Parsing file paths

Since I can't seem to remember these functions that work on a full path with filename:

System.IO.Path.GetFileName - extracts the filename part with extensions and loses the leading path
System.IO.Path.GetDirectoryName - extracts the leading path and loses the filename with extension
System.IO.Path.GetExtension - extracts just the extension from the path

Handling autonumber/key fields in a dataset

Problem: If you want to use a dataset and dataadapter exclusively for managing the updates to a table, and the table was designed with an autonumber field as as the primary key, you have to fill in the primary key after the record is inserted.

Solution: The insert statement of the data adapter can't contain the primary key column. You let the underlying data provider fill in the key value. I have taken two solution routes, but they do the same thing. After inserting the row, I updated the row in the mainline code with the new key value in the datagridview and the datatable. My second, more elegant solution, was to attach a row updated event handler to the data adapter. I then fill in the primary key value in the data row. The datagridview picked up the update automatically.


 Private Sub Add_Autonumber(s As Object, e As System.Data.OleDb.OleDbRowUpdatedEventArgs) Handles TViewAdapter.RowUpdated
        If e.StatementType = StatementType.Insert Then
            Dim NewID As Integer
            Dim idCMD As New OleDbCommand("SELECT @@IDENTITY", e.Command.Connection)
            NewID = idCMD.ExecuteScalar
            e.Row("ID") = NewID
        End If
    End Sub

SELECT @@IDENTITY is specific to the oledbconnection for Access databases. SQL has a similar statement. You must do this on the connection that generated the autonumber, hence the command references the rowupdated argument's connection that was passed in

Opening documents in a browser on a form

It was handy to have a preview version of a document on a form.
This is easy for pictures, but not so easy for things like word or PDF

By invoking the webbrowser control, I was able to do that for a PDF file pretty simply
It handles the basic PDF navigation

For Word, its opened up word from the browser pane
To suppress that, I had to change the registry entries for the document class

BrowserFlags 0x8 or 0x9 indicates that a particular app should open in its own window when its associated file is clicked (as opposed to opening within IE. For eg: MS Office docs). 0x10 indicates that when a link is clicked, the existing window should be reused instead of opening a new window. (0x22 in windows explorer - when you open a folder, it opens in an existing window instead of opening a new one). 0x24 or 0x00 indicates that the viewer should be embedded in the browser. 


EditFlags indicates what explorer should do with a particular filetype and/or defines what class it is.
00 01 00 00 turns off the "Confirm open after download" box in IE.
00 00 00 means no special attributes have been defined for that class.
02 00 00 00 is used for the mailto: protocol for mail clients.


The following settings work for the various MS apps


[HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Word.Document.8] "BrowserFlags"=dword:80000024 [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Word.RTF.8] "BrowserFlags"=dword:80000024 [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Word.Document.12] "BrowserFlags"=dword:80000024 [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Word.DocumentMacroEnabled.12] "BrowserFlags"=dword:80000024 [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Excel.Sheet.8] "BrowserFlags"=dword:80000A00 [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Excel.Sheet.12] "BrowserFlags"=dword:80000A00 [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Excel.SheetMacroEnabled.12] "BrowserFlags"=dword:80000A00 [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Excel.SheetBinaryMacroEnabled.12] "BrowserFlags"=dword:80000A00 [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\PowerPoint.Show.8] "BrowserFlags"=dword:800000A0 [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\PowerPoint.Show.12] "BrowserFlags"=dword:800000A0 [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\PowerPoint.ShowMacroEnabled.12] "BrowserFlags"=dword:800000A0 [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\PowerPoint.SlideShow.8] "BrowserFlags"=dword:800000A0 [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\PowerPoint.SlideShow.12] "BrowserFlags"=dword:800000A0 [HKEY_LOCAL_MACHINE\SOFTWARE\Classes\PowerPoint.SlideShowMacroEnabled.12] "BrowserFlags"=dword:800000A0