I have a PictureBox, which I am using as a "Signature pad". The size is 475,175...If the user signs in a small area, I would like to only save the portion that has a signature mark. I am not sure where to begin. Any help would greatly be appreciated.
Private Sub btnSaveSignature_Click(sender As Object, e As EventArgs) Handles btnSaveSignature.Click
Dim signatureFileName = txtSignatureFileName.Text.Trim()
Dim signaturePath As String = Path.Combine(Application.StartupPath, txtSignatureFileName.Text & ".bmp")
If String.IsNullOrEmpty(signatureFileName) Then Return
If currentCurve < 0 OrElse signatureObject(currentCurve).Count = 0 Then Return
Using imgSignature As Bitmap = New Bitmap(pBoxSignature.Width, pBoxSignature.Height, PixelFormat.Format32bppRgb)
Using g As Graphics = Graphics.FromImage(imgSignature)
''BMPs require a White background. This line provide that.
g.FillRectangle(Brsh, 0, 0, pBoxSignature.Width, pBoxSignature.Height)
Call DrawSignature(g)
End Using
pBoxSignature.SizeMode = PictureBoxSizeMode.AutoSize
pBoxSavedSignature.SizeMode = PictureBoxSizeMode.AutoSize
imgSignature.Save(signaturePath, ImageFormat.Bmp)
pBoxSavedSignature.Image = New Bitmap(imgSignature)
End Using
End Sub
The above code is my Save to BMP routine. I would imagine any solution would need to go in this section.
Related
I have a app which is loading between 32^2 to 32768 8x8 px pictureboxes. All pictureboxes are on screen so I need to load them all and can't just load some.
As it stands, my program won't even run. Is there a better way to load that many pictureboxes?
I would like to share with you my project, but I don't know how to.............
Thanks though!
You'd likely run into a MemoryOverflowException with this design. From the sound of it, you're probably trying to render a map of some sort if that's the case then this answer is for you (otherwise just ignore it).
At a high level you should only create the number of PictureBox controls that can fit on the screen at any given time. You can calculate this with the following function:
Private Function CalculateSizeToFitParent(ByVal parent As Control, ByVal childSize As Size) As Size
Return New Size(parent.Width \ childSize.Width, parent.Height \ childSize.Height)
End Sub
You would implement it as such to create a PictureBox to fill up the visible area of the current Form:
Dim pictureBoxSize As Size = New Size(8, 8)
Dim visibleArea(pictureBoxSize.Width - 1, pictureBoxSize.Height - 1) As PictureBox
Dim numberOfPictureBoxes As Size = CalculateSizeToFitParent(Me, pictureBoxSize)
For x As Integer = 0 To numberOfPictureBoxes.Width - 1
For y As Integer = 0 To numberOfPictureBoxes.Height - 1
visibleArea(x, y) = New PictureBox() With {
.Location = New Point(x * pictureBoxSize.Width, y * pictureBoxSize.Height)
.Size = pictureBoxSize
}
Me.Controls.Add(visibleArea(x, y))
Next
Next
The next part is two-fold:
You need to keep track of where the top-left corner of the current visible are is
You will need to reload the images in the respective visual area of the map.
This assumes that you have a 2D array that stores your images. And please note that you don't recreate the PictureBox controls but rather you just reload the image of the existing control:
Private _currentLocation As Point = New Point(0, 0) ' If you're starting somewhere else change it here
Public Property CurrentLocation As Point
Get
Return _currentLocation
End Get
Set(ByVal value As Point)
If (value <> _currentLocation) Then
_currentLocation = value
Me.OnCurrentLocationChanged()
End If
End Set
End Property
Protected Overridable Sub OnCurrentLocationChanged()
RaiseEvent CurrentLocationChanged(Me, EventArgs.Empty)
End Sub
Public Event CurrentLocationChanged(ByVal sender As Object, ByVal e As EventArgs)
Private Sub MyForm_CurrentLocationChanged(ByVal sender As Object, ByVal e As EventArgs) Handles Me.CurrentLocationChanged
If (visibleArea Is Nothing) Then
Throw New Exception("The visible area has not been generated yet.")
End If
If (_currentLocation Is Nothing) Then
Throw New Exception("The CurrentLocation cannot be null.")
End If
Dim widthUpperBounds As Integer = My2DArrayOfImageLocations.GetUpperBounds(0) - 1
Dim heightUpperBounds As Integer = My2DArrayOfImageLocations.GetUpperBounds(1) - 1
For x As Integer = 0 To visibleArea.GetUpperBounds(0) - 1
For y As Integer = 0 To visibleArea.GetUpperBounds(1) - 1
If (x + _currentLocation.Width > widthUpperBounds OrElse y + _currentLocation.Height) Then
'This "block" is outside the view area (display a blank tile?)
