16进制字符串与图片互转

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Button2: TButton;
    Memo1: TMemo;
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

uses pngimage;

{ 从 png 图片到十六进制字符串 }
function Png2Hex(png: TPngImage): string;
var
  stream: TMemoryStream;
begin
  stream := TMemoryStream.Create;
  png.SaveToStream(stream);
  SetLength(Result, stream.Size * 2);
  BinToHex(stream.Memory, PChar(Result), stream.Size);
  stream.Free;
end;

{ 从十六进制字符串恢复 png 图片 }
procedure Hex2Png(str: string; out png: TPngImage);
var
  stream: TMemoryStream;
begin
  if not Assigned(png) then
    png := TPngImage.Create;
  stream := TMemoryStream.Create;
  stream.SetSize(Length(str) div 2);
  HexToBin(PChar(str), stream.Memory, stream.Size);
  png.LoadFromStream(stream);
  stream.Free;
end;

{ 测试 }
procedure TForm1.Button1Click(Sender: TObject);
var
  png: TPngImage;
begin
  png := TPngImage.Create;
  png.LoadFromFile('c:\test.png');
  Memo1.Text := Png2Hex(png);
  png.Free;
end;

procedure TForm1.Button2Click(Sender: TObject);
var
  png: TPngImage;
begin
  png := TPngImage.Create;
  Hex2Png(Memo1.Text, png);
  Canvas.Draw(0, 0, png);
  png.Free;
end;

end.

 

object Form1: TForm1
  Left = 0
  Top = 0
  Caption = 'Form1'
  ClientHeight = 254
  ClientWidth = 480
  Color = clBtnFace
  Font.Charset = DEFAULT_CHARSET
  Font.Color = clWindowText
  Font.Height = -11
  Font.Name = 'Tahoma'
  Font.Style = []
  OldCreateOrder = False
  PixelsPerInch = 96
  TextHeight = 13
  object Button1: TButton
    Left = 64
    Top = 208
    Width = 75
    Height = 25
    Caption = 'Button1'
    TabOrder = 1
    OnClick = Button1Click
  end
  object Button2: TButton
    Left = 200
    Top = 208
    Width = 75
    Height = 25
    Caption = 'Button2'
    TabOrder = 2
    OnClick = Button2Click
  end
  object Memo1: TMemo
    Left = 8
    Top = 8
    Width = 449
    Height = 177
    Lines.Strings = (
      'Memo1')
    TabOrder = 0
  end
end