Append(BoolToStr(Value, True));
  Result := Self;
end;

function TStringBuilder.Append(const Value: Byte): TStringBuilder;
begin
  Append(IntToStr(Value));
  Result := Self;
end;

function TStringBuilder.Append(const Value: Smallint): TStringBuilder;
begin
  Append(IntToStr(Value));
  Result := Self;
end;

function TStringBuilder.Append(const Value: Shortint): TStringBuilder;
begin
  Append(IntToStr(Value));
  Result := Self;
end;

function TStringBuilder.Append(const Value: Single): TStringBuilder;
begin
  Append(FloatToStr(Value));
  Result := self;
end;

function TStringBuilder.Append(const Value: TObject): TStringBuilder;
begin
{$if CompilerVersion >= 19}
  Append(Value.ToString());
{$else}
  if Value.InheritsFrom(TComponent) then
    Append(TComponent(Value).Name+': '+Value.ClassName)
  else Append(Value.ClassName);
{$ifend}
  Result := Self;
end;

function TStringBuilder.Append(const Value: Integer): TStringBuilder;
begin
  Append(IntToStr(Value));
  Result := Self;
end;

function TStringBuilder.Append(const Value: Int64): TStringBuilder;
begin
  Append(IntToStr(Value));
  Result := Self;
end;

procedure TStringBuilder.CheckBounds(Index: Integer);
begin
  if Cardinal(Index) >= Cardinal(Length) then
    raise ERangeError.CreateResFmt(@SListIndexError, [Index]);
end;

procedure TStringBuilder.Clear;
begin
  Length := 0;
  Capacity := DefaultCapacity;
end;

procedure TStringBuilder.CopyTo(SourceIndex: Integer;
  const Destination: TCharArray; DestinationIndex, Count: Integer);
begin
  if Count < 0 then
    raise ERangeError.CreateResFmt(@SParamIsNegative, ['Count']); // DO NOT LOCALIZE
  if DestinationIndex < 0 then
    raise ERangeError.CreateResFmt(@SParamIsNegative, ['DestinationIndex']); // DO NOT LOCALIZE
  if DestinationIndex + Count > System.Length(Destination) then
    raise ERangeError.CreateResFmt(@SInputBufferExceed,
      ['DestinationIndex', DestinationIndex, 'Count', Count]);

  if Count > 0 then
  begin
    CheckBounds(SourceIndex);
    CheckBounds(SourceIndex + Count - 1);

    Move(FData[SourceIndex], Destination[DestinationIndex], Count * SizeOf(Char));
  end;
end;

constructor TStringBuilder.Create(const Value: string);
begin
  Create;
  Append(Value);
end;

function TStringBuilder.EnsureCapacity(aCapacity: Integer): Integer;
begin
  if Cardinal(aCapacity) > Cardinal(MaxCapacity) then
    raise ERangeError.CreateResFmt(@SListIndexError, [aCapacity]);

  if Capacity < aCapacity then
    Capacity := aCapacity;

  Result := Capacity;
end;

function TStringBuilder.Equals(StringBuilder: TStringBuilder): Boolean;
begin
  Result := (StringBuilder <> nil) and (Length = StringBuilder.Length) and
    (MaxCapacity = StringBuilder.MaxCapacity) and
    CompareMem(@FData[0], @StringBuilder.FData[0], Length * SizeOf(Char));
end;

procedure TStringBuilder.ExpandCapacity;
var
  NewCapacity: Integer;
begin
  NewCapacity := Capacity * 2;
  if Length > NewCapacity then
    NewCapacity := Length * 2; // this line may overflow NewCapacity to a negative value
  if NewCapacity > MaxCapacity then
    NewCapacity := MaxCapacity;
  if NewCapacity < 0 then // if NewCapacity has been overflowed
    NewCapacity := Length;
  Capacity := NewCapacity;
end;

function TStringBuilder.GetCapacity: Integer;
begin
  Result := System.Length(FData);
end;

function TStringBuilder.GetChars(index: Integer): Char;
begin
  if Index < 0 then
    raise ERangeError.CreateResFmt(@SParamIsNegative, ['Index']); // DO NOT LOCALIZE
  CheckBounds(Index);

