Re: [Dev-C++] Create DialogBox on demand

[Bruno B. <bbe...@cl...>]

Hi,

The GetOpenFilename function is what your looking for.

BOOL GetOpenFileName(OPENFILNAME lpofn) The GetOpenFileName function
creates a
system-defined dialog box that enables the user to select a file to open.

Parameters

lpofn

Points to an OPENFILENAME structure that contains information used to
initialize
the dialog box. When GetOpenFileName returns, this structure contains
information about the user's file selection.

Return Value

If the user selects a file to open, the return value is TRUE. It is FALSE
if an
error occurs, the user chooses the Cancel button, the user chooses the
Close
command on the System menu to close the dialog box, or the buffer
identified by
the lpstrFile member of the OPENFILENAME structure is too small to contai=
n
the
string that specifies the selected file.

The OPENFILENAME structure contains information the operating system uses
to
initialize the system-defined Open or Save As dialog box. After the user
closes
the dialog box, the system returns information about the user's selection
in
this structure.

Members of OPENFILENAME structure:

lStructSize

Specifies the length, in bytes, of the structure.

hwndOwner

Identifies the window that owns the dialog box. This member can be any
valid
window handle, or it can be NULL if the dialog box has no owner.

hInstance

Identifies a data block that contains a dialog box template specified by
the
lpTemplateName member (if the Flags member is set to OFN_ENABLETEMPLATE).
Identifies the memory object containing a dialog box template (if Flags i=
s
set
to OFN_ENABLETEMPLATEHANDLE). If neither OFN_ENABLETEMPLATE nor
OFN_ENABLETEMPLATEHANDLE is set, this member is ignored.

lpstrFilter

Points to a buffer containing pairs of null-terminated filter strings. Th=
e
first
string in each pair describes a filter (for example, "Text Files"), and t=
he
second specifies the filter pattern (for example, "*.TXT"). Multiple
filters can
be specified for a single item by separating the filter pattern strings
with a
semicolon (for example, "*.TXT;*.DOC;*.BAK"). The last string in the buff=
er
must
be terminated by two NULL characters. If this member is NULL, the dialog
box
will not display any filters. The filter strings are assumed to be in the
proper
order =BE the operating system does not change the order.

lpstrCustomFilter

Points to a buffer containing a pair of user-defined filter strings. The
first
string describes the filter, and the second specifies the filter pattern
(for
example "WinWord, *.docnn"). The buffer is terminated by two NULL
characters.
The operating system copies the strings to the buffer when the user close=
s
the
dialog box. The system uses the strings to initialize the user-defined fi=
le
filter the next time the dialog box is created. If this member is NULL, t=
he
dialog box lists but does not save user-defined filter strings.

Windows 95: If this member is NULL, the member is ignored.
If this member is not NULL, the value of the nMaxCustFilter member is use=
d
to
determine the length of the corresponding string.

nMaxCustFilter

Specifies the size, in bytes or characters, of the buffer identified by
lpstrCustomFilter. This buffer should be at least 40 characters long. Thi=
s
member is ignored if lpstrCustomFilter is NULL or points to a NULL string.
Windows 95: The value of nMaxcustFilter is used whenever lpstrCustomFilte=
r
is
defined.

nFilterIndex

Specifies an index into the buffer pointed to by lpstrFilter. The system
uses
the index value to obtain a pair of strings to use as the initial filter
description and filter pattern for the dialog box. The first pair of
strings has
an index value of 1. When the user closes the dialog box, the system copi=
es
the
index of the selected filter strings into this location. If nFilterIndex =
is
zero, the custom filter is used. If nFilterIndex is zero and
lpstrCustomFilter
is NULL, the system uses the first filter in the buffer identified by
lpstrFilter. If all three members are zero or NULL, the system does not u=
se
any
filters and does not show any files in the file list control of the dialo=
g
box.

lpstrFile

Points to a buffer that contains a filename used to initialize the File
Name
edit control. The first character of this buffer must be NULL if
initialization
is not necessary. When the GetOpenFileName or GetSaveFileName function
returns,
this buffer contains the drive designator, path, filename, and extension =
of
the
selected file.
If the buffer is too small, the dialog box procedure copies the required
size
into this member.

