Webcam automatic capture after failed login three times

[dyooshi]

Im doing an application which is when user plugged in usb drive, login for will come out asking user to login first but if user failed login for three times, webcam will automatically capture. The problem here, how can I make the webcam to automatically capture after failed login for three times?

Coding for login

Public Class Login
 
    Private Sub LoginButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles LoginButton.Click
        'Check if username or password is empty
        If PasswordTextBox.Text = "" Or UsernameTextBox.Text = "" Then
            MessageBox.Show("Please fill-up all fields!", "Authentication Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
            'Clear all fields
            PasswordTextBox.Text = ""
            UsernameTextBox.Text = ""
 
            'Focus on Username field
            UsernameTextBox.Focus()
 
        Else
            ' Connect to DB
            Dim conn As New System.Data.OleDb.OleDbConnection()
            conn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\\PutLock.mdb;Persist Security Info=True;Jet OLEDB:Database Password=password"
 
            Try
                'Open Database Connection
                conn.Open()
 
                Dim sql As String = "SELECT * FROM PutLockSignUp WHERE Username='" & UsernameTextBox.Text & "' AND Password = '" & PasswordTextBox.Text & "'"
                Dim cmd As OleDbCommand = New OleDbCommand(sql, conn)
 
                Dim sqlRead As OleDbDataReader = cmd.ExecuteReader()
 
                If sqlRead.Read() Then
                    UsernameTextBox.Clear()
                    PasswordTextBox.Clear()
 
                    MainPage.Show()
                    Me.Hide()
 
                Else
                    ' If user enter wrong username or password
                    MessageBox.Show("Sorry, username or password not found!", "Authentication Failure", MessageBoxButtons.OK, MessageBoxIcon.Error)
 
                    'Clear all fields
                    PasswordTextBox.Text = ""
                    UsernameTextBox.Text = ""
 
                    'Focus on Username field
                    UsernameTextBox.Focus()
                End If
 
            Catch ex As Exception
                MessageBox.Show("Failed to connect to Database", "Database Connection Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
            End Try
 
        End If
    End Sub
 
 
    Private Sub ExitButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ExitButton.Click
        End
    End Sub
End Class
 

Here is the coding for webcam

Public Class Form1
    Const WM_CAP As Short = &H400S
    Const WM_CAP_DRIVER_CONNECT As Integer = WM_CAP + 10
    Const WM_CAP_DRIVER_DISCONNECT As Integer = WM_CAP + 11
    Const WM_CAP_EDIT_COPY As Integer = WM_CAP + 30
    Const WM_CAP_SET_PREVIEW As Integer = WM_CAP + 50
    Const WM_CAP_SET_PREVIEWRATE As Integer = WM_CAP + 52
    Const WM_CAP_SET_SCALE As Integer = WM_CAP + 53
    Const WS_CHILD As Integer = &H40000000
    Const WS_VISIBLE As Integer = &H10000000
    Const SWP_NOMOVE As Short = &H2S
    Const SWP_NOSIZE As Short = 1
    Const SWP_NOZORDER As Short = &H4S
    Const HWND_BOTTOM As Short = 1
    Dim iDevice As Integer = 0
    Dim hHwnd As Integer
    Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As IntPtr, ByRef RECT As IntPtr) As IntPtr
    Declare Function SetWindowPos Lib "user32" Alias "SetWindowPos" (ByVal hwnd As Integer, ByVal hWndInsertAfter As Integer, ByVal x As Integer, ByVal y As Integer, ByVal cx As Integer, ByVal cy As Integer, ByVal wFlags As Integer) As Integer
    Declare Function DestroyWindow Lib "user32" (ByVal hndw As Integer) As Boolean
    Declare Function capCreateCaptureWindowA Lib "avicap32.dll" (ByVal lpszWindowName As String, ByVal dwStyle As Integer, ByVal x As Integer, ByVal y As Integer, ByVal nWidth As Integer, ByVal nHeight As Short, ByVal hWndParent As Integer, ByVal nID As Integer) As Integer
    Declare Function capGetDriverDescriptionA Lib "avicap32.dll" (ByVal wDriver As Short, ByVal lpszName As String, ByVal cbName As Integer, ByVal lpszVer As String, ByVal cbVer As Integer) As Boolean
 
    Private Sub LoadDeviceList()
        Dim strName As String = Space(100)
        Dim strVer As String = Space(100)
        Dim bReturn As Boolean
        Dim x As Integer = 0
        Do
            bReturn = capGetDriverDescriptionA(x, strName, 100, strVer, 100)
            If bReturn Then lstDevices.Items.Add(strName.Trim)
            x += 1
        Loop Until bReturn = False
    End Sub
 
    Private Sub OpenPreviewWindow()
        Dim iHeight As Integer = picCapture.Height
        Dim iWidth As Integer = picCapture.Width
        hHwnd = capCreateCaptureWindowA(iDevice, WS_VISIBLE Or WS_CHILD, 0, 0, 640, 480, picCapture.Handle.ToInt32, 0)
        If SendMessage(hHwnd, WM_CAP_DRIVER_CONNECT, iDevice, 0) Then
            SendMessage(hHwnd, WM_CAP_SET_SCALE, True, 0)
            SendMessage(hHwnd, WM_CAP_SET_PREVIEWRATE, 66, 0)
            SendMessage(hHwnd, WM_CAP_SET_PREVIEW, True, 0)
            SetWindowPos(hHwnd, HWND_BOTTOM, 0, 0, picCapture.Width, picCapture.Height, SWP_NOMOVE Or SWP_NOZORDER)
            btnSave.Enabled = True
            btnStop.Enabled = True
            btnStart.Enabled = False
        Else
            DestroyWindow(hHwnd)
            btnSave.Enabled = False
        End If
    End Sub
 
    Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
        Dim data As IDataObject
        Dim bmap As Image
        SendMessage(hHwnd, WM_CAP_EDIT_COPY, 0, 0)
        data = Clipboard.GetDataObject()
        If data.GetDataPresent(GetType(System.Drawing.Bitmap)) Then
            bmap = CType(data.GetData(GetType(System.Drawing.Bitmap)), Image)
            picCapture.Image = bmap
            ClosePreviewWindow()
            btnSave.Enabled = False
            btnStop.Enabled = False
            btnStart.Enabled = True
            If sfdImage.ShowDialog = DialogResult.OK Then
                bmap.Save(sfdImage.FileName, Imaging.ImageFormat.Bmp)
            End If
        End If
    End Sub
 
    Private Sub ClosePreviewWindow()
        SendMessage(hHwnd, WM_CAP_DRIVER_DISCONNECT, iDevice, 0)
        DestroyWindow(hHwnd)
    End Sub
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        LoadDeviceList()
    End Sub
 
    Private Sub btnStart_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnStart.Click
        OpenPreviewWindow()
        btnStart.Enabled = False
        btnStop.Enabled = True
    End Sub
 
    Private Sub btnStop_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnStop.Click
        ClosePreviewWindow()
        btnStart.Enabled = True
        btnStop.Enabled = False
 
    End Sub
End Class

[Oralloy]

dyooshi,

Will you please reformat your code using "CODE" blocks?

Just click the CODE button on the icon bar, and the tags will be automatically inserted for you.

That said, have you run any tests?

What are the test results you've had?

--Oralloy

[dyooshi]

I have tried using timer but I dont know how to use. Both of these coding work fine without error.

[Oralloy]

dyooshi,

Thanks for inserting the code blocks, that really helps with reading and understanding your work.

I'm where I don't have uSloth Office running on this computer, so I'll look around....

Ok, first we have Timer function and Timer event references:

1. Timer Function
2. Form.Timer Event

My Suggestion is that you add an attribute to your Login class which tracks the login failures, and initialise it in the New() method:

Private failCount As Integer
 
Public Sub New()
    failCount = 0
End Sub
 

Then, when there is a login failure, increment it and test for too many tries in LoginButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs):

failCount = 1 + failCount
if (2 < failCount) then
    '' take picture here
    '' eject the USB?
    '' force form closure here
end if
 

Are we thinking in similar ways?

[dyooshi]

this is my updated coding that I did before you reply. it is kinda similar with what you gave but then I dont know how to make the webcam to take picture automatically...

Private Sub LoginButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles LoginButton.Click
        Dim LoginAttempts As Integer = 0
        'Check if username or password is empty
        If PasswordTextBox.Text = "" Or UsernameTextBox.Text = "" Then
            MessageBox.Show("Please fill-up all fields!", "Authentication Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
            'Clear all fields
            PasswordTextBox.Text = ""
            UsernameTextBox.Text = ""
 
            'Focus on Username field
            UsernameTextBox.Focus()
 
        Else
            ' Connect to DB
            Dim conn As New System.Data.OleDb.OleDbConnection()
            conn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\\PutLock.mdb"
 
            Try
                'Open Database Connection
                conn.Open()
 
                Dim sql As String = "SELECT * FROM PutLockSignUp WHERE Username='" & UsernameTextBox.Text & "' AND Password = '" & PasswordTextBox.Text & "'"
                Dim cmd As OleDbCommand = New OleDbCommand(sql, conn)
 
                Dim sqlRead As OleDbDataReader = cmd.ExecuteReader()
 
                If sqlRead.Read() Then
                    MainPage.Show()
                    Me.Hide()
 
                Else
                    LoginAttempts = LoginAttempts + 1
                    If LoginAttempts >= 3 Then
                        'take picture
 
                    Else
                        ' If user enter wrong username or password
                        MessageBox.Show("Sorry, username and password did not match!", "Authentication Failure", MessageBoxButtons.OK, MessageBoxIcon.Error)
 
                        'Clear all fields
                        PasswordTextBox.Text = ""
                        UsernameTextBox.Text = ""
 
                        'Focus on Username field
                        UsernameTextBox.Focus()
                    End If
                End If
 
            Catch ex As Exception
                MessageBox.Show("Failed to connect to Database", "Database Connection Error", MessageBoxButtons.OK, MessageBoxIcon.Error)
            End Try
        End If
    End Sub

[Oralloy]

Well, to take the picture, I would try creating a function similar to that in the message handler in the Form1 class.

Note that you may have to adjust active libraries, so that the correct classes are used here.

Suggestion:

Private Sub TestCameraSave()
    ''--local variables
    Dim data As IDataObject
    Dim bmap As Image
 
    ''--initiate the capture
    SendMessage(hHwnd, WM_CAP_EDIT_COPY, 0, 0)
 
    ''--capture the image from the clip-board
    data = Clipboard.GetDataObject()
 
    ''--process what we got
    If (Not data.GetDataPresent(GetType(System.Drawing.Bitmap))) Then
        '' failed, whinge
        MessageBox "We have a problem here, please insert diagnostics..."
 
    Else
        '' pull bit-map from clip-board
        bmap = CType(data.GetData(GetType(System.Drawing.Bitmap)), Image)
 
        '' save the thing
        bmap.Save("C:/my=image.bmp", Imaging.ImageFormat.Bmp)
 
    End If
End Sub
 

Good Luck!
Oralloy