The Visual Basic Team : Daniel Walzenbach

Free SQL Server 2008 Express How-To-Guide Series

VBTeam — Thu, 01 Oct 2009 01:27:00 GMT

Thanks to the SQL Server Team we just released a free SQL Server 2008 Express How-To-Guide Series on msdev.com. During the next weeks we’ll also integrating parts of the series into the Visual Basic Developer Center, C# Developer Center, the Beginner Developer Learning Center, etc.

One video of the series: How do I query data in a database?

Given the fact that we don’t have unlimited resources (yeah, I know… that was the biggest surprise for me as well when I started working at Microsoft. “Where are all the bags with money standing around in each corner? What? There are none? D’oh!”) we tried to cover a pretty comprehensive area starting with basics like “How do I create a database?” over “How do I query data in a database?” to more advanced features like “How do I import data from another source (Excel, Access, XML, MySQL, ...) into a SQL Server Database?”.

Please let me know how you like the selection we made and if there are other topics you’d like to see*.

Enjoy!

Daniel

P.S.: We’ll rearrange the videos soon to have a nice walkthrough including “Topics you should know before watching this video” and “Next videos you might want to watch”.

* I don’t want to raise wrong expectations in that I’m promising other videos to show up on request but depending on the topic/amount of people requesting content we might extend the series.

When using LINQ to XML why don’t I get results if I don’t import a XML namespace (Daniel Walzenbach)?

VBTeam — Thu, 30 Apr 2009 03:20:00 GMT

Hi,

I posted a bit of code the other day which I used to get a list of all Code Snippets we ship in Visual Studio. In a nutshell, I used XElement.Load to create a new XML document from a filename from which I then read elements from (There are way to many ‘”from” in this sentence ;-) ). Unfortunately, I forgot to import the XML Namespace in the code I posted which caused my code not to return any results (but instead provided me with a brilliant opportunity to write another post. hehe :-) ).

Let’s have a look at the code which is causing trouble and a Code Snippets to understand what’s going on (you can find the complete code including the Snippet class in the aforementioned post):

Dim query = _

From file In My.Computer.FileSystem.GetFiles( _

"C:\Program Files\Microsoft Visual Studio 10.0", _

FileIO.SearchOption.SearchAllSubDirectories) _

Where file.EndsWith(".snippet") _

Order By file

Dim snippets As New List(Of Snippet)

Dim snippetDocument As XElement

Dim snippet As Snippet

For Each item In query

snippetDocument = XElement.Load(item)

If snippetDocument...<Title>.Value IsNot Nothing Then

snippet = New Snippet With {.Title = snippetDocument...<Title>.Value.ToString _

, .Description = snippetDocument...<Description>.Value.ToString _

, .Path = item _

, .Size = New System.IO.FileInfo(item).Length}

snippets.Add(snippet)

End If

Code Snippet

<?xml version="1.0" encoding="utf-8"?>

<Title>Activate a Running Application by Name</Title>

<Author>Microsoft Corporation</Author>

<Description>Activates a running application using the name of the application.</Description>

<Shortcut>appActNa</Shortcut>

</Header>

<Namespace>Microsoft.VisualBasic</Namespace>

</Import>

</Imports>

<ID>applicationName</ID>

<Type>String</Type>

<ToolTip>Replace with the name of the application. This is often the title of the application window.</ToolTip>

<Default>"Untitled - Notepad"</Default>

</Literal>

</Declarations>

</Snippet>

</CodeSnippet>

</CodeSnippets>

As you can see there is a <Title> element in the the Code Snippet to which we are referring to in the code above… or are we?

Let’s dig a bit deeper, open the compiled program in .NET Reflector and disassemble it (if you don’t have .NET Reflector you have to stop reading NOW and get it!! Seriously, this tool is a life-safer and I’ve learned soooo much using it!).

If you focus on the parts I highlighted in red in the above picture you can see that <Title> consists out of the XML name and the XML namespace (check out XName..::.Get Method (String, String)). Since I didn’t import the namespace in my program an empty namespace got used resulting in the qualified name Title which doesn’t fit the namespace of the Code Snippet {http://schemas.microsoft.com/VisualStudio/2005/CodeSnippet}Title, hence my program didn’t return any results.