nMaxFile

Windows NT: Specifies the size, in characters, of the buffer pointed to b=
y
lpstrFile. The GetOpenFileName and GetSaveFileName functions return FALSE
if the
buffer is too small to contain the file information. The buffer should be
at
least 256 characters long. This member is ignored if lpstrFile is NULL.
Windows 95: Specifies the size in bytes or characters of the buffer point=
ed
to
by lpstrFile. The buffer should be at least 260 charcters long. this memb=
er
is
ignored if lpstrFile is NULL.

lpstrFileTitle

Points to a buffer that receives the title of the selected file. For
Windows
versions 3.0 and 3.1, this buffer receives the filename and extension
without
path information. The application should use this string to display the
file
title. If this member is NULL, the function does not copy the file title.

nMaxFileTitle

Specifies the maximum length of the string that can be copied into the
lpstrFileTitle buffer. This member is ignored if lpstrFileTitle is NULL.

lpstrInitialDir

Points to a string that specifies the initial file directory. If this
member is
NULL, the system uses the current directory as the initial directory.

lpstrTitle

Points to a string to be placed in the title bar of the dialog box. If th=
is
member is NULL, the system uses the default title (that is, "Save As" or
"Open").

Flags

Specifies the dialog box creation flags. This member may be a combination
of the
following flags:

Flag Meaning
OFN_ALLOWMULTISELECT
Specifies that the File Name list box allows multiple selections. (If the
dialog
box is created by using a private template, the definition of the File Na=
me
list
box must contain the LBS_EXTENDEDSEL value.)Specifies that the File Name
list
box allows multiple selections. If the dialog box is created by using a
private
template, the  definition of the File Name list box must contain the
LBS_EXTENDEDSEL value.When this flag is set, the lpstrFile member points =
to
a
buffer containing the path to the current directory and all filenames in
the
selection. The first filename is separated from the path by a space. Each
subsequent filename is separated by one space from the preceding filename.
Note
that for the new Explorer-style dialogs (dialogs that have the OFN_EXPLOR=
ER
flag
set), a single null character, \0, separates the filenames, and two null
characters, \0\0, terminate the entire string.
OFN_CREATEPROMPT
Specifies that the dialog box function should ask whether the user wants =
to
create a file that does not currently exist. (This flag automatically use=
s
the
OFN_PATHMUSTEXIST and OFN_FILEMUSTEXIST flags.)
OFN_ENABLEHOOK
Enables the hook function specified in the lpfnHook member.
OFN_ENABLETEMPLATE
Causes the operating system to create the dialog box by using the dialog
box
template identified by hInstance and lpTemplateName.
OFN_ENABLETEMPLATEHANDLE
Indicates that hInstance identifies a data block that contains a preloade=
d
dialog box template. The operating system ignores lpTemplateName if this
flag is
specified.
OFN_EXPLORER
Creates an Open or Save As dialog box that uses user-interface features
similar
to the Windows Explorer.
OFN_EXTENSIONDIFFERENT
Specifies that the user typed a filename extension that differs from the
extension specified by lpstrDefExt. The function does not use this flag i=
f
lpstrDefExt is NULL.
OFN_FILEMUSTEXIST
Specifies that the user can type only names of existing files in the File
Name
entry field. If this flag is specified and the user enters an invalid nam=
e,
the
dialog box procedure displays a warning in a message box. If this flag is
specified, the OFN_PATHMUSTEXIST flag is also used.
OFN_HIDEREADONLY
Hides the Read Only check box.
OFN_LONGNAMES
Causes the Open or Save As dialog box to display long filenames. If this
flag is
not specified, the dialog box displays filenames in 8.3 format. This valu=
e
is
ignored if OFN_EXPLORER is set.
OFN_NOCHANGEDIR
Restores the current directory to its original value if the user changed
the
directory while searching for files.
OFN_NODEREFERENCELINKS
Directs the dialog box to return the path and filename of the selected
shortcut
(.LNK) file. If this value is not given, the dialog box returns the path
and
filename of the file referenced by the shortcut.
OFN_NOLONGNAMES
Specifies that long filenames are not displayed in the File Name list box.
This
value is ignored if OFN_EXPLORER is set.
OFN_NONETWORKBUTTON
Hides and disables the Network button.
OFN_NOREADONLYRETURN
Specifies that the returned file does not have the Read Only check box
checked
and is not in a write-protected directory.
OFN_NOTESTFILECREATE
Specifies that the file is not created before the dialog box is closed.
This
flag should be specified if the application saves the file on a
create-nonmodify
network sharepoint. When an application specifies this flag, the library
does
not check for write protection, a full disk, an open drive door, or netwo=
rk
protection. Applications using this flag must perform file operations
carefully,
because a file cannot be reopened once it is closed.
OFN_NOVALIDATE
Specifies that the common dialog boxes allow invalid characters in the
returned
filename. Typically, the calling application uses a hook function that
checks
the filename by using the FILEOKSTRING message. If the text box in the ed=
it
control is empty or contains nothing but spaces, the lists of files and
directories are updated. If the text box in the edit control contains
anything
else, nFileOffset and nFileExtension are set to values generated by parsi=
ng
the
text. No default extension is added to the text, nor is text copied to th=
e
buffer specified by lpstrFileTitle.
If the value specified by nFileOffset is less than zero, the filename is
invalid. Otherwise, the filename is valid, and nFileExtension and
nFileOffset
can be used as if the OFN_NOVALIDATE flag had not been specified.
OFN_OVERWRITEPROMPT
Causes the Save As dialog box to generate a message box if the selected
file
already exists. The user must confirm whether to overwrite the file.
OFN_PATHMUSTEXIST
Specifies that the user can type only valid paths and filenames. If this
flag is
used and the user types an invalid path and filename in the File Name ent=
ry
field, the dialog box function displays a warning in a message box.
OFN_READONLY
Causes the Read Only check box to be checked initially when the dialog bo=
x
is
created. This flag indicates the state of the Read Only check box when th=
e
dialog box is closed.
OFN_SHAREAWARE
Specifies that if a call to the OpenFile function fails because of a
network
sharing violation, the error is ignored and the dialog box returns the
given
filename. If this flag is not specified, the registered message for
SHAREVISTRING is sent to the hook function with a pointer to a
null-terminated
string for the path and filename in the lParam parameter.
OFN_SHOWHELP
Causes the dialog box to show the Help button. The hwndOwner member must
not be
NULL if this option is specified.
nFileOffset

