delphi将图片转换成文本支持转换回去

以 JPEG 图片为例，以下代码演示了如何将一个 JPEG 图片保存为纯文本形式，并将其以图片形式读回并显示。

保存 TXT：
function TForm1.JpegToText(AFileName:string; SaveFile: Boolean; TxtFileName: string): string;
var
FileStream : TFileStream;
StringStream : TStringStream;
FSize : integer;
FileData : string;
i : integer;
DataStr : string;
begin
try
FileStream := TFileStream.Create(OpenDialog1.FileName, fmOpenRead);
StringStream := TStringStream.Create(EmptyStr);
FSize := FileStream.Size;
StringStream.CopyFrom(FileStream, FSize);
FileData := StringStream.DataString;
DataStr := EmptyStr;
for i := 1 to Length(FileData) do
begin
DataStr := DataStr + InttoHex(Ord(FileData[i]), 2);
end;
Result := DataStr;
if SaveFile then
begin
with TStringList.Create do
begin
Text := DataStr;
SaveToFile(TxtFileName);
Free;
end;
end;
finally
freeandnil(FileStream);
freeandnil(StringStream);
end;
end;

从 TXT 读回 JPEG：
function TForm1.TextToJpeg(AFileName: string; SaveFile: Boolean; JpegFileName: string): TJPEGImage;
var
buf : array of Byte;
DataLength : Integer;
i : Integer;
DataStr : string;
ByteFile : file of byte;
jpg : TJPEGImage;
tmpFileName: string;
begin
with TStringList.Create do
begin
LoadFromFile(AFileName);
DataStr := Text;
Free;
end;
DataLength := Length(DataStr) div 2-1;
SetLength(buf, DataLength);
for i := 1 to DataLength do
begin
buf[i - 1] := StrToInt('$' + copy(DataStr, (i - 1) * 2 + 1, 2));
end;
tmpFileName := ExtractFilePath(ParamStr(0))+'tmp.jpg';
AssignFile(ByteFile, tmpFileName);
Rewrite(ByteFile);
for i := 0 to DataLength - 1 do
begin
write(ByteFile, buf[i]);
end;
CloseFile(ByteFile);
Result := TJPEGImage.Create;
Result.LoadFromFile(tmpFileName);
if SaveFile then
Result.SaveToFile(JpegFileName);
DeleteFile(tmpFileName);
end;