Label help in visual basic - Tilted Forum Project Discussion Community

mrpoopoohead · 12-15-2004, 05:43 PM

I was wondering how to make a label scroll across the screen like a marquee? it has something to do with x and y coordinates right? and i also wanted to know how to make it pop up and disappear in random places at random times

if anyone can help thanks a lot

Dilbert1234567 · 12-15-2004, 06:10 PM

you would have to do it manualy, with a timer or something

use a font that all the letters are the same width, count how many spaces it can desplay, create an array with the text (and fill the end of it with spaces) then cycle through it.

welshbyte · 12-15-2004, 06:11 PM

It would probably be easier to make the text inside the label scroll across. You would set the label to align right and then set up a timer up to add a character to the end of the string at each tick. Then when it gets to a certain length, start removing letters from the beginning of the string so it looks like its disappearing (and keeps your string small). Manipulating the string should be simpler and more efficient than manipulating a whole label control. Other than that, it's been a long time since i did any VB so i can't remember how the rest of the stuff you want to do would be accomplished.

a-j · 12-15-2004, 06:38 PM

This answer isn't really going to be specific to VB, but here are some problems you are bound to run into:

1) What do you mean by screen? Do you wan't the message to scroll across everything on the monitor (over other programs running, the taskbar, desktop, etc)? Do you just want to have text scroll across a vb window or dialog? If you were doing this in C you would be looking for the DC (device context) for the window (or desktop) you wanted to draw on. I assume you'll have to do the same for VB. Once you have the DC you want to draw on you can use basic text drawing functions to do the rest.

2) You are going to want to draw the text then erase it and draw it in a new place. If you don't care that the background gets erased (i.e. you are drawing on your own dialog/window, then you can probably do this easily. Otherwise you'll have to save the contents of what you overwrite and restore them, repeat ad nauseum.

3) You will no doubt see flicker in your application as the drawing, erasing goes. A better approach is to use double buffering -- erase and draw to something offscreen first and copy that data to the screen when you're done. This way you don't really erase what is on screen, you simply draw over it with the next iteration of what is offscreen.

4) Only erase/copy what you need, doing large block transfers (bitblt) can take a long time and there is no reason to draw over what you don't need to.

hrdwareguy · 12-16-2004, 07:11 AM

Just to add some additional thoughts:

I have done simular things simply by changing the Left property of the control. This will make it scroll across the screen/form.

As far as making it pop in random spots at random times, you can set the top and left properties for the position and set the visible property to determine if can be seen or not.

kebo · 12-16-2004, 12:25 PM

on a new form, put label1 then use the following code

Code:

Option Explicit

Const LABEL_WIDTH = 15 'characters
Dim j As Integer
Dim s As String
Private Sub Form_Load()
    s = Space$(LABEL_WIDTH) & "Have a great day" & Space$(LABEL_WIDTH)
    j = 1
    Timer1.Interval = 100
    Timer1.Enabled = True
    Me.Show
End Sub

Private Sub Timer1_Timer()

    Label1.Caption = Mid(s, j, LABEL_WIDTH)
    j = j + 1
    If j = Len(s) - LABEL_WIDTH - 1 Then j = 1
End Sub

for this to work correctly, you need to use fixed width font (like Courier) and you need to know how many characters wide the label is
HTH
kevin

12-15-2004, 05:43 PM	#1 (permalink)
mrpoopoohead Loser	Label help in visual basic I was wondering how to make a label scroll across the screen like a marquee? it has something to do with x and y coordinates right? and i also wanted to know how to make it pop up and disappear in random places at random times if anyone can help thanks a lot

12-15-2004, 06:10 PM	#2 (permalink)
Dilbert1234567 Devils Cabana Boy Location: Central Coast CA	you would have to do it manualy, with a timer or something use a font that all the letters are the same width, count how many spaces it can desplay, create an array with the text (and fill the end of it with spaces) then cycle through it. __________________ Donate Blood! "Love is not finding the perfect person, but learning to see an imperfect person perfectly." -Sam Keen

12-15-2004, 06:11 PM	#3 (permalink)
welshbyte Insane Location: Wales, UK, Europe, Earth, Milky Way, Universe	It would probably be easier to make the text inside the label scroll across. You would set the label to align right and then set up a timer up to add a character to the end of the string at each tick. Then when it gets to a certain length, start removing letters from the beginning of the string so it looks like its disappearing (and keeps your string small). Manipulating the string should be simpler and more efficient than manipulating a whole label control. Other than that, it's been a long time since i did any VB so i can't remember how the rest of the stuff you want to do would be accomplished. __________________ There are only two industries that refer to their customers as "users". - Edward Tufte

12-16-2004, 07:11 AM	#5 (permalink)
hrdwareguy "Officer, I was in fear for my life" Location: Oklahoma City	Just to add some additional thoughts: I have done simular things simply by changing the Left property of the control. This will make it scroll across the screen/form. As far as making it pop in random spots at random times, you can set the top and left properties for the position and set the visible property to determine if can be seen or not. __________________ Gun Control is hitting what you aim at Aim for the TFP, Donate Today

12-15-2004, 06:38 PM	#4 (permalink)
a-j Tilted	This answer isn't really going to be specific to VB, but here are some problems you are bound to run into: 1) What do you mean by screen? Do you wan't the message to scroll across everything on the monitor (over other programs running, the taskbar, desktop, etc)? Do you just want to have text scroll across a vb window or dialog? If you were doing this in C you would be looking for the DC (device context) for the window (or desktop) you wanted to draw on. I assume you'll have to do the same for VB. Once you have the DC you want to draw on you can use basic text drawing functions to do the rest. 2) You are going to want to draw the text then erase it and draw it in a new place. If you don't care that the background gets erased (i.e. you are drawing on your own dialog/window, then you can probably do this easily. Otherwise you'll have to save the contents of what you overwrite and restore them, repeat ad nauseum. 3) You will no doubt see flicker in your application as the drawing, erasing goes. A better approach is to use double buffering -- erase and draw to something offscreen first and copy that data to the screen when you're done. This way you don't really erase what is on screen, you simply draw over it with the next iteration of what is offscreen. 4) Only erase/copy what you need, doing large block transfers (bitblt) can take a long time and there is no reason to draw over what you don't need to.