Specifies a zero-based offset from the beginning of the path to the
filename in
the string pointed to by lpstrFile. For example, if lpstrFile points to t=
he
following string, "c:\dir1\dir2\file.ext", this member contains the value
13.

nFileExtension

Specifies a zero-based offset from the beginning of the path to the
filename
extension in the string pointed to by lpstrFile. For example, if lpstrFil=
e
points to the following string, "c:\dir1\dir2\file.ext", this member
contains
the value 18. If the user did not type an extension and lpstrDefExt is
NULL,
this member specifies an offset to the terminating null character. If the
user
typed "." as the last character in the filename, this member specifies 0.

lpstrDefExt

Points to a buffer that contains the default extension. GetOpenFileName a=
nd
GetSaveFileName append this extension to the filename if the user fails t=
o
type
an extension. This string can be any length, but only the first three
characters
are appended. The string should not contain a period (.). If this member =
is
NULL
and the user fails to type an extension, no extension is appended.

lCustData

Specifies application-defined data that the operating system passes to th=
e
hook
function identified by lpfnHook. The system passes the data in the lParam
parameter of the WM_INITDIALOG message.

lpfnHook

Points to a hook function that processes messages intended for the dialog
box.
An application must specify the OFN_ENABLEHOOK flag in the Flags member t=
o
enable the function; otherwise, the operating system ignores this structu=
re
member. The hook function should return FALSE to pass a message to the
standard
dialog box procedure or TRUE to discard the message.
If the hook function processes WM_CTLCOLOR* messages (such as
WM_CTLCOLORDLG),
the function must return a valid brush handle for painting the background
of the
dialog box or the corresponding control.

lpTemplateName

Points to a null-terminated string that names the dialog box template to =
be
substituted for the standard dialog box template. An application can use
the
MAKEINTRESOURCE
 macro for numbered dialog box resources. This member is only used if Fla=
gs
specifies the OFN_ENABLETEMPLATE flag; otherwise, this member is ignored.