我需要在旧版的Delphi 2007中将字节数组编码为base64字符串(同时解码此字符串)。
更多信息:
我尝试过使用synapse库(正如在Binary to Base64 (Delphi)中所建议的那样)。
我需要在旧版的Delphi 2007中将字节数组编码为base64字符串(同时解码此字符串)。
更多信息:
我尝试过使用synapse库(正如在Binary to Base64 (Delphi)中所建议的那样)。
Indy随Delphi一起发布,具有处理base64的TIdEncoderMIME
和TIdDecoderMIME
类。例如:
uses
..., IdCoder, IdCoderMIME;
var
Bytes: TIdBytes;
Base64String: String;
begin
//...
Bytes := ...; // array of bytes
//...
Base64String := TIdEncoderMIME.EncodeBytes(Bytes);
//...
Bytes := TIdDecoderMIME.DecodeBytes(Base64String);
//...
end;
此外,还有一些编码/解码String
和TStream
数据的方法。
更新:或者,如果你的版本没有上述class
方法:
// TBytesStream was added in D2009, so define it manually for D2007
uses
..., IdCoder, IdCoderMIME
{$IF RTLVersion < 20)
, RTLConsts
{$IFEND}
;
{$IF RTLVersion < 20)
type
TBytesStream = class(TMemoryStream)
private
FBytes: TBytes;
protected
function Realloc(var NewCapacity: Longint): Pointer; override;
public
constructor Create(const ABytes: TBytes); overload;
property Bytes: TBytes read FBytes;
end;
constructor TBytesStream.Create(const ABytes: TBytes);
begin
inherited Create;
FBytes := ABytes;
SetPointer(Pointer(FBytes), Length(FBytes));
FCapacity := FSize;
end;
const
MemoryDelta = $2000; // Must be a power of 2
function TBytesStream.Realloc(var NewCapacity: Integer): Pointer;
begin
if (NewCapacity > 0) and (NewCapacity <> FSize) then
NewCapacity := (NewCapacity + (MemoryDelta - 1)) and not (MemoryDelta - 1);
Result := Pointer(FBytes);
if NewCapacity <> FCapacity then
begin
SetLength(FBytes, NewCapacity);
Result := Pointer(FBytes);
if NewCapacity = 0 then
Exit;
if Result = nil then raise EStreamError.CreateRes(@SMemoryStreamError);
end;
end;
{$IFEND}
var
Bytes: TBytes;
BStrm: TBytesStream;
Encoder: TIdEncoderMIME;
Decoder: TIdDecoderMIME;
Base64String: String;
begin
//...
Bytes := ...; // array of bytes
//...
BStrm := TBytesStream.Create(Bytes);
try
Encoder := TIdEncoderMIME.Create;
try
Base64String := Encoder.Encode(BStrm);
finally
Encoder.Free;
end;
finally
BStrm.Free;
end;
//...
BStrm := TBytesStream.Create;
try
Decoder := TIdDecoderMIME.Create;
try
Decoder.DecodeBegin(BStrm);
Decoder.Decode(Base64String);
Decoder.DecodeEnd;
finally
Decoder.Free;
end;
Bytes := BStrm.Bytes;
finally
BStrm.Free;
end;
//...
end;
IdCoder
单元,了解该版本实际可用的函数。最坏的情况是,class
方法可能不可用,因此尝试实例化TIdEncoderMIME
/TIdDecoderMIME
对象,并使用它们的非class
方法。我在答案中更新了一个示例。 - Remy LebeauTBytesStream
是在D2009中添加的。我已经更新了我的答案,包括D2007的实现。或者,您可以将字节简单地复制到标准的TMemoryStream
中。 - Remy LebeauEncdDecd
单元已包含在Delphi 2007中。您可以直接使用它。David Heffernan做出了很好的回答!
在您的用途中添加“EncdDecd”类,它将具有以下过程:
function DecodeString (const Input: string): string;
function DecodeBase64 (const Input: string): TBytes;
使用https://www.base64encode.org/进行测试
在Delphi和该网站中,“Working”字符串的结果均为:“V29ya2luZw==”
ShowMessage ('Working =' + EncodeString ('Working'));
ShowMessage ('Working =' + DecodeString ('V29ya2luZw =='));
对于旧版本的 Delphi(Delphi XE7 之前),请使用以下方法:
uses
Soap.EncdDecd
procedure DecodeFile(const Base64: AnsiString; const FileName: string);
var
BStream: TBytesStream;
begin
BStream := TBytesStream.Create(DecodeBase64(Base64));
try
BStream.SaveToFile(Filename);
finally
BStream.Free;
end;
end;
uses
System.NetEncoding;
procedure DecodeFile(const Base64: String; const FileName: string);
var
BStream: TBytesStream;
begin
BStream:= TBytesStream.Create(TNetEncoding.Base64.DecodeStringToBytes(Base64));
try
BStream.SaveToFile(Filename);
finally
BStream.Free;
end;
end;
uses
classes, sysutils;
function EncodeToBase64(var Buffer: TBytes): Longint;
const
EncodingTable: PChar = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
var
WriteBuf: array[0..3] of Byte;
Buf: array[0..2] of Byte;
Dest: TMemoryStream;
i, j, Count: Integer;
begin
Result := 0;
Count := Length(Buffer);
j := Count div 3;
if j > 0 then
begin
Dest:= TMemoryStream.Create();
try
Dest.Position := 0;
for i := 0 to j - 1 do
begin
Move(Buffer[i * 3], Buf[0], 3);
WriteBuf[0] := Ord(EncodingTable[Buf[0] shr 2]);
WriteBuf[1] := Ord(EncodingTable[(Buf[0] and 3) shl 4 or (Buf[1] shr 4)]);
WriteBuf[2] := Ord(EncodingTable[(Buf[1] and 15) shl 2 or (Buf[2] shr 6)]);
WriteBuf[3] := Ord(EncodingTable[Buf[2] and 63]);
Dest.Write(WriteBuf, 4);
Inc(Result, 4);
Dec(Count, 3);
end;
if Count in [1, 2] then
begin
Move(Buffer[i * 3], Buf[0], Count);
WriteBuf[0] := Ord(EncodingTable[Buf[0] shr 2]);
WriteBuf[1] := Ord(EncodingTable[(Buf[0] and 3) shl 4 or (Buf[1] shr 4)]);
if Count = 1 then
WriteBuf[2] := Ord('=')
else
WriteBuf[2] := Ord(EncodingTable[(Buf[1] and 15) shl 2 or (Buf[2] shr 6)]);
WriteBuf[3] := Ord('=');
Dest.Write(WriteBuf, 4);
Inc(Result, 4);
Dec(Count, Count);
end;
if Result > 0 then
begin
SetLength(Buffer, Result);
Dest.Position := 0;
Dest.Read(Buffer[0], Result);
end;
finally
Dest.Free;
end;
end;
end;
这应该可以在不需要任何特殊的单位或组件的情况下工作。
TIdDecoderMIME
类。 - RRUZTIdEncoderMIME
- Remy Lebeau