https://www.jb51.net/article/122802.htm

Delphi 实现软件自动升级的功能

原理简单，在FTP上维护一个Update.ini文件，里面记录着要更新文件的版本号，本地也有一个Update.ini文件，每次启动更新程序时，先从FTP上下载Update.ini文件到本地名字为Update_new.ini，然后比较这两个文件，如果新的版本号大于旧的，或者新的文件在就ini中没有，这些就表示要更新的文件，然后逐一下载。

    本程序名字为AutoUpdate，你生成这个exe，然后和主程序一起打包，创建桌面快捷方式时，指向AutoUpdate，而不是主程序。

    在本地还有一个ini文件，比如叫ftp.ini吧，里面内容是

[coninfo]
main=Project1.exe
param={app}sayyes.pj2 -y bde.txt

main=Project1.exe：是主程序名称，和升级程序在同一目录

param={app}sayyes.pj2 -y bde.txt：这是命令行参数，app为当前路径，在程序中替换掉，传递给主程序（如果需要的话）

update.ini的内容格式如下

[root]
办事处查询.txt=20100519
[dbcard]
sayyes.pj2=20100519
FTP用户密码.txt=20100519

[root]代表根目录，后面的[dbcard]代表子目录，依次类推

unit Main;
 
interface
 
uses
 Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
 Dialogs, StdCtrls, IdHTTP, IdBaseComponent, IdComponent, IdTCPConnection,
 IdTCPClient, IdFTP, ComCtrls, ExtCtrls,IniFiles,ShellAPI, jpeg;
 
type
 TfrmMain = class(TForm)
  IdFTP1: TIdFTP;
  IdHTTP1: TIdHTTP;
  ProgressBar1: TProgressBar;
  GroupBox1: TGroupBox;
  ld_host: TLabeledEdit;
  ld_username: TLabeledEdit;
  ld_psw: TLabeledEdit;
  ld_port: TLabeledEdit;
  Label1: TLabel;
  cb_mode: TComboBox;
  ProgressBar2: TProgressBar;
  Label3: TLabel;
  list_file: TListView;
  Label4: TLabel;
  procedure IdFTP1Work(Sender: TObject; AWorkMode: TWorkMode;
   const AWorkCount: Integer);
  procedure IdFTP1WorkEnd(Sender: TObject; AWorkMode: TWorkMode);
  procedure FormCreate(Sender: TObject); private
  { Private declarations }
  FSize:Integer;
  FPath: string;
  FExePath: string;
  FInitPath: string;
  FIniFile:TIniFile;
  FHandle:HWND;
  FMainExe:string;
  FParam: string;
 
  procedure CheckUpdateList;
  function ConnectFTP:Boolean;
  procedure DownLoadFile;
  procedure LoadIni;
  procedure SaveIni;
 public
  { Public declarations }
 end;
 
var
 frmMain: TfrmMain;
 
implementation
uses
 Flash;
{$R *.dfm}
//下载进度
procedure TfrmMain.IdFTP1Work(Sender: TObject; AWorkMode: TWorkMode;
 const AWorkCount: Integer);
begin
 ProgressBar1.Position := AWorkCount;
 Application.ProcessMessages;
end;
 
procedure TfrmMain.IdFTP1WorkEnd(Sender: TObject; AWorkMode: TWorkMode);
begin
 ProgressBar1.Position := 0;
 ProgressBar2.StepBy(1);
end;
 
procedure TfrmMain.FormCreate(Sender: TObject);
var
 frm: TfrmFlash;
begin
 Self.Visible := False;
 //闪屏，可以不加
 frm := TfrmFlash.Create(nil);
 frm.Show;
 Application.ProcessMessages;
 FExePath := ExtractFilePath(Application.ExeName);
 FIniFile := TIniFile.Create(FExePath+'ftp.ini');
 //加载ini信息，就是主机和端口之类的信息
 LoadIni;
 try
  ConnectFTP;
  CheckUpdateList;
  Self.Visible := True;
  Application.ProcessMessages;
  DownLoadFile;
 finally
  
  FreeAndNil(frm);
  IdFTP1.Quit;
  FParam := StringReplace(FParam,'{app}',FExePath,[rfReplaceAll]);
//更新完毕后，启动主程序，并传入命令行参数
  ShellExecute(Handle,'open',PChar(FExePath+FMainExe),PChar(FParam),nil,SW_NORMAL);
  Application.Terminate;
 end;
end;
 
