base64

uses jpeg,EncdDecd,ZLibEx

//字符串base64 编码
Function StrtoBase64(const Str:string):string;
begin
 result:=EncodeString(Str);
end;
//字符串base64  解码
Function Base64toStr(const Base64:string):string;
begin
 result:=DecodeString(base64);
end;
//Jpeg base64  编码
Function JpegToBase64(Jpeg : Tjpegimage):string;
var
  jpegstream : TMemoryStream;
  StrStream  : TStringStream;
begin
  jpegstream :=TMemoryStream.Create;
  StrStream  :=TStringStream.Create('');
  jpeg.SaveToStream(jpegstream);
  jpegstream.Position:=0;
  EncodeStream(Jpegstream,strstream);
  result:=strstream.DataString;
  jpegstream.Free;
  strstream.Free;
end;
//Jpeg base64  解码
Function Base64ToJpeg(str: string):TJpegimage;
var
  jpegstream : TMemoryStream;
  StrStream  : TStringStream;
begin
  jpegstream :=TMemoryStream.Create;
  StrStream  :=TStringStream.Create(str);
  DecodeStream(StrStream,JpegStream);
  JpegStream.Position:=0;
  result:=TJpegimage.Create;
  result.LoadFromStream(JpegStream);
  jpegstream.Free;
  strstream.Free;
 
end;

///将Bitmap位图转化为base64字符串
function BitmapToString(img:TBitmap):string ;
var
  ms:TMemoryStream;
  ss:TStringStream;
  s:string;
begin
    ms := TMemoryStream.Create;
    img.SaveToStream(ms);
    ss := TStringStream.Create('');
    ms.Position:=0;
    EncodeStream(ms,ss);//将内存流编码为base64字符流
    s:=ss.DataString;
    ms.Free;
    ss.Free;
    result:=s; 
end;

///将base64字符串转化为Bitmap位图
function StringToBitmap(imgStr:string):TBitmap;
var ss:TStringStream;
    ms:TMemoryStream;
    bitmap:TBitmap;
begin
    ss := TStringStream.Create(imgStr);
    ms := TMemoryStream.Create;
    DecodeStream(ss,ms);//将base64字符流还原为内存流
    ms.Position:=0;
    bitmap := TBitmap.Create;
    bitmap.LoadFromStream(ms);
    ss.Free;
    ms.Free;
    result :=bitmap;
end;

function CompressStrToBase64(sStr: string): string;
var
  M1: TMemoryStream;
  M0, M2: TStringStream;
begin
  Result := '';
  if sStr = '' then
    Exit;
  M0 := TStringStream.Create(sStr);
  M1 := TMemoryStream.Create;
  M2 := TStringStream.Create(' ');
  try
    M0.Position := 0;
    M1.Position := 0;
    ZCompressStream(M0, M1);
    M1.Position := 0;
    M2.Position := 0;
    EncodeStream(M1, M2);
    Result := M2.DataString;
  finally
    FreeAndNil(M0);
    FreeAndNil(M1);
    FreeAndNil(M2);
  end;
end;

function DeCompressBase64ToStr(sStr: string): string;
var
  M0, M1: TStringStream;
  M2: TMemoryStream;
begin
  Result := '';
  if sStr = '' then
    Exit;
  M0 := TStringStream.Create;
  M1 := TStringStream.Create(sStr);
  M2 := TMemoryStream.Create;
  try
    M1.Position := 0;
    M2.Position := 0;
    DeCodeStream(M1, M2);
    M0.Position := 0;
    M2.Position := 0;
    ZDecompressStream(M2, M0);
    Result := M0.DataString;
  finally
    FreeAndNil(M0);
    FreeAndNil(M2);
    FreeAndNil(M1);
  end;
end;