  Result := FData[Index];
end;

function TStringBuilder.GetLength: Integer;
begin
  Result := FLength;
end;

function TStringBuilder.GetMaxCapacity: Integer;
begin
  Result := FMaxCapacity;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: Integer): TStringBuilder;
begin
  Insert(Index, IntToStr(Value));
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: Smallint): TStringBuilder;
begin
  Insert(Index, IntToStr(Value));
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: Int64): TStringBuilder;
begin
  Insert(Index, IntToStr(Value));
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: TCharArray): TStringBuilder;
begin
  if Index < 0 then
    raise ERangeError.CreateResFmt(@SParamIsNegative, ['Index']); // DO NOT LOCALIZE
  if Index > Length then
    raise ERangeError.CreateResFmt(@SListIndexError, [Index]);

  Length := Length + System.Length(Value);
  Move(FData[Index], FData[Index + System.Length(Value)], System.Length(Value) * SizeOf(Char));
  Move(Value[0], FData[Index], System.Length(Value) * SizeOf(Char));
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: Double): TStringBuilder;
begin
  Insert(Index, FloatToStr(Value));
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: Byte): TStringBuilder;
begin
  Insert(Index, IntToStr(Value));
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: Boolean): TStringBuilder;
begin
  Insert(Index, BoolToStr(Value, True));
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: Currency): TStringBuilder;
begin
  Insert(Index, CurrToStr(Value));
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: Char): TStringBuilder;
begin
  if Index < 0 then
    raise ERangeError.CreateResFmt(@SParamIsNegative, ['Index']); // DO NOT LOCALIZE
  if Index > Length then
    raise ERangeError.CreateResFmt(@SListIndexError, [Index]);

  Length := Length + 1;
  Move(FData[Index], FData[Index + 1], (Length - Index - 1) * SizeOf(Char));
  FData[Index] := Value;
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: UInt64): TStringBuilder;
begin
  Insert(Index, IntToStr(Value));
  Result := self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: Cardinal): TStringBuilder;
begin
  Insert(Index, IntToStr(Value));
  Result := self;
end;

function TStringBuilder.Insert(Index: Integer; const Value: TCharArray;
  startIndex, charCount: Integer): TStringBuilder;
begin
  if Index - 1 >= Length then
    raise ERangeError.CreateResFmt(@SListIndexError, [Index])
  else if Index < 0 then
    raise ERangeError.CreateResFmt(@SListIndexError, [Index]);
  if StartIndex < 0 then
    raise ERangeError.CreateResFmt(@SParamIsNegative, ['StartIndex']); // DO NOT LOCALIZE
  if CharCount < 0 then
    raise ERangeError.CreateResFmt(@SParamIsNegative, ['CharCount']); // DO NOT LOCALIZE
  if StartIndex + CharCount > System.Length(Value) then
    raise ERangeError.CreateResFmt(@SInputBufferExceed,
      ['StartIndex', StartIndex, 'CharCount', CharCount]);

  Length := Length + CharCount;

  if Length - Index > 0 then
    Move(FData[Index], FData[Index + CharCount], (Length - Index) * SizeOf(Char));
  Move(Value[StartIndex], FData[Index], CharCount * SizeOf(Char));
  Result := Self;
end;

procedure TStringBuilder.LoadFromFile(FileName: string);
var
  F: TFileStream;
begin
  F := TFileStream.Create(FileName,fmOpenRead);
  LoadFromStream(F);
  F.Free;
end;

procedure TStringBuilder.LoadFromStream(Stream: TStream);
begin
  Capacity := Stream.Size;
  Stream.Position := 0;
  Stream.ReadBuffer(FData[0],Stream.Size);
  Length := Stream.Size;
end;

procedure TStringBuilder.ReduceCapacity;
var
  NewCapacity: Integer;
begin
  if Length > Capacity div 4 then
    Exit;

