global.pas

Delphi插件程序示例

unit Global;

interface

uses
  Windows, SysUtils, Classes, Forms, Dialogs;
type
  TPlugIn = class(TObject)
    PlugInID: string;
    PlugInName: string;
    PlugInFile: string;
  end;
  TProc = procedure(); stdcall;
  TAddInsFactory = procedure(var PlugInInfo: Pchar);stdcall;
  TShowForm = function (MainForm:TForm):TForm;stdcall;


procedure LoadPlugIns();                //装载插件集
procedure LoadPlugIn(sr:TSearchRec);    //装载插件
procedure RunPlugIn(PlugInFileName:string); //运行插件
procedure ShowFormToPanel();

var
  lstPlugIn: TList;               //先用lstPlugIn的目的是为了方便以后更改主界面时不用修改插件
  PlugIn: TPlugIn;
  ShowForm : TShowForm;
  CloseForm : TProc;
  i: integer;
  tmpForm:TForm;
implementation
uses MainFrm;

procedure LoadPlugIns();
var
  sr:     TSearchRec;
  Path:   string;
  Found: Integer;
  cPLUGIN_MASK :string;
begin
  cPLUGIN_MASK := '*.dll';         //以扩展名dll为插件后缀
  Path := ExtractFilePath(Application.Exename) + '\AddIns\' ;   //插件存放的目录
   try
    Found := FindFirst(path + cPLUGIN_MASK, 0, sr);
     while Found = 0 do begin
      LoadPlugin(sr);
      Found := FindNext(sr);
     end;
   finally
    FindClose(sr);
   end;
end;


procedure LoadPlugIn(sr: TSearchRec);
var
  LibHandle:     Integer;
  AddInsFactory: TAddInsFactory;
  FileName: string;
  PlugInName: Pchar;
  Describe: Pchar;
  StatType: Pchar;
begin
  FileName := ExtractFilePath(Application.Exename) + 'AddIns\' + sr.Name;
  LibHandle := LoadLibrary(PChar(FileName));
   if LibHandle <> 0 then
   begin
    PlugIn := TPlugIn.Create;
    inc(i);
    PlugIn.PlugInID := inttostr(i);
    PlugIn.PlugInFile := sr.Name;
    AddInsFactory := GetProcAddress(LibHandle,PChar('PlugInName'));
    if Assigned(AddInsFactory) then
      begin
        AddInsFactory(PlugInName);
        PlugIn.PlugInName := PlugInName;
      end;
    lstPlugIn.Add(Pchar(PlugIn));
   end;
   {释放}
  AddInsFactory := nil;
  FreeLibrary(LibHandle);
end;

procedure RunPlugIn(PlugInFileName:string);
var
  LibH:     Integer;
  RunPlugIn: TProc;
  FileName: string;
begin
  FileName := ExtractFilePath(Application.Exename) + 'AddIns\' + PlugInFileName;
  LibH := LoadLibrary(PChar(FileName));
  if LibH <> 0 then
  begin
     ShowForm := GetProcAddress(LibH,PChar('ShowForm'));
     CloseForm := GetProcAddress(LibH,PChar('CloseForm'));
     if Assigned(ShowForm) then
       ShowFormToPanel();
    end;
end;

procedure ShowFormToPanel();
var
  H:THandle;
  R : TRect;
begin
  if Assigned(ShowForm) then
    with MainForm do begin
      tmpForm:=ShowForm(MainForm);
      H := pnlStat.Handle;
      tmpForm.ParentWindow := H;
      GetWindowRect(H, R);
      OffsetRect(R, -R.Left, -R.Top);
      tmpForm.BoundsRect := R;
      tmpForm.Show;
    end;
end;

initialization
  lstPlugIn := TList.Create;
  i := 0;
  
finalization
  while lstPlugIn.Count<>0 do
  begin
    PlugIn := lstPlugIn.Items[0];
    PlugIn.Free;
    lstPlugIn.Delete(0);
  end;
  lstPlugIn.Free;
end.