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There is method to read grayscale image as a 2 dimensional matrix in VB?
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What would you like to do?
Convert an image from color to grayscale? Or something else?
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No.I need to read image pixels which range from 0-255 and then encrypt these values using on e of the substitution techniques.
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Since VB doesn't support pointers, the only method you have is GetPixel. Look into writing the image manipulation code in C#, which does support pointers, and convert the data into a form that VB can use.
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I'm a complete noob so nobody laugh. I am just trying to put a rectangle on the form. When I debug the form loads, paints, the rectangle appears. About 5 seconds later another copy of the rectangle shows up in the wrong place and mostly cut off. If I resize it disappears. It looks like the same size rectangle but positioned at the top left corner of the screen instead of the top left corner of the form. Here is my entire code:
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Me.Refresh()
End Sub
Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
Dim BorderWidth As Integer
Dim TitleHeight As Integer
Dim PenWidth As Integer = 2
BorderWidth = SystemInformation.FrameBorderSize.Width
TitleHeight = SystemInformation.CaptionHeight
Dim bluebrush2 As New Drawing.Pen(Color.Blue, PenWidth)
e.Graphics.DrawRectangle(bluebrush2, 3 + PenWidth, 3 + PenWidth, Me.Size.Width - 8 - (BorderWidth * 2), Me.Size.Height - 8 - (BorderWidth * 2) - TitleHeight)
End Sub
Private Sub Form1_Resize(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Resize
Me.Refresh()
End Sub
End Class
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Hi,
When a form gets a new size (including gets maximized), but also when it gets minimized, the Resize event will fire. When minimizing, the Form's location and size will be fake, which is fine most of the time. However, you have a Refresh() inside the Resize() handler, I have never seen that before, and it doesn't make sense to me. Windows by itself will fire a Paint event if there is a need, typically when you enlarge, uncover, restore or maximize the form, but not when you minimize it. So I suggest to remove the Refresh().
remark: if you put a Panel on the Form, and anchor it to the 4 edges of the form (you can use Visual Designer to add, postion and anchor the Panel), you then can paint in that Panel's Paint handler instead of the Form's Paint handler; the advantage then is you don't have to account for the border width, the caption height, etc. All the coordinates inside the Panel's Paint handler are relative to the top left of the Panel.
Luc Pattyn [Forum Guidelines] [My Articles]
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use the code block button (PRE tags) to preserve formatting when showing multi-line code snippets
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I got rid of the Resize event code and the form load code. As you suggested. I will certainly work toward the panel. However it's still doing the same thing. It draws the rectangle where it belongs and then 5 seconds later draws another one in the wrong place.
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Hi,
I just noticed you got another Refresh(), this one inside the Load handler. Throw it out!
Although once more I don't understand how that could possibly paint outside of your Form, it should not be there at all.
Luc Pattyn [Forum Guidelines] [My Articles]
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use the code block button (PRE tags) to preserve formatting when showing multi-line code snippets
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SeanTWard wrote: BorderWidth = SystemInformation.FrameBorderSize.Width
TitleHeight = SystemInformation.CaptionHeight
Dim bluebrush2 As New Drawing.Pen(Color.Blue, PenWidth)
e.Graphics.DrawRectangle(bluebrush2, 3 + PenWidth, 3 + PenWidth, Me.Size.Width - 8 - (BorderWidth * 2), Me.Size.Height - 8 - (BorderWidth * 2) - TitleHeight)
What's with all the borderWidth, titleHeight, and other junk?? Why could you just get the ClientSize dimensions of the form using Me.ClientSize?? It's everything without the titlebar and border widths.
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Thank you. Added that but the crazy ghost rectangle is still popping up. New code is:
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
End Sub
Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
Dim PenWidth As Integer = 2
Dim ClientHeight As Integer
Dim ClientWidth As Integer
ClientHeight = Me.ClientSize.Height
ClientWidth = Me.ClientSize.Width
Dim bluebrush2 As New Drawing.Pen(Color.Blue, PenWidth)
e.Graphics.DrawRectangle(bluebrush2, 3 + PenWidth, 3 + PenWidth, ClientWidth - 9, ClientHeight - 9)
End Sub
End Class
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Hi,
if you are getting two rectangle outlines, same size, same color, one on the form, one on the screen, there is no way I can think of the code shown could do that. Either your app contains more code that is relevant, or you have some other process (an older version of the same app?) running wild at the same time.