  NewCapacity := Capacity div 2;
  if NewCapacity < Length then
    NewCapacity := Length;
  Capacity := NewCapacity;
end;

function TStringBuilder.Remove(StartIndex, RemLength: Integer): TStringBuilder;
begin
  if RemLength <> 0 then
  begin
    if StartIndex < 0 then
      raise ERangeError.CreateResFmt(@SParamIsNegative, ['StartIndex']); // DO NOT LOCALIZE
    if RemLength < 0 then
      raise ERangeError.CreateResFmt(@SParamIsNegative, ['RemLength']); // DO NOT LOCALIZE
    CheckBounds(StartIndex);
    CheckBounds(StartIndex + RemLength - 1);

    if (Length - (StartIndex + RemLength)) > 0 then
      Move(FData[StartIndex + RemLength], FData[StartIndex], (Length - (StartIndex + RemLength)) * SizeOf(Char));
    Length := Length - RemLength;

    ReduceCapacity;
  end;
  Result := Self;
end;

function TStringBuilder.Replace(const OldValue,
  NewValue: string): TStringBuilder;
begin
  Result := self;
  Replace(OldValue, NewValue, 0, Length);
end;

function TStringBuilder.Replace(const OldChar, NewChar: Char): TStringBuilder;
var
  Ptr: PChar;
  EndPtr: PChar;
begin
  EndPtr := @FData[Length - 1];
  Ptr := @FData[0];
  while Ptr <= EndPtr do
  begin
    if Ptr^ = OldChar then
      Ptr^ := NewChar;
    Inc(Ptr);
  end;
  Result := Self;
end;

function TStringBuilder.Replace(const OldValue, NewValue: string; StartIndex,
  Count: Integer): TStringBuilder;
var
  CurPtr: PChar;
  EndPtr: PChar;
  Index: Integer;
  EndIndex: Integer;
  oldLen, newLen: Integer;
begin
  Result := Self;

  if Count <> 0 then
  begin
    if StartIndex < 0 then
      raise ERangeError.CreateResFmt(@SParamIsNegative, ['StartIndex']); // DO NOT LOCALIZE
    if Count < 0 then
      raise ERangeError.CreateResFmt(@SParamIsNegative, ['Count']); // DO NOT LOCALIZE
    if StartIndex + Count > Length then
      raise ERangeError.CreateResFmt(@SInputBufferExceed,
        ['StartIndex', StartIndex, 'Count', Count]);

    oldLen := System.Length(OldValue);
    newLen := System.Length(NewValue);
    Index := StartIndex;
    CurPtr := @FData[StartIndex];
    EndIndex := StartIndex + Count - oldLen;
    EndPtr := @FData[EndIndex];

    while CurPtr <= EndPtr do
    begin
      if CurPtr^ = OldValue[1] then
      begin
        if StrLComp(CurPtr, PChar(OldValue), oldLen) = 0 then
        begin
          if _Replace(Index, OldValue, NewValue) then
          begin
            CurPtr := @FData[Index];
            EndPtr := @FData[EndIndex];
          end;
          Inc(CurPtr, newLen - 1);
          Inc(Index, newLen - 1);
          Inc(EndPtr, newLen - oldLen);
          Inc(EndIndex, newLen - oldLen);
        end;
      end;

      Inc(CurPtr);
      Inc(Index);
    end;
  end;
end;

function TStringBuilder.Replace(const OldChar, NewChar: Char; StartIndex,
  Count: Integer): TStringBuilder;
var
  Ptr: PChar;
  EndPtr: PChar;
begin
  if Count <> 0 then
  begin
    if StartIndex < 0 then
      raise ERangeError.CreateResFmt(@SParamIsNegative, ['StartIndex']); // DO NOT LOCALIZE
    if Count < 0 then
      raise ERangeError.CreateResFmt(@SParamIsNegative, ['Count']); // DO NOT LOCALIZE
    CheckBounds(StartIndex);
    CheckBounds(StartIndex + Count - 1);

