"Creates an Open dialog box that lets the user specify the drive, directory, and the name of a file or set of files to be opened."
https://docs.microsoft.com/en-us/windows/win32/api/commdlg/nf-commdlg-getopenfilenamea
C# Signature:
[DllImport("comdlg32.dll", SetLastError=true, CharSet = CharSet.Auto)]
static extern bool GetOpenFileName([In, Out] OpenFileName ofn);
VB Signature:
<DllImport("comdlg32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _
Private Shared Function GetOpenFileName(<[In], Out> ByVal ofn As OpenFileName) As Boolean
End Function
F# Signature:
[<DllImport("comdlg32.dll", SetLastError = true)>]
extern bool GetOpenFileName (OpenFileName& ofn)
User-Defined Types:
Alternative Managed API:
Notes:
None.
Tips & Tricks:
Please add some!
C# Sample:
class Program
{
[DllImport("Comdlg32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern bool GetOpenFileName(ref OpenFileName ofn);
static void Main(string[] args)
{
var ofn = new OpenFileName();
ofn.lStructSize = Marshal.SizeOf(ofn);
ofn.lpstrFilter = "All files(*.*)\0\0";
ofn.lpstrFile = new string(new char[256]);
ofn.nMaxFile = ofn.lpstrFile.Length;
ofn.lpstrFileTitle = new string(new char[64]);
ofn.nMaxFileTitle = ofn.lpstrFileTitle.Length;
ofn.lpstrTitle = "Open File Dialog...";
if(GetOpenFileName(ref ofn))
Console.WriteLine(ofn.lpstrFile);
}
}
VB Sample:
' Copyright
' Microsoft Corporation
' All rights reserved
'typedef struct tagOFN {
' DWORD lStructSize;
' HWND hwndOwner;
' HINSTANCE hInstance;
' LPCTSTR lpstrFilter;
' LPTSTR lpstrCustomFilter;
' DWORD nMaxCustFilter;
' DWORD nFilterIndex;
' LPTSTR lpstrFile;
' DWORD nMaxFile;
' LPTSTR lpstrFileTitle;
' DWORD nMaxFileTitle;
' LPCTSTR lpstrInitialDir;
' LPCTSTR lpstrTitle;
' DWORD Flags;
' WORD nFileOffset;
' WORD nFileExtension;
' LPCTSTR lpstrDefExt;
' LPARAM lCustData;
' LPOFNHOOKPROC lpfnHook;
' LPCTSTR lpTemplateName;
'#if (_WIN32_WINNT >= 0x0500)
' void * pvReserved;
' DWORD dwReserved;
' DWORD FlagsEx;
'#endif // (_WIN32_WINNT >= 0x0500)
'} OPENFILENAME, *LPOPENFILENAME;
<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Auto)> _
Public Class OpenFileName
Public structSize As Integer = 0
Public dlgOwner As IntPtr = IntPtr.Zero
Public instance As IntPtr = IntPtr.Zero
Public filter As String = Nothing
Public customFilter As String = Nothing
Public maxCustFilter As Integer = 0
Public filterIndex As Integer = 0
Public file As String = Nothing
Public maxFile As Integer = 0
Public fileTitle As String = Nothing
Public maxFileTitle As Integer = 0
Public initialDir As String = Nothing
Public title As String = Nothing
Public flags As Integer = 0
Public fileOffset As Short = 0
Public fileExtension As Short = 0
Public defExt As String = Nothing
Public custData As IntPtr = IntPtr.Zero
Public hook As IntPtr = IntPtr.Zero
Public templateName As String = Nothing
Public reservedPtr As IntPtr = IntPtr.Zero
Public reservedInt As Integer = 0
Public flagsEx As Integer = 0
End Class 'OpenFileName
Public Class LibWrap
'BOOL GetOpenFileName(LPOPENFILENAME lpofn);
Declare Auto Function GetOpenFileName Lib "Comdlg32.dll" ( _
<[In](), Out()> ByVal ofn As OpenFileName) As Boolean
End Class 'LibWrap
Private Function ShowOpen(Optional ByVal filter As String = ("All files" & ChrW(0) & "*.*" & ChrW(0)), _
Optional ByVal title As String = "Open File Dialog...", _
Optional ByVal defext As String = "*", _
