Visual Basic

Problems resizing image in VB.NET

28-Sep-07 11:00

mostafaelfeky wrote:
while i enabled all the protocols (via, tcp/ip, pipes,...) in the sql server

Well, you have to enable TCP/IP and remote connections, but you also have to enable Integrated Security.

Other than that, we'd have to see the connection string you're using.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Kombu28-Sep-07 10:03

Kombu

28-Sep-07 10:03

I'm reading a series of images from a MS SQL table and saving them to directory. As part of the process, I'm resizing the image and changing its resolution from 96 to 72 ppi. The resizing works without a hitch, but I cannot figure out how to reduce the resolution. All of the output files continue to be 96 ppi. Any help would be greatly appreciated.

Here's the code

<snip...>
Dim bytImage() As Byte
bytImage = .ItemArray(4)
bytImage = ChangeImageResolution(bytImage, 72)
bytImage = ResizeImage(bytImage, 150)
Dim fs As New FileStream(strFileName, FileMode.OpenOrCreate, FileAccess.Write)
fs.Write(bytImage, 0, UBound(bytImage))
fs.Close()
fs = Nothing
<snip...>
Private Function ChangeImageResolution(ByVal bytInput As Byte(), ByVal intOutputResolution As Int16) As Byte()
Dim strmInput As New System.IO.MemoryStream(bytInput)
Dim strmOutput As New System.IO.MemoryStream
Dim imgInput As System.Drawing.Image
Dim imgOutput As System.Drawing.Image
Dim bmapTemp As Bitmap

' Create a temporary bitmap and set to output resolution
imgInput = System.Drawing.Image.FromStream(strmInput)
bmapTemp = imgInput
bmapTemp.SetResolution(intOutputResolution, intOutputResolution)
imgOutput = New Bitmap(bmapTemp)
imgOutput.Save(strmOutput, System.Drawing.Imaging.ImageFormat.Jpeg)

' Return the output image in a byte array
ChangeImageResolution = strmOutput.ToArray
End Function
Private Function ResizeImage(ByVal bytInput As Byte(), ByVal intFinalMaxDim As Int16) As Byte()
Dim strmInput As New System.IO.MemoryStream(bytInput)
Dim strmOutput As New System.IO.MemoryStream
Dim imgInput As System.Drawing.Image
Dim imgOutput As System.Drawing.Image
Dim intMaxDim As Int16 = 0
Dim intResizePercentage As Double = 0
Dim sizResize As New Size

' Determine the resizing percentage based on current image dimensions
imgInput = System.Drawing.Image.FromStream(strmInput)
If imgInput.Height >= imgInput.Width Then
intMaxDim = imgInput.Height
Else
intMaxDim = imgInput.Width
End If
intResizePercentage = (intFinalMaxDim / intMaxDim)
With sizResize
.Width = CInt(imgInput.Width * intResizePercentage)
.Height = CInt(imgInput.Height * intResizePercentage)
End With

' Create a new resized version of the image
imgOutput = New Bitmap(imgInput, sizResize.Width, sizResize.Height)
imgOutput.Save(strmOutput, System.Drawing.Imaging.ImageFormat.Jpeg)

' Return the output image in a byte array
ResizeImage = strmOutput.ToArray
End Function

Re: Problems resizing image in VB.NET

Dave Kreskowiak28-Sep-07 10:59

Re: Problems resizing image in VB.NET

28-Sep-07 10:59

The dpi is just metadata in the image. It has no effect on the display, printing, or quality of the image. It's kind of like a footnote.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Kombu28-Sep-07 12:35

Kombu

28-Sep-07 12:35

Dave,

Thanks for your response. Sorry about the ppi/dpi confusion – my graphics app uses "ppi" and Windows uses "dpi".

To further clarify my problem...these are staff ID pictures from our security card app. Once I've extracted the ID photo from the security app to disk, I need to reference the disk file in our HR app. The images are not printed from the HR app, but if they are not at a 72 dpi resolution, the HR app freezes. Somehow I've got to figure out how to change the resolution.

Simulating a mouseclick

The real $M@28-Sep-07 8:31

The real $M@

28-Sep-07 8:31

There's a picture in a program (not mine). How can I simulate a click on the picture? (I know the coordinates)
Thanks,
SMA

Re: Simulating a mouseclick

Dave Kreskowiak28-Sep-07 9:36

28-Sep-07 9:36

There is no "SendMouse" or "SendClick" so you have to use the Win32 API functions FindWindowEx to get the window that the image is in, get it's window handle, then use the API function SendMessage to send carefully crafted WM_LBUTTONDOWN and WM_LBUTTONUP messages to that window.