    EndPtr := @FData[StartIndex + Count - 1];
    Ptr := @FData[StartIndex];
    while Ptr <= EndPtr do
    begin
      if Ptr^ = OldChar then
        Ptr^ := NewChar;
      Inc(Ptr);
    end;
  end;
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer; const Value: string;
  count: Integer): TStringBuilder;
var
  I: Integer;
begin
  for I := 0 to Count - 1 do
    Insert(Index, Value);
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: Word): TStringBuilder;
begin
  Insert(Index, IntToStr(Value));
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: Shortint): TStringBuilder;
begin
  Insert(Index, IntToStr(Value));
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: TObject): TStringBuilder;
begin
{$if CompilerVersion >= 19}
  Insert(Index, Value.ToString());
{$else}
  Insert(Index, IntToStr(Integer(Value)));
{$ifend}
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: string): TStringBuilder;
begin
  if Index < 0 then
    raise ERangeError.CreateResFmt(@SParamIsNegative, ['Index']); // DO NOT LOCALIZE
  if Index > Length then
    raise ERangeError.CreateResFmt(@SListIndexError, [Index]);

  Length := Length + System.Length(Value);
  Move(FData[Index], FData[Index + System.Length(Value)], (Length - System.Length(Value) - Index) * SizeOf(Char));
  Move(Value[1], FData[Index], System.Length(Value) * SizeOf(Char));
  Result := Self;
end;

function TStringBuilder.Insert(Index: Integer;
  const Value: Single): TStringBuilder;
begin
  Insert(Index, FloatToStr(Value));
  Result := Self;
end;

procedure TStringBuilder.SaveToFile(FileName: string);
var
  FileStream: TFileStream;
begin
  FileStream := TFileStream.Create(FileName,fmOpenWrite);
  SaveToStream(FileStream);
  FileStream.Free;
end;

procedure TStringBuilder.SaveToStream(Stream: TStream);
begin
  Stream.WriteBuffer(FData[0],Length * SizeOf(Char));
end;

procedure TStringBuilder.SetCapacity(const Value: Integer);
begin
  if Value < Length then
    raise ERangeError.CreateResFmt(@SListCapacityError, [Value]);
  if Value > FMaxCapacity then
    raise ERangeError.CreateResFmt(@SListCapacityError, [Value]);

  SetLength(FData, Value);
end;

procedure TStringBuilder.SetChars(index: Integer; const Value: Char);
begin
  if Index < 0 then
    raise ERangeError.CreateResFmt(@SParamIsNegative, ['Index']); // DO NOT LOCALIZE
  CheckBounds(Index);

  FData[Index] := Value;
end;

procedure TStringBuilder.Set_Length(const Value: Integer);
var
  LOldLength: Integer;
begin
  if Value < 0 then
    raise ERangeError.CreateResFmt(@SParamIsNegative, ['Value']); // DO NOT LOCALIZE
  if Value > MaxCapacity then
    raise ERangeError.CreateResFmt(@SListCapacityError, [Value]);

  LOldLength := FLength;
  try
    FLength := Value;
    if FLength > Capacity then
      ExpandCapacity;
  except
    on E: EOutOfMemory do
      FLength := LOldLength;
  end;
end;

function TStringBuilder.ToString: string;
begin
  SetLength(Result, Length);
  Move(FData[0], Result[1], Length * SizeOf(Char));
end;

function TStringBuilder.ToString(StartIndex, StrLength: Integer): string;
begin
  if StrLength <> 0 then
  begin
    if StartIndex < 0 then
      raise ERangeError.CreateResFmt(@SParamIsNegative, ['StartIndex']); // DO NOT LOCALIZE
    if StrLength < 0 then
      raise ERangeError.CreateResFmt(@SParamIsNegative, ['StrLength']); // DO NOT LOCALIZE
    CheckBounds(StartIndex);
    CheckBounds(StartIndex + StrLength - 1);