Suggestions:
- Check in Task Manager.
- Close and restart Visual Basic.
- Reboot your system.
Luc Pattyn [Forum Guidelines] [My Articles]
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use the code block button (PRE tags) to preserve formatting when showing multi-line code snippets
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No dice, I closed everything, shut down the computer, booted back up, and tried again. Same thing. Once I resize the window or move it or anything the extra partial rectange goes away and doesn't come back. This is all the code in the app.
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hello every one
There are two forms form1 and form2 form1 has a buttoncontrol init and another form has
tabcontrol init now what i want is that only tabcontrol to be displayed in form1 from form2
for that i had written code in button clisk event like...
Private Sub btn1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn1.Click
Dim doc As New frm2
doc.tabcntrol.Show()
doc.tabcntrol.BringToFront()
doc.show()
doc.Visible = True
End Sub
but what happens is the whole form2 appears as i click on button while i want just tabcontol
from form2 to be visible on buton click event..
so what shall i do..
i am beginner
please help....
thank you
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Hi,
when some Control (say a Button, a TabControl) is on a container (another Control aimed at containing Controls; say a Panel, a Form), you can:
- show the container with the Control
- show the container without the Control
but you can't show the Control without the container.
If the container is not visible, then whatever it contains is also not visible.
You may have to rethink the concepts of your user interface...
Luc Pattyn [Forum Guidelines] [My Articles]
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use the code block button (PRE tags) to preserve formatting when showing multi-line code snippets
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OK, I have this.
Imports System.Net.Mail
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
SendEmail("Skip")
End Sub
Sub SendEmail(ByVal name As String)
Dim mail As New MailMessage()
mail.From = New MailAddress("fromaddy@ee.com")
mail.To.Add("toaddy@ee.com")
mail.Subject = "Skip hire details"
mail.Body = "This is a Test"
Dim smtp As New SmtpClient()
Try
smtp.Send(mail)
Finally
mail.Dispose()
smtp = Nothing
End Try
End Sub
End Class
It is throwing at the smtp.Send(mail) point.
I am trying to keep it simple and so it lacks all sorts of attachments etc, but I cannot see why it is not working.
This part Dim smtp As New SmtpClient() may be part of the trouble, but surely if it is SmtpClient() it defaults to the local computer's settings?
Any pointers?
------------------------------------
"I am always serious about what I do, not necessarily about how I do it."
Tom Baker
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Dalek Dave wrote: It is throwing at the smtp.Send(mail) point.
Standard Question #1: What's the error message??
But, I can probably guess at it. You didn't tell the SmtpClient what the resolvable name or IP address of the SMTP Server is that you're going to use to send the email. Yes, you absolutely must have one somewhere to use. No, you probably can't use your own and have it forward to a known SMTP Server on the net. With the proliferation of spam, most SMTP servers are now requiring a login to send mail and wont forward mail from an untrusted SMTP server.
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Dave Kreskowiak wrote: Standard Question #1: What's the error message??
Failure to connect to remote server
{"No connection could be made because the target machine actively refused it 127.0.0.1:25"}
I have tried changing host to Dim smtp As New SmtpClient("localhost") but this does nothing.
Dave Kreskowiak wrote: You didn't tell the SmtpClient what the resolvable name or IP address of the SMTP Server is that you're going to use to send the email
How do I resolve this? I just want one known machine to email another known machine, it is not for general consumption.
------------------------------------
"I am always serious about what I do, not necessarily about how I do it."
Tom Baker
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I would tend to use my isp's mail server instead of trying to make my own work.
Christian Graus
Driven to the arms of OSX by Vista.
"I am new to programming world. I have been learning c# for about past four weeks. I am quite acquainted with the fundamentals of c#. Now I have to work on a project which converts given flat files to XML using the XML serialization method" - SK64 ( but the forums have stuff like this posted every day )
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Dalek Dave wrote: Failure to connect to remote server
{"No connection could be made because the target machine actively refused it 127.0.0.1:25"}
I have tried changing host to Dim smtp As New SmtpClient("localhost") but this does nothing.
