16进制字符串与图片互转

unit Unit1;interfaceuses  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  endend