    SetLength(Result, StrLength);
    Move(FData[StartIndex], Result[1], StrLength * SizeOf(Char));
  end
  else Result := '';
end;

function TStringBuilder._Replace(Index: Integer; const Old,
  New: string): Boolean;
var
  OldCapacity: Integer;
  SizeChange: Integer;
begin
  Result := False;
  SizeChange := System.Length(New) - System.Length(Old);

  if SizeChange = 0 then
  begin
    Move(New[1], FData[Index], System.Length(New) * SizeOf(Char));
  end
  else
  begin
    if SizeChange > 0 then
    begin
      OldCapacity := Capacity;
      Length := Length + SizeChange;
      if OldCapacity <> Capacity then
        Result := True;
    end;

    Move(FData[Index + System.Length(Old)], FData[Index + System.Length(New)], (Length - (System.Length(Old) + Index)) * SizeOf(Char));
    Move(New[1], FData[Index], System.Length(New) * SizeOf(Char));

    if SizeChange < 0 then
      Length := Length + SizeChange;
  end;
end;

function TStringBuilder.Append(const Value: Word): TStringBuilder;
begin
  Append(IntToStr(Value));
  Result := self;
end;

function TStringBuilder.Append(const Value: TCharArray): TStringBuilder;
var
  I: Integer;
begin
  Result := self;

  for I := 0 to System.Length(Value) - 1 do
    if Value[I] = #0 then
      Break;

  Append(Value, 0, I);
end;

function TStringBuilder.Append(const Value: UInt64): TStringBuilder;
begin
  Append(UIntToStr(Value));
  Result := self;
end;

function TStringBuilder.Append(const Value: Cardinal): TStringBuilder;
begin
  Append(UIntToStr(Value));
  Result := self;
end;

function TStringBuilder.Append(const Value: string; StartIndex,
  Count: Integer): TStringBuilder;
begin
  if StartIndex + Count > System.Length(Value) then
    raise ERangeError.CreateResFmt(@SListIndexError, [StartIndex]);
  if StartIndex < 0 then
    raise ERangeError.CreateResFmt(@SListIndexError, [StartIndex]);

  Length := Length + Count;
  Move(Value[StartIndex + 1], FData[Length - Count], Count * SizeOf(Char));
  Result := Self;
end;

function TStringBuilder.AppendFormat(const Format: string;
  const Args: array of const): TStringBuilder;
begin
  Append(SysUtils.Format(Format, Args));
  Result := Self;
end;

function TStringBuilder.AppendLine: TStringBuilder;
begin
  Append(sLineBreak);
  Result := Self;
end;

function TStringBuilder.AppendLine(const Value: string): TStringBuilder;
begin
  Append(Value);
  AppendLine;
  Result := Self;
end;

function TStringBuilder.Append(const Value: TCharArray; StartIndex,
  CharCount: Integer): TStringBuilder;
begin
  if StartIndex + CharCount > System.Length(Value) then
    raise ERangeError.CreateResFmt(@SListIndexError, [StartIndex]);
  if StartIndex < 0 then
    raise ERangeError.CreateResFmt(@SListIndexError, [StartIndex]);

  Length := Length + CharCount;
  Move(Value[StartIndex], FData[Length - CharCount], CharCount * SizeOf(Char));
  Result := self;
end;

function TStringBuilder.Append(const Value: Char;
  RepeatCount: Integer): TStringBuilder;
begin
  Append(System.StringOfChar(Value, RepeatCount));
  Result := Self;
end;

end.

转自：http://www.cnblogs.com/DxSoft/archive/2010/01/03/1638242.html

http://blog.csdn.net/rznice/article/details/8016565