Warning: This is NOT something for beginners!! You have to have specific knowledge of how Windows works and how your application works. If you don't have sufficient research skills, you'll find this a very frustrating experience.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Wizard Creation

zoljin28-Sep-07 5:49

zoljin

28-Sep-07 5:49

Hi,

I'm looking for a guide to create a wizard on VB 2003.
I did find many articles and guides how to create wizards in C++\C#\VB2005, but not a single one besides from microsoft's guide (which I didnt understand much of):
http://msdn2.microsoft.com/en-us/library/7k3w6w59(vs.71).aspx[^]

Must I mention that I'm new to VB, and if anyone could explain to me how to, and what to, that'd be greate. PLEASE PLEASE PLEASE.

Re: Wizard Creation

Dave Kreskowiak28-Sep-07 6:20

Visual Studio error opening form file, help tracing location

28-Sep-07 6:20

The link you posted doesn't create a Wizard, but is a Wizard that helps you create an Add-In for Visual Studio. Confused | :confused:

Have you tried looking at the code in this article[^]?

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

svanwass28-Sep-07 5:35

svanwass

28-Sep-07 5:35

I am working with Visual Studio 2005 w/ Service Pack 1 for Vista

I experienced a crash in Vista last night while "playing" my app. As it was the end of the day, I did not log back in and went home.

I came back in today, opened my solution and now am greeted by a friendly message from Visual Studio when I attempt to open the form [design] telling me that "The file cannot be opened with the selected editor. Please choose another editor. "

If I build the project, I get an error saying "String cannot have zero length" The file specified is "LC" (which is not the name of anything I have in my solution.). No line number is listed, nor column.

I am able to open the code for the form, the form designer, and a separate form in my solution.

I've Googled the error and so far found nothing that is of any help.

I am hoping that the good people of Code Project have seen this before and might know of how I can track down what is causing the problem or a fix.

Thanks in advanced!

-Steve

Re: Visual Studio error opening form file, help tracing location

Dave Kreskowiak28-Sep-07 6:17

Re: Visual Studio error opening form file, help tracing location

28-Sep-07 6:17

I don't use Vista, and haven't seen that problem under XP yet either.

The first thing I'd try would be to close the Solution, go into the Projects folder and delete the .SUO file (which is normally hiddden). Then try reopening the project.

After that, I would suspect that one of the files for that form has been corrupted somehow. I'd probably try salvaging the code for the form by opening its .vb file in Notepad and copying it to another file, then delete the form from the project, making sure the .vb, .resx, and .designer.vb files are removed, then recreate then form with all the controls using the same names you used before. You can copy and paste the code you salvaged back into the form's code.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

svanwass28-Sep-07 7:18

svanwass

28-Sep-07 7:18

Thanks for the suggestion Dave.

Deleting the SUO file did not fix it, but like a cautious VS user, I had a backup from a couple days ago I restored and updated with the notepad opened VB files. Still wish I could track down what went wrong for the time I don't have a backup or for other users.

Showing webpages

The real $M@28-Sep-07 5:14

The real $M@

28-Sep-07 5:14

How can I show the contents of a webpage in my program?
(F. e. if I'm making a web-browser)

The real $M@

svanwass28-Sep-07 5:38

svanwass

28-Sep-07 5:38

I found this which might help...

The real $M@28-Sep-07 20:38

The real $M@

28-Sep-07 20:38

Thanks very much:->

DigiOz Multimedia28-Sep-07 8:47

DigiOz Multimedia

28-Sep-07 8:47

The real $M@ wrote:
How can I show the contents of a webpage in my program?
(F. e. if I'm making a web-browser)

Try the following article on Code Project:

http://www.codeproject.com/vb/net/IE7_Clone_VS2005_Browser.asp[^]

Pete Soheil
DigiOz Multimedia
http://www.digioz.com

Dave Kreskowiak28-Sep-07 9:21

28-Sep-07 9:21

This is the same link the other person gave. You might want to read the other posts before you reply.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Accessing controls on startup Form

DigiOz Multimedia28-Sep-07 19:20

DigiOz Multimedia

28-Sep-07 19:20

Dave Kreskowiak wrote:
This is the same link the other person gave. You might want to read the other posts before you reply.