This tells me that your machine isn't running an SMTP server, or there is no hole in the firewall allowing connections on port 25. Either way, you really can't use a server on your machine because no SMTP server is going to trust your machine and forward its mail. You have to use either your corporate mail server or your ISP's.
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Thanks for the pointer, I got hold of them this morning (I was writing app last night in bed!) and have put there smtpclient details in.
Ta Da! It works.
I think it is a PITA that I cannot run localhost.
You were right that Port 25 won't let it in, but speaking to the Tech Guy from our ISP this is because all the arses out there spamming and mass mailing have ruined it for the rest of us! (Which we all knew anyway, but he ranted for about 5 minutes on it anyway!)
Still, nice to get a resolution.
------------------------------------
"I am always serious about what I do, not necessarily about how I do it."
Tom Baker
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I've got a problem that I can't figure out. I have the below section of code running over and over again (probably 10k-15k times). The variables are as follows:
Wd = a single word passed to the function for checking
SkipList = a list of string patterns to use 'like' with (i.e. "##.#[a-z]") - currently 570 strings.
ct = a counter I just put in to make sure it was running through the whole list (it is).
If SkipList.Contains(Wd) Then
Return Nothing
Else
For Each s As String In SkipList
ct += 1
If Wd.ToLower Like s Then
Return Nothing
Exit Function
End If
Next
End If
The code runs, but at seemingly random intervals it runs slow. I put some code in my function to find out where the overall application was running slow and narrowed it down to this block. The strange thing is that it runs through the whole SkipList in 0 milliseconds most of the time, but here and there it comes up with 15.627 milliseconds. The really strange thing is that it's not in the same place every time. I can use the same function, the same list of words (in the same order), and the same SkipList, and the 15.627ms comes up on different words every time I run it, and it's always exactly 15.627ms.
Can anyone tell me what's going on? Or hints as to what else I can do to speed this up?
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Hi,
first of all your observations lack precision. You are relying on the system clock, and that one only advances every 15 milliseconds on your system; if you want to know more about that, read my timers article.
To get more precise measurements, use a better timer (a StopWatch in VB.NET; or a MultiMedia Timer).
Rather than observing say ten times 0 msec, once 15 msec; you will then see say eleven times 1.4 msec
BTW: what is the Exit Function doing in your code?
Luc Pattyn [Forum Guidelines] [My Articles]
- before you ask a question here, search CodeProject, then Google
- the quality and detail of your question reflects on the effectiveness of the help you are likely to get
- use the code block button (PRE tags) to preserve formatting when showing multi-line code snippets
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The code isn't taking exactly 15.627 milliseconds every time it "fails". Unless you're using the high resolution timers, this is the minumum resolution of the timing method you're using.
The problem you have is that you're using 570 different compares against a single word. You need to turn this around and make it so you can do a lookup of the one word on a known list, if at all possible.
Another possibility would be to pre-test the single word to narrow it down to a small number of filters that might apply. If you have a word that starts with a letter, there's no sense in testing a bunch of rules that all start with a number.
But, in the end, it sounds like your code is being stopped by the Garbage Collector while it does it's work. Normally, the GC will stop all threads in your process, walk the object graph looking for things to collect, do it's cleanup work, then resume your threads. Depending on the app, this can take a couple dozen milliseconds, making it look like your code hung for a brief time.
Why is thing happening?? Well, since you're obviously parsing out individual words, you're creating String object after String object, one for each and every word you test. These String objects are dropping out of scope at some point, and the GC has to spend time cleaning them up every once in a while.
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I have a small app for a site manager, (so it has to be simple, right?).
I require a Date, Supplier and Load to be sent to another manager.
I have done this as a Form with a DateTimePicker and two ComboBoxes.
Once the selection is made from these boxes, hit the SEND button and the data is to be emailed to the other manager.
I do not want to go through outlook, just email the data.
I have SD1 as Date, SD2 and SD3 as Text.
Is there some way of just sending SD1, SD2 and SD3 to a single fixed address in as few lines of code as possible and without opening outlook?
(I want the site manager to just choose and click).
Thanks
------------------------------------
"I am always serious about what I do, not necessarily about how I do it."
Tom Baker
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