Optional ByVal path As String = "C:\") As String
Try
Dim ofn As New OpenFileName
ofn.structSize = Marshal.SizeOf(ofn)
ofn.filter = filter
ofn.file = New String(New Char(256) {})
ofn.maxFile = ofn.file.Length
ofn.fileTitle = New String(New Char(64) {})
ofn.maxFileTitle = ofn.fileTitle.Length
ofn.initialDir = path
ofn.title = title
ofn.defExt = defext
If LibWrap.GetOpenFileName(ofn) Then
Console.WriteLine("Selected file with full path: {0}", ofn.file)
Console.WriteLine("Selected file name: {0}", ofn.fileTitle)
Console.WriteLine("Offset from file name: {0}", ofn.fileOffset)
Console.WriteLine("Offset from file extension: {0}", ofn.fileExtension)
Return ofn.file
End If
Catch ex As Exception
Debug.Assert(False)
Return System.String.Empty
End Try
End Function
F# Sample
type Flags =
| OFN_ALLOWMULTISELECT = 0x00000200
| OFN_CREATEPROMPT = 0x00002000
| OFN_DONTADDTORECENT = 0x02000000
| OFN_ENABLEHOOK = 0x00000020
| OFN_ENABLEINCLUDENOTIFY = 0x00400000
| OFN_ENABLESIZING = 0x00800000
| OFN_ENABLETEMPLATE = 0x00000040
| OFN_ENABLETEMPLATEHANDLE = 0x00000080
| OFN_EXPLORER = 0x00080000
| OFN_EXTENSIONDIFFERENT = 0x00000400
| OFN_FILEMUSTEXIST = 0x00001000
| OFN_FORCESHOWHIDDEN = 0x10000000
| OFN_HIDEREADONLY = 0x00000004
| OFN_LONGNAMES = 0x00200000
| OFN_NOCHANGEDIR = 0x00000008
| OFN_NODEREFERENCELINKS = 0x00100000
| OFN_NOLONGNAMES = 0x00040000
| OFN_NONETWORKBUTTON = 0x00020000
| OFN_NOREADONLYRETURN = 0x00008000
| OFN_NOTESTFILECREATE = 0x00010000
| OFN_NOVALIDATE = 0x00000100
| OFN_OVERWRITEPROMPT = 0x00000002
| OFN_PATHMUSTEXIST = 0x00000800
| OFN_READONLY = 0x00000001
| OFN_SHAREAWARE = 0x00004000
| OFN_SHOWHELP = 0x00000010
[<Struct>]
[<StructLayout(LayoutKind.Sequential)>]
type OpenFileName =
val mutable lStructSize: int
val mutable hwndOwner: nativeint
val mutable hInstance: nativeint
val mutable lpstrFilter: string
val mutable lpstrCustomFilter: string
val mutable nMaxCustFilter: int
val mutable nFilterIndex: int
val mutable lpstrFile: string
val mutable nMaxFile: int
val mutable lpstrFileTitle: string
val mutable nMaxFileTitle: int
val mutable lpstrInitialDir: string
val mutable lpstrTitle: string
val mutable Flags: Flags
val mutable nFileOffset: int16
val mutable nFileExtension: int16
val mutable lpstrDefExt: string
val mutable lCustData: nativeint
val mutable lpfnHook: nativeint
val mutable lpTemplateName: string
val mutable pvReserved: nativeint
val mutable dwReserved: int
val mutable FlagsEx: int
let mutable ofn = OpenFileName ()
ofn.lStructSize <- Marshal.SizeOf (ofn)
//The first character of this buffer must be NULL if initialization is not necessary.
ofn.lpstrFile <- Char.MinValue.ToString () + new string (' ', 256)
ofn.nMaxFile <- ofn.lpstrFile.Length
ofn.lpstrFileTitle <- new string (' ', 64)
ofn.nMaxFileTitle <- ofn.lpstrFileTitle.Length
ofn.Flags <- Flags.OFN_FILEMUSTEXIST ||| Flags.OFN_PATHMUSTEXIST
if (GetOpenFileName (&ofn)) then
Choice1Of2 ofn.lpstrFile
else
Choice2Of2 (sprintf "GetOpenFileName failed with the error code: %d" (Marshal.GetLastWin32Error ()))
Sample code tiny c OR gcc Cygwin:
tcc (http://bellard.org/tcc/) command line to compile:
tcc -lcomdlg32 openfilename.c
./openfilename.exe is 2,048 bytes !!!
gcc (under cygwin) command line to compile:
gcc -Wall -Wl,--enable-stdcall-fixup -mnop-fun-dllimport -mwindows getopenfilename.c
./a.exe is 61,414 bytes !!!
