How can I display the RunFile dialog?

Applies To: C++Builder 1 or higher
Category: Knowledge Base

 

1.

  Start a new application.

 

2.

  Insert in your source code:

 

typedef void (__stdcall *pRunFileDlg)(HWND, HICON,

    LPCSTR, LPCSTR, LPCSTR, UINT);

 

HINSTANCE hInstance;

pRunFileDlg RunFileDlg;

 

typedef struct {

    NMHDR hdr;

    LPCSTR lpFile;

    LPCSTR lpDirectory;

    int nShow;

} NM_RUNFILEDLG;

 

3.

  Edit the OnCreate event of your form:

 

void __fastcall TForm1::FormCreate(TObject *Sender)

{

    hInstance = LoadLibrary("SHELL32.DLL");

    if(!hInstance)

    {

        ShowMessage("Error loading SHELL32.DLL\n"

                    "This application will be closed");

        Application->Terminate();

    }

 

    RunFileDlg = (pRunFileDlg)

        GetProcAddress(hInstance, (char *)61);

}

 

4.

  Edit the OnDestroy event of your form:

 

void __fastcall TForm1::FormDestroy(TObject *Sender)

{

    FreeLibrary(hInstance);

}

 

5.

  Open your header file and insert:

 

private:

    MESSAGE void __fastcall WMNotify(TMessage &);

    BEGIN_MESSAGE_MAP

        MESSAGE_HANDLER(WM_NOTIFY, TMessage,

        WMNotify);

    END_MESSAGE_MAP(TForm);

 

6.

  Insert in your source code:

 

void __fastcall TForm1::WMNotify(TMessage &Message)

{

    NMHDR *Notification = (NMHDR*)Message.LParam;

    if(Notification->code == -510)

    {

        NM_RUNFILEDLG* RunFile = (NM_RUNFILEDLG*)

            Message.LParam;

        ShowMessage("The following application about "

        "to be started:\n" + String(RunFile->lpFile));

    }

    TForm::Dispatch(&Message);

}

 

7.

  Add a Button. Edit its OnClick event:

 

void __fastcall TForm1::Button1Click(TObject *Sender)

{

    RunFileDlg(Handle, NULL, NULL, "RunFile Dialog",

        "This is a simple RunFile dialog example. "

        "Please select a file to be opened:", NULL);

}

 

RunFileDlg is an undocumented function that allows you to show the RunFile dialog. (For more information on undocumented functions, read Undocumented Windows Functions).

 

The RunFileDlg function is dynamically loaded from SHELL32.DLL and executed when Button1 is pressed. Once the user has selected a file to open, Windows sends a WM_NOTIFY message to your main form.

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Copyright © Yoto Yotov