//检查更新列表
procedure TfrmMain.CheckUpdateList;
var
 oldFile,newFile:TStringList;
 i,ver,index:Integer;
 itemstr,itempath: string;
 item:TListItem;
begin
 oldFile := TStringList.Create;
 newFile := TStringList.Create;
 try
  list_file.Clear;
  //先下载服务器上的update.ini文件，存到本地update_new.ini
  IdFTP1.Get('update.ini',FExePath+'update_new.ini',True);
  if FileExists(FExePath + 'update.ini') = False then Exit;
  oldFile.LoadFromFile(FExePath + 'update.ini');
  newFile.LoadFromFile(FExePath + 'update_new.ini');
  itempath := '';
  //下面开始比较两个list，如果newFile的版本号大于oldFile的版本号或者oldFile中没有的都表示要更新的
  for i := 0 to newFile.Count - 1 do
  begin
   itemstr := newFile.Strings[i];
   if itemstr = '' then Continue;
   if itemstr[1] = '[' then
   begin
    itempath := Copy(itemstr,2,Length(itemstr)-2);
    //如果是根目录
    if itempath = 'root' then
     itempath := '/';
    Continue;
   end;
   itemstr := newFile.Names[i];
   index := oldFile.IndexOfName(itemstr);
   if index = - 1 then
   begin
    item := list_file.Items.Add;
    item.Caption := itemstr;
    item.SubItems.Add(itempath)
   end
   else
   begin
    ver := StrToIntDef(newFile.Values[itemstr],0);
    if ver > StrToIntDef(oldFile.Values[itemstr],0) then
    begin
     item := list_file.Items.Add;
     item.Caption := itemstr;
     item.SubItems.Add(itempath);
    end;
   end;
  end;
  if list_file.Items.Count = 0 then Application.Terminate;
 finally
  oldFile.Free;
  newFile.Free;
 end;
end;
 
function TfrmMain.ConnectFTP: Boolean;
begin
 Result := False;
 try
 IdFTP1.Host := ld_host.Text;
 IdFTP1.Port := StrToIntDef(ld_port.Text,21);
 IdFTP1.Username := ld_username.Text;
 IdFTP1.Password := ld_psw.Text;
 IdFTP1.Connect;
 IdFTP1.Passive := cb_mode.ItemIndex = 1;
 FInitPath := IdFTP1.RetrieveCurrentDir;
 Result := IdFTP1.Connected;
 except
  Result := False;
 end;
end;
 
//下载文件更新
procedure TfrmMain.DownLoadFile;
var
 i:Integer;
 path:string;
 s1,s2:String;
begin
 ProgressBar2.Max := list_file.Items.Count;
 ProgressBar2.Position := 0;
 FIniFile.EraseSection('error');
 for i := 0 to list_file.Items.Count - 1 do
 begin
  Label4.Caption := '正在下载 '+list_file.Items[i].Caption;
  Application.ProcessMessages;
  IdFTP1.ChangeDir(FInitPath);
  path := list_file.Items[i].SubItems.Strings[0];
  if path <>'/' then
  begin
   IdFTP1.ChangeDir(path);
   ForceDirectories(FExePath+path);
   s1 := list_file.Items[i].Caption;
   s2 := FExePath+path+'/'+list_file.Items[i].Caption;
   IdFTP1.Get(s1,s2,True);
  end
  else
  begin
   s1 := list_file.Items[i].Caption;
   s2 := FExePath+'/'+list_file.Items[i].Caption;
   IdFTP1.Get(s1,s2,True);
   //记录失败项
   FIniFile.WriteString('error',list_file.Items[i].Caption,'成功');
  end;
  except
   //记录失败项
   FIniFile.WriteString('error',list_file.Items[i].Caption,'失败');
  end;
 end;
 Label4.Caption := '所有文件更新完毕！';
 DeleteFile(FExePath+'update.ini');
 CopyFile(PChar(FExePath+'update_new.ini'),PChar(FExePath+'update.ini'),False);
end;
 
procedure TfrmMain.LoadIni;
begin
 ld_host.Text := FIniFile.ReadString('coninfo','host','******');
 ld_username.Text := FIniFile.ReadString('coninfo','user','******');
 ld_psw.Text := FIniFile.ReadString('coninfo','psw','******');
 ld_port.Text := FIniFile.ReadString('coninfo','port','21');
 cb_mode.ItemIndex := FIniFile.ReadInteger('coninfo','mode',1);
 FMainExe := FIniFile.ReadString('coninfo','main','Main.exe');
 FParam := FIniFile.ReadString('coninfo','param','');
end;
 
procedure TfrmMain.SaveIni;
begin
 FIniFile.WriteString('coninfo','host',ld_host.Text);
 FIniFile.WriteString('coninfo','user',ld_username.Text);
 FIniFile.WriteString('coninfo','psw',ld_psw.Text);
 FIniFile.WriteString('coninfo','port',ld_port.Text);
 FIniFile.WriteInteger('coninfo','mode',cb_mode.ItemIndex);
end;
 
end.