You are absolutely right. My appologies for this.

Pete Soheil
DigiOz Multimedia
http://www.digioz.com

AliAmjad28-Sep-07 4:21

28-Sep-07 4:21

Hi to all,
My question is a simple one how can i access controls of Startup Form from another class. Means i want to access that instance of the form which is available in the memory, don't want to create another instance. Thanx !!!

-- AliAmjad --

Dave Kreskowiak28-Sep-07 6:10

28-Sep-07 6:10

AliAmjad wrote:
how can i access controls of Startup Form from another class.

In proper OOP programming, you don't. The only class responsible for those controls would be the form class. Your other classes do not need to know about those controls, nor should they even care to update them themselves. This would tie your other class to that form so hard you would be able to use the class in any other project.

Your class should be exposing events and properties that your Form class can get to and subscribe to so the form updates it's own controls, not the other way around.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

AliAmjad29-Sep-07 4:22

29-Sep-07 4:22

Thanks for the reply. But i think it's not applicable in the scenario which i am facing. What if i am using the class which is responsible for raising events in many other classes then what should i do.

I've actually created a class named InformationReceived.vb

Declared its variable in a module. Then handled this class in that module here is the code:

Module GlobleMDL

Public WithEvents infoRec As New InformationReceived

Private Sub infoRec_Information_Received(ByVal info As String) Handles infoRec.Information_Received

MsgBox(info)

End Sub

End Module

Now instead of using msgbox whatever information i am receiving for other classes i want to display it on the statup form's Textbox.

If i declare and handles this class in the startup form's class then how can other classes access the instance of this class(informationReceived.vb)

Dave Kreskowiak29-Sep-07 5:16

29-Sep-07 5:16

AliAmjad wrote:
But i think it's not applicable in the scenario which i am facing.

No such thing...

AliAmjad wrote:
If i declare and handles this class in the startup form's class then how can other classes access the instance of this class(informationReceived.vb)

They can't. You're going about this all wrong, and the method you've come up with won't even work. Scrap this class/Module/whatever, you don't need it.

In your property getters/setters, you put Debug.Trace statements. Trace messages are caught by any of the TraceListener classes. You create this TraceListener in your main form and it'll hear all of these message no matter where they came from. Then you can Append each message in a TextBox.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

AliAmjad29-Sep-07 7:16

29-Sep-07 7:16

Dave man i am really thankful to you. Just the final question because i am learning allot here. How can i append the messages to the Textbox and where to handle the class or when am i sure that i have received the message.

I've created the instance of DefaultTraceListner in the main form. And using Trace.Writeline for receiving information from other classes.

Thanks Again... Smile | :)

Dave Kreskowiak29-Sep-07 8:17

29-Sep-07 8:17

AliAmjad wrote:
How can i append the messages to the Textbox

It's easy. I occasionally use this quick'n'dirty class to do the same thing while I'm writing an app:

Public Class TraceLogSupport
    Inherits TraceListener
 
    Private _targetTextBox As TextBox = Nothing
 
    Public Sub New(ByVal TextBoxControl As TextBox)
        Mybase.New()
        If TextBoxControl IsNot Nothing Then
            _targetTextBox = TextBoxControl
        Else
            MyBase.Dispose()
            Throw New ArgumentNullException("You must specify a TextBox control to use to show log information.")
        End If
    End Sub
 
    Public Overrides Sub Write(ByVal message As String)
        _targetTextBox.AppendText(message)
    End Sub
 
    Public Overrides Sub WriteLine(ByVal message As String)
        Me.Write(message & Environment.NewLine)
    End Sub
End Class

To use it, all you do is creat an instance of it and pass it a TextBox you want it to use to log information to. I usually just use a small form with a TextBox on it and do something like this in it's Load event:

    Private _tractListener As TraceLogSupport
 
...
 
    Private Sub LogForm_Load(blah, blah) Handles MyBase.Load
        _traceListener = New TraceLogSupport(LogTextBox)
        Trace.AutoFlush = True
        Trace.Listeners.Add(_traceListener)
    End Sub

That's it, except for peppering the code with Trace.Write and Trace.WriteLine statements...

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

AliAmjad29-Sep-07 11:39