Unable to invoke the exports function from bpl

I using Delphi XE, i've the following setup:

Both Mydll.dll and Package1.bpl (runtime package) contains Unit3.pas

unit Unit3;

interface

implementation

uses Dialogs;

procedure TestProc(const S: string); stdcall;
begin
  MessageDlg(S, mtInformation, [mbOK], 0);
end;

exports TestProc;

end.

Case 1:

procedure TestProc(const S: string); stdcall; external 'mydll.dll';

procedure TForm1.Button3Click(Sender: TObject);
begin
  TestProc('Button3');
end;

Case 2:

procedure TestProc(const S: string); stdcall; external 'Package1.bpl';

procedure TForm1.Button3Click(Sender: TObject);
begin
  TestProc('Button3');
end;

Case 3:

procedure TForm1.Button3Click(Sender: TObject);
var H: THandle;
    P: procedure(const S: string); stdcall;
begin
  H := LoadPackage('Package1.bpl');
  try
    @P := GetProcAddress(H, PChar('TestProc'));
    if Assigned(P) then
      P('Button3');
  finally
    UnloadPackage(H);
  end;
end;

Case 1 and Case 3 passed but Case 2 will raise Access Violation.

My question as below,

1. Case 2 is not supported?

2. Except the Case 3, is there anyway to invoke the TestProc from Pa开发者_如何学Gockage1.bpl similar as Case1?

---

Yes the case 2 is supported but you must call the LoadPackage function too to load the package in memory.

try this code

procedure TestProc(const S: string); stdcall;  external 'Package1.bpl';


var
  hPackage : Cardinal;

procedure TForm1.Button1Click(Sender: TObject);
begin
   TestProc('Button3');
end;


initialization
  hPackage := LoadPackage('Package1.bpl');
finalization
  if hPackage<>0 then 
  UnloadPackage(hPackage);

---

For case 2, you could also just simply build your project with runtime packages and include Package1 in the list of runtime packages for your project (in Project Options\Packages\Runtime packages). Then you can remove the import (external declaration) and just use the unit which contains the function.