Visual Basic

Re: Link progress bar to a timer

3-Mar-07 6:44

A Progressbar doesn't progress on it's own. Your code has to actively update the current value of the ProgressBar control to get the bar to move. This means that you can't just set a Timer for 5 seconds, sit back and do nothing until it fires. Your Timer has to advance the ProgressBar.

Setup a ProgressBar on your form. Set it's minimum value to 1, maximum to 10, and step value to 1. Set a Timer on your form for say 500 milliseconds (half a second). In the Tick event of your Timer, call the PerformStep method on the Progress bar. When the Value of the ProgressBar reaches 10, your done, close your form.

Docs on ProgressBar[^]

Dave Kreskowiak
Microsoft MVP - Visual Basic

harveyhanson3-Mar-07 7:12

harveyhanson

3-Mar-07 7:12

Nice one, sorted Smile | :)

Call Keypress

Anybloodyid3-Mar-07 5:14

Anybloodyid

3-Mar-07 5:14

Below is what I have in the frmMain_KeyDown event
How do I call it from the Timer1_Tick event?

Dim strKeyPress As String = Nothing
        strKeyPress = e.KeyCode.ToString()

        Select Case strKeyPress
            Case "Left"
                R.X -= 10
            Case "Right"
                R.X += 10
        End Select

JUNEYT3-Mar-07 5:32

JUNEYT

3-Mar-07 5:32

You should examine EventHandler and RiseEvent methods. You can rise the event inside the Timer1_Tick event. WTF | :WTF:

What a curious mind needs to discover knowledge is noting else than a pin-hole.

Dave Kreskowiak3-Mar-07 6:37

3-Mar-07 6:37

You move this code to it's own method, then call it from the KeyDown event handler, passing the data the method needs to do its work. You do the same from your Tick event handler, but why are you calling keyboard handling code from a Timer?? And why are you converting the Keycode to a String when you don't have to??

Private Sub KeyHandler(ByVal keyCode As Keys)
    Select Case keyCode
        Case Keys.Left
            R.X -= 10
        Case Keys.Right
            R.X += 10
    End Select
End Sub

From your KeyDown event handler, you just do:

KeyHandler(e.KeyCode)

From your Tick event handler, you have to pass in whatever keycode you're going to use:

KeyHandler(Keys.Left)

Dave Kreskowiak
Microsoft MVP - Visual Basic

Anybloodyid3-Mar-07 10:55

Anybloodyid

3-Mar-07 10:55

Hi Dave,
I'm just messing with an image that is divided into 35 Squares one is picked at random then the Timer1 event fires and drops the square down the form, what I want to do is press the left or right arrow key and move the tile accordingly.
So I need to check throughout the timer event to see if the arrow keys have been pressed or not.

Dave Kreskowiak3-Mar-07 13:14

3-Mar-07 13:14

Your tile coordinates would probably have class scope. This mean you can get to the coordinates from any method in your form.

Your Timer event should just be concerned with changing the coordinates, moving the tile down the form. It doesn't need to know anything about any keystrokes and doesn't need to generate any.

The second thing that the Timer event needs to do is redraw the form so the user sees the tile moving down the form.

Your keydown event should be doing just what it's doing - moving the tile coordinates left and right.

Dave Kreskowiak
Microsoft MVP - Visual Basic

VB.net and GetForegroundWindow Issues/Bug???

Anybloodyid3-Mar-07 22:08

Anybloodyid

3-Mar-07 22:08

Cheers Dave Smile | :)

brentleim13-Mar-07 4:58

3-Mar-07 4:58

Hi,

I am attempting to make and application that retrieves information about the active window in the system. I have always used the GetForegroundWindow function with no problems in both C++ and VB6.

However, when I attempt the call the function in VS2005, vb.net, I only return the window handle about a third of the time. The other two thirds it simply returns 0. The window type doesnt seem to matter since it has happened with many different windows.

This is my code for attempting to retrieve the hwnd...

Dim lhwnd As Long

Call ShowWindow(Me.Handle), SW_HIDE)
lhwnd = GetForegroundWindow
Me.Text = lhwnd
Call ShowWindow(Me.Handle, SW_SHOW)

I have tried it using command buttons, link labels and other control click events and it still doesnt seem to want to work.

I tried calling it as such also.

