Progress bar problem

[stoui333]

Hi all i`m trying to use a progress bar while i click a button to start my web cam.

It needs about 2-3 seconds to display the web cam capture image in my picture box.

When i use the following code the progress bar starts only when the capture image is displayed in my picture box, it waits those seconds to start.

What can i do about that problem?

 Private Sub TimerProgreesBar_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TimerProgreesBar.Tick

        If ProgressBar1.Value = ProgressBar1.Maximum Then
            ProgressBar1.Visible = False
            TimerProgreesBar.Enabled = False
        Else
            ProgressBar1.Value = ProgressBar1.Value + 10
        End If
    End Sub

[Siddharth Rout]

Could you show the complete code please...

[7777]

Your thread is blocked with the call to capCreateCaptureWindowA (or however you're doing it) I think you're going to need another thread to display the update information.

[stoui333]

Ok heres how i set up camera

 Public Sub startCam(ByVal parentH As Integer)
       
       
        window_handle1 = capCreateCaptureWindowA(iDevice, WS_VISIBLE Or WS_CHILD, 0, 0, OutputWidth, CShort(OutputHeight), parentH, 0)


        If setCam() = False Then
            MessageBox.Show("Error setting Up Camera")
        End If
       
    End Sub

 Private Function setCam() As Boolean
        'Sets all the camera up
        If SendMessage(window_handle2, WM_CAP_DRIVER_CONNECT, 0, 0) Then
            SendMessage(window_handle2, WM_CAP_SET_PREVIEWRATE, 10, 0)
            SendMessage(window_handle2, WM_CAP_SET_PREVIEW, True, 0)
            isRunning = True
            Return True
        Else
            isRunning = False
            Return False
        End If
    End Function

On start button click the progress bar should start but it doesn`t it waits to display the image from the web cam and then to fill.

[xpda]

I don't see where the timer is enabled -- apprently when the button is clicked? You might try putting Application.DoEvents() right after the timer is enabled, and before the call to startcam.

[stoui333]

Why is still doesn`t work? Do i need to include something else?

Here`s how i activate timerProgreesBar

Private Sub strcam_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles strcam.Click
        TimerProgreesBar.Enabled = True
        Application.DoEvents()
                mycam.startCam(PictureBox1.Handle.ToInt32)
End sub

Here`s the timer

Private Sub TimerProgreesBar_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TimerProgreesBar.Tick

        If ProgressBar1.Value = ProgressBar1.Maximum Then
            ProgressBar1.Visible = False
            TimerProgreesBar.Enabled = False
        Else
            ProgressBar1.Value = ProgressBar1.Value + 10
        End If

    End Sub

The progress bar start when the web cam image appears in the picturebox, it stills waits the web cam to connected...

[Siddharth Rout]

This works for me... There is a part in the code which I haven't tried and I have indicated that...

Public Class Form1
    Private Sub btnGo_Click(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles btnGo.Click
        ProgressBar1.Step = 10
        ProgressBar1.Value = 0
        TimerProgreesBar.Enabled = True
        '~~> Haven't tried this part
        mycam.startCam (PictureBox1.Handle.ToInt32)
    End Sub
 
    Private Sub Timer1_Tick(ByVal sender As System.Object, _
    ByVal e As System.EventArgs) Handles Timer1.Tick
        ProgressBar1.PerformStep()
        If ProgressBar1.Value >= ProgressBar1.Maximum Then
            TimerProgreesBar.Enabled = False
        End If
    End Sub
End Class

[7777]

I said before I think your mainUI thread is blocked by the api calls, I could be wrong, through. Perhaps a hack it would probably be an easier solution than figuring out the multithreading, you could just use a animated gif make it visible before the call then set visibility to false after the call completes. Since your progress bar is not really measuring progress only time elapsed, I dont think that it really matters, as long as the user knows its "working"

google "ajax animated loading gif"