Else
visibleArea(x, y).Load(My2DArrayOfImageLocations(x + _currentLocation.Width, y + _currentLocation.Height))
End If
Next
Next
End Sub
Now whenever you reset the CurrentLocation property (however you'd do that, e.g. arrow keys, asdw, etc.) it will redraw the visible area of the map.
Update
Please note that I "free-typed" this example and you may need to tweak it a bit. After some more thought, you'll probably also need to call the Refresh method of the PictureBox when you load in the image (I didn't test).
I am programming an antivirus and really need to know how to change the position of the text that says "Infected!" and "Clean!"
I have not really tried much, because I took a tutorial on how to make it. I do not know how to program in Visual Basic. Sorry I know I'm a noob. Here is the code:
Private Sub btnBrowse_Click(sender As Object, e As EventArgs) Handles btnBrowse.Click
If OpenFileDialog1.ShowDialog = Windows.Forms.DialogResult.OK Then
Dim path As String = OpenFileDialog1.FileName
txtFilePath.Text = path
Dim sample As String
sample = md5_hash(path)
txtHash.Text = md5_hash(path)
Using f As System.IO.FileStream = System.IO.File.OpenRead("md5.txt")
Using s As System.IO.StreamReader = New System.IO.StreamReader(f)
While Not s.EndOfStream
Dim line As String = s.ReadLine
If (line = sample) Then
lblResult.Text = "Infected!"
lblResult.ForeColor = Color.Red
Else
lblResult.Text = "Clean!"
lblResult.ForeColor = Color.Green
End If
End While
End Using
End Using
End If
End Sub
This is only a piece of the code. Please tell me how to fix this. I really could use some help. Thank You!
When trying to change the LOCATION of a label, use the
lblresult.Location = new Point(xCoord here, yCoord here)
Another way to adjust the position would be with the
lblresult.Top += How much you want it to be pushed down/up from its origin
Same is with the
lblresult.Right
lblresult.Left
lblresult.Bottom
Parameters. I think you should give more clear and detailed information about what you are trying to achieve and how one could help you
first of all i am relative new to Visual Basic.NET and i stuck on an problem here.
I started to code a screen2gif recorder. In main purpose it works. But if i record more than 15 to 20 seconds my ram overloads and exceed the 3,5 Gb limit for x32bit applications. The problem is that the bitmaps i create stack over and over.
Private Function getBitmap(ByVal pCtrl As Control) As Bitmap
Dim myBmp As Bitmap
If myBmp IsNot Nothing Then
myBmp.Dispose()
End If
myBmp = New Bitmap(pCtrl.Width, pCtrl.Height)
Dim g As Graphics = Graphics.FromImage(myBmp)
Dim p As New Point(pCtrl.Parent.Width - pCtrl.Parent.ClientRectangle.Width - 4, pCtrl.Parent.Height - pCtrl.Parent.ClientRectangle.Height - 4)
g.CopyFromScreen(pCtrl.Parent.Location + pCtrl.Location + p, Point.Empty, myBmp.Size)
Dim LocalMousePosition As Point
LocalMousePosition = panelTranspacrency.PointToClient(Cursor.Position)
Cursor.Draw(g, New Rectangle(New Point(LocalMousePosition.X, LocalMousePosition.Y), Cursor.Size))
Return myBmp
myBmp.Dispose()
g.Dispose()
End Function
Private Sub tmrWork_Tick(sender As Object, e As EventArgs) Handles tmrWork.Tick
counter += 1
Dim bm As Bitmap
bm = getBitmap(Me.panelTranspacrency)
bm.Save(My.Settings.outputpath & "\temp\" & counter & ".png", Drawing.Imaging.ImageFormat.Png)
bm.Dispose()
End Sub
So this is my code to create the bitmaps and save them to disk.
I mention that i used the .Dispose command but the ram wont free.
Please take a look and give me a hint. Thanks in advance.
Change
Dim g As Graphics = Graphics.FromImage(myBmp)
to
Using g As Graphics = Graphics.FromImage(myBmp)
and put End Using after your Return myBmp. And you should do the same with
Using bm As Bitmap = getBitmap(Me.panelTranspacrency)
And remove all your explicit .Dispose calls as well.
Docs
https://learn.microsoft.com/en-us/dotnet/visual-basic/language-reference/statements/using-statement
I am working on a little tool that allows the selection of a single file. Where it will calculate the SHA2 hash and shows it in a simple GUI then takes the value and checks if that hash is listed in a blacklist text file. If it is listed then it will flag it as dirty, and if not it will pass it as clean.
But after hitting Google for hours on end and sifting through many online sources I decided let's just ask for advise and help.
