Hfrhyu

GetOpenFilename doesn't work in arcobjects VBA, so I have to use pGxDialog.

Standard pGxDialog doesn't let to open any file I want, a few extentions are available only (shp, dxf, xls...).

Maybe, I just don't know how to set a Filter.

I don't need to open extra extension files for reading/writing, I just need to return the PATH of the document to a variable, which will be used later on in the code.

I scripting in VBA, arcgis 10.2.2

You can call directly COM object dll

Private Declare Function GetOpenFileName Lib "comdlg32.dll" Alias "GetOpenFileNameA" (pOpenfilename As OPENFILENAME) As Long

Private Type OPENFILENAME
 lStructSize As Long
 hwndOwner As Long
 hInstance As Long
 lpstrFilter As String
 lpstrCustomFilter As String
 nMaxCustFilter As Long
 nFilterIndex As Long
 lpstrFile As String
 nMaxFile As Long
 lpstrFileTitle As String
 nMaxFileTitle As Long
 lpstrInitialDir As String
 lpstrTitle As String
 flags As Long
 nFileOffset As Integer
 nFileExtension As Integer
 lpstrDefExt As String
 lCustData As Long
 lpfnHook As Long
 lpTemplateName As String
End Type

Function f_OpenFileName(Titre As String) As String
'Function for select file
Dim OpenFile As OPENFILENAME
Dim lReturn As Long
Dim sFilter As String

OpenFile.lStructSize = Len(OpenFile)

'Filter
sFilter = "prj" & Chr(0) & "*.prj" & Chr(0) & Chr(0)
OpenFile.lpstrFilter = sFilter
OpenFile.nFilterIndex = 1
OpenFile.lpstrFile = String(257, 0)
OpenFile.nMaxFile = Len(OpenFile.lpstrFile) - 1
OpenFile.lpstrFileTitle = OpenFile.lpstrFile
OpenFile.nMaxFileTitle = OpenFile.nMaxFile

' default path
OpenFile.lpstrInitialDir = "c:"

'Title
OpenFile.lpstrTitle = Titre
OpenFile.flags = 0
lReturn = GetOpenFileName(OpenFile)

If lReturn = 0 Then
 'message
 f_OpenFileName = 0
Else
 f_OpenFileName = Trim(OpenFile.lpstrFile)
End If
End Function

use function:

Dim txtSelectFile As String
path = f_OpenFileName( "Select a file" )

This is substantially the work of Radar in an answer to a similar question, using the same ArcObjects as Hornbydd does.

I have modified Radar's function for my clients to select a delimited text file then this function returns both the path to the selected file and the file name. This fulfills Alex's request for "...return the PATH of the document to a variable"

I trimmed it down a little so it uses just core ArcObjects libraries.

Public Function BrowseForTextFile(ByVal sTitle As String, ByRef sFolder As String, ByRef sName As String) As Boolean
 'Source: Radar https://gis.stackexchange.com/questions/9000/opening-geodatabase-files-using-browse-dialog-command-vb-net-c-of-arcobjects
 Dim pGxDialog As IGxDialog = New GxDialog
 Dim pGxObjectFilter As IGxObjectFilter = New ESRI.ArcGIS.Catalog.GxFilterTextFiles()

 Dim pFilterCol As IGxObjectFilterCollection
 Dim pEnumGx As IEnumGxObject
 Dim pGxObject As IGxObject

 sFolder = ""
 sName = ""

 pFilterCol = pGxDialog
 pFilterCol.AddFilter(pGxObjectFilter, True)
 pGxDialog.RememberLocation = True
 pGxDialog.AllowMultiSelect = False
 pGxDialog.Title = sTitle


 If pGxDialog.DoModalOpen(0, pEnumGx) Then
 pGxObject = pEnumGx.Next
 sName = pGxObject.Name
 sFolder = pGxObject.Parent.FullName

 Return True
 End If

End Function

You can call this with

Imports ESRI.ArcGIS.Catalog 'for IGxObjectFilter
Imports ESRI.ArcGIS.CatalogUI 'for IGXdialog

Friend m_sFilePathName As String
'...snipped
Dim sCSVPath As String
Dim sCSVName As String
If BrowseForTextFile("Choose a text file to load", sCSVPath, sCSVName) Then
 m_sFilePathName = sCSVPath & "" & sCSVName
 MsgBox("The file you chose was " & m_sFilePathName,MsgBoxStyle.Information, "Result")
Else
 'Nothing chosen, Abort
 Exit Sub
End If

In this case I all I want shown in the dialog is delimited text files, so I use 'GxObjectFilter' of 'GxFilterTextFiles'. You could specify 'GxFilterFiles' if you just want to be able to select "any file"

There are also scores upon scores of coclasses and classes for every object in ArcCatalog if you need to filter the browser dialog to another type. For example you could use 'GxFilterMaps' to target .mxd documents or 'GxFilterFileGeodatabases' to specify FGDBs. You can be even more specific, for example to only choose feature classes within file geodatabases if that's what you need to do.