Dim lhwnd As Long

Call ShowWindow(Me.Handle), SW_HIDE)
Dim lhwnd as long = GetForegroundWindow
Me.Text = lhwnd
Call ShowWindow(Me.Handle, SW_SHOW)

and

Dim lhwnd As Int32

Call ShowWindow(Me.Handle), SW_HIDE)
lhwnd = GetForegroundWindow
Me.Text = lhwnd
Call ShowWindow(Me.Handle, SW_SHOW)

Although it doesnt show, i also even placed the application.doevent call inbetween each line but that did not help either...

any help can be appreciated...

Thank You,

Brent

Dave Kreskowiak3-Mar-07 6:25

Re: VB.net and GetForegroundWindow Issues/Bug??? [modified]

3-Mar-07 6:25

We need to see the Declaration of the GetForgroundWindow function. I get the feeling you just used the VB6 code without any conversion. The problem most people run into is that they don't know the difference between a VB6 Long type and a VB.NET Long.

In VB6, a Long is a standard 32-bit signed integer. In VB.NET, Long is a 64-bit signed integer. A VERY different number with different storage requirements.

For handles, you should be using the IntPtr type in VB.NET. So, for GetForegroundWindow, the Declare should be:

    Private Declare Auto Function GetForegroundWindow Lib "user32" () As IntPtr
.
.
.
    Dim foreWndHandle As IntPtr = GetForegroundWindow()

Dave Kreskowiak
Microsoft MVP - Visual Basic

brentleim13-Mar-07 8:20

3-Mar-07 8:20

Ok, I did not have the correct declaration but then I put your code in and i still only get back 0 every time for the hwnd...

here it is...

Public Declare Auto Function GetForegroundWindow Lib "user32" () As IntPtr<br />
<br />
<br />
Dim foreWndHandle As IntPtr = GetForegroundWindow()<br />
Debug.Print(foreWndHandle)<br />
<br />

I just debug.print it for ease of seeing if a viable hwnd pointer is returned. I get only about 10% of the time whether its a long, a int32 or intptr...

If i set it to int64, then i get a return everytime but i also get overflow which is understandable... now if there is a way to convert the 64-bit integer to a 32-Bit maybe it will work... I dont know...

I dont know why, but it pretty much only happens when the form is minimize or not visible. If the form is visible and the code is put into a timer to get the window, it gets it no problem.

<br />
    Private Sub Timer1_Tick_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick<br />
        ListBox1.Items.Add(GetForegroundWindow)<br />
    End Sub<br />

I swap other windows to the foreground and their hwnds are captured with no probem, but when I minimize or make non visible, the function cannot retrieve the foreground window handle.

Brent

-- modified at 15:25 Saturday 3rd March, 2007

Dave Kreskowiak3-Mar-07 10:29

3-Mar-07 10:29

On a 32-bit processor, GetForegroundWindow will return a 32-bit unsigned integer, guaranteed. Using a 64-bit interger just corrupts the stack, so don't do it, unless, of course, you're running 64-bit Windows. If you have to ask how you can tell which version your running, your running 32-bit.

GetForegroundWindow CAN return 0, such as, how you've found, when a window is losing it's activation, like when you minimize the foreground window or its no longer visible. This is normal operation as described in the documentation for GetForegroundWindow[^].

Dave Kreskowiak
Microsoft MVP - Visual Basic

brentleim13-Mar-07 10:56

3-Mar-07 10:56

Right, and I understand that. However, when I do it in VB6 i have absolutely no problem with capturing the handle by placing a doevents between the minimize/visible call and the GetForegroundWindow call.

I tried application.doevents but it didnt seem to work either.

Does anyone think that calling the waitforsingleobject api call may work in this case, or what is the api call for a doevents.

By the way, thanks for helping me. The swap from VB6 to .net is a slow one.

Brent

brentleim13-Mar-07 12:43

3-Mar-07 12:43

I finally made a workaround, and i hate workarounds but here it is unless someone else has a better idea...

  <br />
Do<br />
     wndHWND = (GetForegroundWindow)<br />
     Application.DoEvents<br />
Loop Until wndHWND <> 0<br />

I works but man I hate looping just to get a value..

Brent

Dave Kreskowiak3-Mar-07 13:29

3-Mar-07 13:29

Well, you have to account for the fact that, sometimes, there is no ForegroundWindow!

Dave Kreskowiak
Microsoft MVP - Visual Basic

Dave Kreskowiak3-Mar-07 13:26