That said while my program does work I seem to run into a problem, since no matter what I do ,it only reads the first line of my "blacklist" and refuses to read the whole list or to actually go line by line to see if there is a match.
No matter if I got 100 or 1 SHA2 hash in it.
So example if I were to have 5 files which I add to the so called blacklist. By pre-calculating their SHA2 value. Then no matter what my little tool will only flag one file which is blacklisted as a match.
Yet the moment I use the reset button and I select a different (also blacklisted) file, it passes it as clean while its not. As far as I can tell it is always the first SHA2 hash it seems to flag and ignoring the others. I personally think the program does not even check beyond the first hash.
Now the blacklist file is made up very simple.
*example:
1afde1cbccd2ab36f90973cb985072a01ebdc64d8fdba6a895c855d90f925043
2afde1cbccd2ab36f90973cb985072a01ebdc64d8fdba6a895c855d90f925043
3afde1cbccd2ab36f90973cb985072a01ebdc64d8fdba6a895c855d90f925043
4afde1cbccd2ab36f90973cb985072a01ebdc64d8fdba6a895c855d90f925043
....and so on.
So as you can see these fake example hashes are listed without any details.
Now my program is suppose to calculate the hash from a selected file.
Example:
somefile.exe (or any extension)
Its 5KB in size and its SHA2 value would be:
3afde1cbccd2ab36f90973cb985072a01ebdc64d8fdba6a895c855d90f925043
Well as you can see I took the third hash from the example list right?
Now if I select somefile.exe for scanning then it will pass it as clean. While its blacklisted. So if I move this hash to the first position. Then my little program does correctly flag it.
So long story short I assume that something is horrible wrong with my code, even though it seems to be working.
Anyway this is what I got so far:
Imports System.IO
Imports System.Security
Imports System.Security.Cryptography
Imports MetroFramework.Forms
Public Class Fsmain
Function SHA256_SIG(ByVal file_name As String)
Return SHA256_engine("SHA-256", file_name)
End Function
Function SHA256_engine(ByRef hash_type As String, ByRef file_name As String)
Dim SIG
SIG = SHA256.Create()
Dim hashValue() As Byte
Dim filestream As FileStream = File.OpenRead(file_name)
filestream.Position = 0
hashValue = SIG.ComputeHash(filestream)
Dim hash_hex = PrintByteArray(hashValue)
Stream.Null.Close()
Return hash_hex
End Function
Public Function PrintByteArray(ByRef array() As Byte)
Dim hex_value As String = ""
Dim i As Integer
For i = 0 To array.Length - 1
hex_value += array(i).ToString("x2")
Next i
Return hex_value.ToLower
End Function
Private Sub Browsebutton_Click(sender As Object, e As EventArgs) Handles Browsebutton.Click
If SampleFetch.ShowDialog = DialogResult.OK Then
Dim path As String = SampleFetch.FileName
Selectfile.Text = path
Dim Sample As String
Sample = SHA256_SIG(path)
SignatureREF.Text = SHA256_SIG(path)
Using f As System.IO.FileStream = System.IO.File.OpenRead("blacklist.txt")
Using s As System.IO.StreamReader = New System.IO.StreamReader(f)
While Not s.EndOfStream
Dim line As String = s.ReadLine()
If (line = Sample) Then
Result.Visible = True
SignatureREF.Visible = True
Result.Text = "Dirty"
Resetme.Visible = True
RemoveMAL.Visible = True
Else
Result.Visible = True
SignatureREF.Visible = True
Result.Text = "Clean"
Resetme.Visible = True
RemoveMAL.Visible = False
End If
End While
End Using
End Using
End If
End Sub
Private Sub Fsmain_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Result.Visible = False
SignatureREF.Visible = False
Resetme.Visible = False
RemoveMAL.Visible = False
End Sub
Private Sub Resetme_Click(sender As Object, e As EventArgs) Handles Resetme.Click
Selectfile.Text = Nothing
SignatureREF.Text = Nothing
Result.Visible = False
SignatureREF.Visible = False
Resetme.Visible = False
RemoveMAL.Visible = False
End Sub
Private Sub RemoveMAL_Click(sender As Object, e As EventArgs) Handles RemoveMAL.Click
Dim ask As MsgBoxResult = MsgBox("Would you like to remove the Dirty file?", MsgBoxStyle.YesNo, MessageBoxIcon.None)
If ask = MsgBoxResult.Yes Then
System.IO.File.Delete(Selectfile.Text$)
Else
MsgBox("You sure you want to keep this file?")
