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VB 6 Helper Newsletter
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Rod Stephens
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Aug 19, 2009 10:15 PDT
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I've had two DevX articles posted recently.
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The second part of my DevX WPF 3-D article posted.
WPF Wonders: 3D Drawing with Textures, Transformations, and Realism
(Part 2)</A>
http://www.devx.com/dotnet/Article/42450
To build realism into 3D scenes, you need to draw with the appropriate
materials--and transformations help make the drawing process much
simpler.
This article explains how to use textures to make scenes more realistic.
Textures let you cover 3-D objects with bricks, wood grain, and so
forth.
The article also explains how to use transformations to make building
complex scenes easier.
The final example draws a wooden maze with a stone floor, containing a
spinning globe.
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And a new article on transformations posted. The examples show how to
build some pretty cool robots!
WPF Wonders: Transformations (and Robots!)
http://www.devx.com/dotnet/Article/42497
WPF's transformations make it easy to move, scale, or rotate objects,
and simplify building complex moveable 3D shapes.
This very cool article explains how to use transformations to make it
easeir to produce complex drawings. It explains basic transformations
that produce effects such as rotated, stretched, and skewed text.
I then explains how to use transformations can make building advanced
3-D scenes easier. It explains how to use transformations to model the
parts of a complicated models such as robots and provides two 3-D
examples that build a complex robot arm and a stick figure robot.
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On the HowTo front, I've posted VB 6 and VB .NET versions of a Web page
image scraper that pulls all of the images from a Web page. The two have
slightly different features because some things are easier to do than
others in the two languages. You may want to compare them to see what
you might like to take from one to the other. (For example, the VB 6
version doesn't provide image previews because it doesn't have an
easy-to-use FlowLayoutPanel.)
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Have a great week and thanks for subscribing!
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Rod
RodSte-@vb-helper.com
Books To Keep: http://www.BooksToKeep.com
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*** Now Available ***
Beginning Database Design Solutions
http://www.amazon.com/exec/obidos/ASIN/0470385499/vbhelper/
Visual Basic 2008 Programmer's Reference
http://www.amazon.com/exec/obidos/ASIN/0470182628/vbhelper/
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VB6 Contents:
1. New HowTo: Grab images from a Web page in Visual Basic 6
Both Contents:
2. New Links
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<VB6>
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1. New HowTo: Grab images from a Web page in Visual Basic 6
http://www.vb-helper.com/howto_grab_web_images.html
http://www.vb-helper.com/HowTo/howto_grab_web_images.zip
This description only touches on the most interesting parts of the
program. Download it to see the details.
You can click the links on the WebBrowser to navigate to a Web page, or
enter a URL and click the Go button to navigate there. The following
code shows how the program navigates.
Private Sub cmdGo_Click()
On Error GoTo BadNavigate
wbrWebSite.Navigate txtUrl.Text
Exit Sub
BadNavigate:
MsgBox "Error navigating to web site " & _
txtUrl.Text & vbCrLf & Err.Description, _
vbOKOnly Or vbExclamation, "Navigation Error"
End Sub
After you have navigated to the desired Web page, click the Save button
to execute the following code.
The code gets the WebBrowser's Document property, which returns an
HtmlDocument object representing the Web page, and loops through the
HtmlDocument's Images collection. It calls subroutine DownloadPicture
for each image, passing the routine the image's src property, which
contains the image's URL.
This routine also contains code to let you stop the loop before it
finishes. See the code for details.
Private Sub cmdSaveImages_Click()
Dim doc As HTMLDocument
Dim element As HTMLImg
Dim dir_name As String
If cmdSaveImages.Caption = "Save" Then
Me.MousePointer = vbHourglass
cmdSaveImages.Caption = "Stop"
cmdGo.Enabled = False
DoEvents
' List the images on this page.
dir_name = txtDirectory.Text
If Right$(dir_name, 1) <> "\" Then dir_name = dir_name & "\"
Set doc = wbrWebSite.Document
m_Running = True
For Each element In doc.images
DownloadPicture dir_name, element.src
DoEvents
If Not m_Running Then Exit For
Next element
m_Running = False
cmdSaveImages.Caption = "Save"
cmdGo.Enabled = True
Me.MousePointer = vbDefault
lblFile.Caption = "Done"
Beep
Else
m_Running = False
End If
End Sub
The DownloadPicture subroutine uses an Internet Transfer Control to
download a picture. It calls the control's OpenURL method to download
the image into a byte array. It then opens the appropriate file and
writes the bytes into it.
Private Sub DownloadPicture(ByVal dir_name As String, ByVal url As
String)
Dim file_title As String
Dim file_name As String
Dim pos As Integer
Dim bytes() As Byte
Dim fnum As Integer
url = Trim$(url)
If LCase$(Left$(url, 7)) <> "http://" Then url = "http://" & url
file_title = url
pos = InStrRev(file_title, "/")
If pos > 0 Then file_title = Mid$(file_title, pos + 1)
file_name = dir_name & file_title
Debug.Print "Copying " & url & " to " & file_name
lblFile.Caption = file_title
lblFile.Refresh
' Get the file.
bytes() = inetDownload.OpenURL(url, icByteArray)
' Save the file.
fnum = FreeFile
Open file_name For Binary Access Write As #fnum
Put #fnum, , bytes()
Close #fnum
End Sub
This program still has a few weak spots. For example, it doesn't display
previews of the images so it doesn't let you pick the images you want to
download, it just downloads them all. The .NET version of this program
does a better job of letting you pick images for download.
The program also downloads images when it needs them rather than pulling
them from cache so it isn't as fast as it might be. It also probably
cannot save images that are generated on the fly by the Web server.
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<Both>
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2. New Links
http://www.vb-helper.com/links.html
Math Worksheets World
http://mathworksheetsworld.com/
1,200 printable K-12 math worksheets.
Online Binary-Decimal Converter
http://www.binaryconvert.com/
A quick online application that converts between decimal and binary.
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