Hi BubbaMac!

There are many ways to display the Open File dialog in Excel.
Here are your options:


Excel.Application application;
object missing = Type.Missing;

// METHOD 1:
Microsoft.Office.Core.FileDialog fileDialog = application.get_FileDialog(Microsoft.Office.Core.MsoFileDialogType.msoFileDialogOpen);
int cancelled = fileDialog.Show();

// Don't forget to set the Filters and AllowMultiSelect properties

if (cancelled != 0)
{
string fileOpened = fileDialog.Item;

Excel.Workbook workbook = application.Workbooks.Open(fileOpened, ...);
}

// METHOD 2:
// Don't forget to set the FileFilter and MultiSelect parameters
object ret = application.GetOpenFilename(missing, missing, missing, missing, missing);

if (ret is String)
{
string fileOpened = ret.ToString();

Excel.Workbook workbook = application.Workbooks.Open(fileOpened, ...);
}

// METHOD 3:
bool fileOpened = application.Dialogs[Excel.XlBuiltInDialog.xlDialogOpen].Show(
missing, missing, missing, missing, missing, false, missing, missing, missing, missing,
missing, missing, missing, missing, missing, missing, missing, missing, missing, missing,
missing, missing, missing, missing, missing, missing, missing, missing, missing, missing);

if (fileOpened)
{
Excel.Workbook workbook = application.ActiveWorkbook;
}

Hello BubbaMac,

In addition to what Jose said, here is VB.NET code.

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As Microsoft.Office.Tools.Ribbon.RibbonControlEventArgs) Handles Button1.Click
        Dim CustFile As New OpenFileDialog
        Dim wk As Excel.Workbook
        If CustFile.ShowDialog() = DialogResult.OK Then
            wk = Globals.ThisAddIn.Application.Workbooks.Open(CustFile.FileName)
        End If
    End Sub