Dim filepath As String = IO.Path.Combine("c:\Dirty\", "Dirty.txt")
Using sw As New StreamWriter(filepath)
sw.WriteLine(" " & DateTime.Now)
sw.WriteLine(" " & Selectfile.Text)
sw.WriteLine(" " & SignatureREF.Text)
sw.WriteLine(" " & Result.Text)
sw.WriteLine("-------------------")
sw.Close()
End Using
End If
End Sub
End Class
So if any of you guys can have a look at it and point out errors, or even can come up with a fix that would be great.
The simplest thing you can do to make your procedure working, is testing whether a defined condition is verified. Terminate the test if that condition is met.
Using a boolean variable, report the result of the test and take action accordingly.
The Using statement takes care of disposing the StreamReader.
You could modify you procedure this way:
Private Sub Browsebutton_Click(sender As Object, e As EventArgs) Handles Browsebutton.Click
If SampleFetch.ShowDialog <> DialogResult.OK Then Exit Sub
Dim sample As String = SHA256_SIG(SampleFetch.FileName)
SignatureREF.Text = sample
Dim isDirty As Boolean = False
Using reader As StreamReader = New StreamReader("blacklist.txt", True)
Dim line As String = String.Empty
While reader.Peek() > 0
line = reader.ReadLine()
If line = sample Then
isDirty = True
Exit While
End If
End While
End Using
If isDirty Then
'(...)
RemoveMAL.Visible = True
Result.Text = "Dirty"
Else
'(...)
RemoveMAL.Visible = False
Result.Text = "Clean"
End If
End Sub
If you have a String and you want to test whether it matches a line of a text file then you can use this simple one-liner:
If IO.File.ReadLines(filePath).Contains(myString) Then
I'm working on Visual Inspection System. One of my key function is to compare an image captured with an image from a data base. The comparison would reveal missing parts or damaged part. I have tried using pixel comparison, but this method is not reliable as it needs exactly similar image captured every time. Is there a way to improve this function to be more versatile. In a way it has to detect the difference in image even if the image captured is slightly offset or rotated. Please guide me using VB.Net. Below is my current code.
Private Sub btnGo_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles btnGo.Click
Me.Cursor = Cursors.WaitCursor
Application.DoEvents()
' Load the images.
Dim bm1 As Bitmap = Image.FromFile("C:\Users\pnasguna\Desktop\A56.jpg")
Dim bm2 As Bitmap = Image.FromFile("C:\Users\pnasguna\Desktop\A54.jpg")
' Make a difference image.
Dim wid As Integer = Math.Min(bm1.Width, bm2.Width)
Dim hgt As Integer = Math.Min(bm1.Height, bm2.Height)
Dim bm3 As New Bitmap(wid, hgt)
' Create the difference image.
Dim are_identical As Boolean = True
Dim eq_color As Color = Color.White
Dim ne_color As Color = Color.Red
For x As Integer = 0 To wid - 1
For y As Integer = 0 To hgt - 1
If bm1.GetPixel(x, y).Equals(bm2.GetPixel(x,y)) Then
bm3.SetPixel(x, y, eq_color)
Else
bm3.SetPixel(x, y, ne_color)
are_identical = False
End If
Next y
Next x
' Display the result.
PictureBox1.Image = bm3
Me.Cursor = Cursors.Default
If (bm1.Width <> bm2.Width) OrElse (bm1.Height <> bm2.Height) Then are_identical =False
If are_identical Then
MessageBox.Show("The images are identical")
Else
MessageBox.Show("The images are different")
End If
bm1.Dispose()
bm2.Dispose()
End Sub
You could take the XnaFan ImageComparison library to inspectionate the sourcecode as an example for your needs
It reveals the difference between pixels and can compare images with a Similarity coefficient, I've write a basic example of both:
Imports XnaFan.ImageComparison
' ===================================================
' Get percentage difference value between two images:
' ===================================================
Dim img1 As Image = Image.FromFile("C:\Image1.jpg")
Dim img2 As Image = Image.FromFile("C:\Image2.jpg")
Dim PercentageDifference As Single =
ImageTool.PercentageDifference(img1:=img1, img2:=img2, threshold:=3)
MessageBox.Show(String.Format("Percentage Difference: {0}%",
CSng(PercentageDifference * 100I).ToString("n1")))
' ========================================
' Get difference image between two images:
' ========================================
Dim img1 As Image = Image.FromFile("C:\Image1.jpg")
Dim img2 As Image = Image.FromFile("C:\Image2.jpg")
Dim DifferenceBitmap As Bitmap =
ImageTool.GetDifferenceImage(img1:=img1,
img2:=img2,
adjustColorSchemeToMaxDifferenceFound:=True,
absoluteText:=False)
PictureBox1.Image = DifferenceBitmap
If you want something more complex you could use AForge (Imaging) library to do the similarity comparison