Below is the code you require:

Public Sub OpenDataset()
 ' Open a dialog for user to select FeatureClasses
 Dim pEnumGXObject As IEnumGxObject
 Set pEnumGXObject = Nothing
 Dim pGxDialog As IGxDialog
 Dim pGXObjectFilter As IGxObjectFilter
 Set pGXObjectFilter = New GxFilterFeatureClasses
 Set pGxDialog = New GxDialog
 With pGxDialog
 .AllowMultiSelect = False
 .Title = "Select a file"
 .ButtonCaption = "Select"
 Set .ObjectFilter = pGXObjectFilter
 .DoModalOpen 0, pEnumGXObject
 End With
 pEnumGXObject.Reset
 Dim pGxobject As IGxObject
 Set pGxobject = pEnumGXObject.Next
 MsgBox pGxobject.FullName
End Sub

I know the question was specifically for VBA, and is a little dated, but since I found this question in a search for a solution to my similar situation, using c#.net, I will post the solution I found.

Firstly, to open any extension not already provided by Catalog, you must define your own custom GX filter class. Below, I create a filter for XML extensions.

public class GxCustomFilter : ESRI.ArcGIS.Catalog.IGxObjectFilter 
 private IGxObjectFilter _basicFilter;

 public GxCustomFilter()
 _basicFilter = new GxFilterBasicTypesClass();
 
 public bool CanChooseObject(ESRI.ArcGIS.Catalog.IGxObject obj, ref ESRI.ArcGIS.Catalog.esriDoubleClickResult result) 
 //Set whether the selected object can be chosen
 bool bCanChoose = false;
 bCanChoose = false;
 if (obj is IGxFile) 
 string sExt = null;
 sExt = GetExtension(obj.Name);
 if (sExt.ToLower() == ".xml") // define your extension here
 bCanChoose = true;
 
 return bCanChoose;
 
 public bool CanDisplayObject(ESRI.ArcGIS.Catalog.IGxObject obj) 
 //Check if objects can be displayed
 try 
 //Check objects can be displayed
 if (_basicFilter.CanDisplayObject(obj))
 return true;
 else if (obj is IGxFile) 
 string sExt = null;
 sExt = GetExtension(obj.Name);
 if (sExt.ToLower() == ".xml") // define your extension here
 return true;
 

 catch (Exception ex) 
 System.Windows.Forms.MessageBox.Show(ex.ToString());
 
 return false;
 
 public bool CanSaveObject(ESRI.ArcGIS.Catalog.IGxObject Location, string newObjectName, ref bool objectAlreadyExists) 
 return false;
 
 public string Description 
 get 
 //Set filet description
 return "eXtensible Markup Language (.xml)";
 
 
 public string Name 
 get 
 //Set filter name
 return "XML filter";
 
 
 private string GetExtension(string sFileName) 
 string tempGetExtension = null;
 //Get extension
 long pExtPos = 0;
 pExtPos = (sFileName.LastIndexOf(".") + 1);
 if (pExtPos > 0)
 tempGetExtension = sFileName.Substring((Int32)pExtPos - 1);
 else
 tempGetExtension = "";
 return tempGetExtension;
 

Then, in your GxDialog, you use the custom class to define a ObjectFilter. You also have to define file filters on the GxDialog.InternalCatalog.

IGxDialog gxDialog = new GxDialog();
IGxCatalog gxCat = gxDialog.InternalCatalog;
IGxFileFilter fileFilter = gxCat.FileFilter;
if (fileFilter.FindFileType("XML") < 0) 
 fileFilter.AddFileType("XML", "eXtensible Markup Language ", "");

IGxObjectFilter objFilter = new GxCustomFilter();
gxDialog.ObjectFilter = objFilter;

If you wish to use the filter with a GxDialog.DoModalSave(), you must modify the custom filter class property CanSaveObject to return true.

I hope this helps someone, as I spent longer than I would have liked figuring it out.