To solve this problem I added the following line of code to my program

Imports <xmlns="http://schemas.microsoft.com/VisualStudio/2005/CodeSnippet">

and – finally – all is good :-)

Hopefully this solved the mystery of the missing results ;-)

Best!

Daniel

How to get a list of all files of a directory (subdirectories included) (Daniel Walzenbach)?

VBTeam — Thu, 23 Apr 2009 21:53:00 GMT

I needed to create a list of all Code Snippets we ship in Visual Studio the other day containing their title, description and path on disc and size. As you might know, Code Snippets are stored in multiple directories below "%ProgramFiles%\Microsoft Visual Studio 10.0" so I had to traverse all the subdirectories of the aforementioned path to find all snippets.

Fortunately – linq to the rescue – this came down to a few lines of code :-)

Dim query = From file In My.Computer.FileSystem.GetFiles("C:\Program Files\Microsoft Visual Studio 10.0", FileIO.SearchOption.SearchAllSubDirectories) _

Where file.EndsWith(".snippet") _

Order By file

This statement gives you a List of Strings (or, to be a bit more precise, a System.Linq.IOrderedEnumerable(Of String)) which you can walk over to do all kinds of crazy things.

Here is what I did to solve the problem I described above:

Imports <xmlns="http://schemas.microsoft.com/VisualStudio/2005/CodeSnippet">

Public Class Form1

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

Dim query = From file In My.Computer.FileSystem.GetFiles(txtPath.Text, FileIO.SearchOption.SearchAllSubDirectories) _

Where file.EndsWith(".snippet") _

Order By file

Dim snippets As New List(Of Snippet)

Dim snippetDocument As XElement

Dim snippet As Snippet

For Each item In query

snippetDocument = XElement.Load(item)

If snippetDocument...<Title>.Value IsNot Nothing Then

snippet = New Snippet With {.Title = snippetDocument...<Title>.Value.ToString _

, .Description = snippetDocument...<Description>.Value.ToString _

, .Path = item _

, .Size = New System.IO.FileInfo(item).Length}

snippets.Add(snippet)

End If

DataGridViewSnippets.AutoGenerateColumns = True

DataGridViewSnippets.DataSource = snippets

End Sub

End Class

Public Class Snippet

Private _Title As String

Private _Description As String

Private _Path As String

Private _Size As Long

Public Property Title() As String

Get

Return _Title

End Get

Set(ByVal value As String)

_Title = value

End Set

End Property

Public Property Description() As String

Get

Return _Description

End Get

Set(ByVal value As String)

_Description = value

End Set

End Property

Public Property Path() As String

Get

Return _Path

End Get

Set(ByVal value As String)

_Path = value

End Set

End Property

Public Property Size() As Long

Get

Return _Size

End Get

Set(ByVal value As Long)

_Size = value

End Set

End Property

End Class

Btw, if you bind the result to a DataGridView you can copy&paste from there into excel. Needo :-)

Cheers!

Daniel

Edited April 29, 2009: Included the "Imports" statement and did some cleanup work.

Two free e-books available till April 22th to celebrate MS Press’s 25th b-day (Daniel Walzenbach)

VBTeam — Fri, 17 Apr 2009 00:30:00 GMT

2009 is the 25th anniversary of Microsoft Press! To celebrate their b-bay they’re giving away two free e-books, namely

Windows Small Business Server 2008 Administrator's Companion by Charlie Russel and Sharon Crawford (27 chapters, 3 appendices, 712 pages)
Microsoft Visual Basic 2008 Express Edition: Build a Program Now! by Patrice Pelland (9 chapters, Glossary, 254 pages)

Before opening one of the links make sure that you disable your Pop-Up blocker as the window containing the book will be opened in a new window. Additionally, when the new window gets opened give it some time to show the content as the VB book is roughly 8MB and the Windows Small Business Server book is around 24MB.

To download the book click "Page >> Save As..." and rename the download in the Save window.

Get them as soon as the offer lasts (April 22nd) :-)

Daniel

Edited April 22, 2009: Included the last section on "How to download the ebooks".