#include <windows.h>
// tinycc: pull info from CYGWIN header /usr/include/w32api/commdlg.h
#ifdef __TINYC__
#define OFN_READONLY 0x1
#define OFN_OVERWRITEPROMPT 0x2
#define OFN_HIDEREADONLY 0x4
#define OFN_NOCHANGEDIR 0x8
#define OFN_SHOWHELP 0x10
#define OFN_ENABLEHOOK 0x20
#define OFN_ENABLETEMPLATE 0x40
#define OFN_ENABLETEMPLATEHANDLE 0x80
#define OFN_NOVALIDATE 0x100
#define OFN_ALLOWMULTISELECT 0x200
#define OFN_EXTENSIONDIFFERENT 0x400
#define OFN_PATHMUSTEXIST 0x800
#define OFN_FILEMUSTEXIST 0x1000
#define OFN_CREATEPROMPT 0x2000
#define OFN_SHAREAWARE 0x4000
#define OFN_NOREADONLYRETURN 0x8000
#define OFN_NOTESTFILECREATE 0x10000
#define OFN_NONETWORKBUTTON 0x20000
#define OFN_NOLONGNAMES 0x40000
#define OFN_EXPLORER 0x80000
#define OFN_NODEREFERENCELINKS 0x100000
#define OFN_LONGNAMES 0x200000
#define OFN_ENABLEINCLUDENOTIFY 0x400000
#define OFN_ENABLESIZING 0x800000
#define OFN_DONTADDTORECENT 0x2000000
#define OFN_FORCESHOWHIDDEN 0x10000000
#define OFN_EX_NOPLACESBAR 0x1
#define OFN_SHAREFALLTHROUGH 2
#define OFN_SHARENOWARN 1
#define OFN_SHAREWARN 0
typedef UINT_PTR (CALLBACK *LPOFNHOOKPROC) (HWND,UINT,WPARAM,LPARAM);
typedef struct tagOFNA {
DWORD lStructSize;
HWND hwndOwner;
HINSTANCE hInstance;
LPCSTR lpstrFilter;
LPSTR lpstrCustomFilter;
DWORD nMaxCustFilter;
DWORD nFilterIndex;
LPSTR lpstrFile;
DWORD nMaxFile;
LPSTR lpstrFileTitle;
DWORD nMaxFileTitle;
LPCSTR lpstrInitialDir;
LPCSTR lpstrTitle;
DWORD Flags;
WORD nFileOffset;
WORD nFileExtension;
LPCSTR lpstrDefExt;
LPARAM lCustData;
LPOFNHOOKPROC lpfnHook;
LPCSTR lpTemplateName;
void *pvReserved;
DWORD dwReserved;
DWORD FlagsEx;
} OPENFILENAMEA,*LPOPENFILENAMEA;
#define OPENFILENAME OPENFILENAMEA
#define LPOPENFILENAME LPOPENFILENAMEA
#define GetOpenFileName GetOpenFileNameA
#endif
#ifdef __CYGWIN__
#include <commdlg.h>
#endif
// below adapted from: https://www.daniweb.com/software-development/cpp/code/217307/a-simple-getopenfilename-example
int main(int argc, char **argv) {
char szFile[100];
OPENFILENAME ofn;
memset(&ofn, 0, sizeof (ofn));
ofn.lStructSize = sizeof (ofn);
ofn.hwndOwner = NULL;
ofn.lpstrFile = szFile;
ofn.lpstrFile[0] = '\0';
ofn.nMaxFile = sizeof (szFile);
ofn.lpstrFilter = "All\0*.*\0Text\0*.TXT\0";
ofn.nFilterIndex = 1;
ofn.lpstrFileTitle = NULL;
ofn.nMaxFileTitle = 0;
ofn.lpstrInitialDir = NULL;
ofn.Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST;
int i = GetOpenFileName(&ofn);
return(i);
}
Contributed by John Refling
