Re: Visual Basic to generate a drawing - Visual Basic Discussion Boards

Getting Blank text value on Textbox Keypress [modified]

mdrizwan_111-Sep-09 20:59

11-Sep-09 20:59

Hello Everbody,

M getting a problem on textBox Keypress.When i pass 1st Character in textBox on keypress it takes textBox.text="" value.Can Anybody provide Solution to the problem please its menance bug.

Thanks in advance

Thanks Christian Graus

Problem [Solved]

modified on Saturday, September 12, 2009 3:45 AM

Re: Getting Blank text value on Textbox Keypress

Christian Graus11-Sep-09 21:08

Christian Graus

11-Sep-09 21:08

The keypress event allows you to block the text from going on to the textbox, Handle the keyup event instead, if you want the key's contents to already be reflected in the textboxes contents. It's not a bug, at all.

(edit) as I think about it, the textchanged event is the one you want, if you want to know when the text in the textbox changes.

Christian Graus

Driven to the arms of OSX by Vista.

Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.

Re: Getting Blank text value on Textbox Keypress

Abhishek Sur12-Sep-09 13:39

Abhishek Sur

12-Sep-09 13:39

use KeyUp event.
Keypreess fires just before the Text is changed. Rose | [Rose]

Abhishek Sur

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Visual Basic to generate a drawing

Member 419652111-Sep-09 18:31

Member 4196521

11-Sep-09 18:31

After scouring the net for info on using VB.net to generate graphic output, specifically a series of rectangles at mathematically derived intervals (a lattice, in fact), I'm now wondering if it's the best way to go. I've found nothing that demonstrates what I'm trying to do. I'm just starting out on a long, long road which I've been meaning to start on for a few years. I'd like to be able to create utilities as needed some day but wanted to start with this project to get going. Is VB (and GDI+) a bad choice for this type of work? I've made spreadsheets to do the math of laying out lattices but seeing them is just as important. Steer me in the right direction if there's a better way to go. I chose VB based on my thinking it's a relatively easy way to quickly get into programming.

Re: Visual Basic to generate a drawing

Christian Graus11-Sep-09 18:36

Christian Graus

11-Sep-09 18:36

Member 4196521 wrote:
Is VB (and GDI+) a bad choice for this type of work?

Not even remotely. It's the most trivial way I can see of doing it in a meaningful language. You just handle the paint event of your form, and you're passed a Graphics object. This object has methods for drawing shapes onto the form, using other objects like Brushes and Pens.

I think your best bet is to look at the MSDN for help on the Graphics object, I suspect that once you know that's where to look, you'll find that the documentation is going to lead you from there.

Christian Graus

Driven to the arms of OSX by Vista.

Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.

Re: Visual Basic to generate a drawing

Member 419652111-Sep-09 19:09

Member 4196521

11-Sep-09 19:09

Much obliged, Christian. Fears assuaged and whole bottle of eye drops at the ready. Once more unto the breach..

Re: Visual Basic to generate a drawing

Christian Graus11-Sep-09 19:18

Christian Graus

11-Sep-09 19:18

By all means, ask more specific questions if you still get stuck, but I think that's the boost you needed to get you on your way.

One thing, if you create any brushes, etc, they need to be disposed of, you call Dispose() on them, after using them. Using a system brush like Brushes.Black, does not have this requirement. Nor should you Dispose of the graphics object passed to you on the event args, although if you ever create your own, you should dispose of them, too.

Christian Graus

Driven to the arms of OSX by Vista.

Read my blog to find out how I've worked around bugs in Microsoft tools and frameworks.

Re: Visual Basic to generate a drawing

Member 419652111-Sep-09 20:50

Member 4196521

11-Sep-09 20:50

Uncanny timing, I had just read about 'dispose' on MSDN. Too soon to tell if I will be using a brush or coordinate points-to-lines to create filled rectangles : {, which may be far more work but seems to offer easier translation from the resultant calculations to be performed in determining spacing, typically to thousandths of inches to reduce accumulated error. The graphics don't require such precision, merely visual feedback, but no sense not using it if it's there I figure.

CRViewer Slow down my system

Adrian_Mia11-Sep-09 8:07

Adrian_Mia

11-Sep-09 8:07

Hello, I need help!!!
I have my application in visual studio 2008 (originally 2003). I use Access datbase and Cristal report Viewer to preview my reports. When I'm in the preview of a report, my whole system slow down really bad.
I have my database optimized and indexed
Any ideas what I can be doing wrong? if the problem is CR or Access.
Thanks!

Re: CRViewer Slow down my system

εїзεїзεїз11-Sep-09 8:16

εїзεїзεїз

11-Sep-09 8:16

well their could be alot of reason one can guess only in my opinion you might are passing your whole tables to cr and might then will be filtering using your selection criteria which is making it slower

Best Of Regards,
SOFTDEV
If you have knowledge, let others light their candles at it

Re: CRViewer Slow down my system

Adrian_Mia11-Sep-09 8:21

Adrian_Mia

11-Sep-09 8:21

Thanks for that fast answer.
The issuie is that the report shows up fast, but while the preview of the report (crviewer) is open the rest of the computers slow down, it sound to my like all the database were locked but not because it still working but slow.

Re: CRViewer Slow down my system

εїзεїзεїз11-Sep-09 10:28

εїзεїзεїз

11-Sep-09 10:28

try to use windows task manger and see which process is consuming more cpu and memory

Best Of Regards,
SOFTDEV
If you have knowledge, let others light their candles at it

Re: CRViewer Slow down my system

Adrian_Mia21-Sep-09 12:14

Adrian_Mia

21-Sep-09 12:14

I'll try it whan I go to my client office.
In the mean time we found out that if they leave a preview of the any report open and minimize they continue working normally, if you don’t have a preview screen open your computer start slowing down…that’s weird!

Mouse up event

RyJaBy11-Sep-09 5:13

RyJaBy

11-Sep-09 5:13

Hi,
Is there a way that you can check the state of the left mouse button inside a timer routine? I have a mouseup event but sometimes it seems like it doesn't go into the routine when i let go of the button.
Thanks

Re: Mouse up event

dan!sh 11-Sep-09 6:25

dan!sh

11-Sep-09 6:25

If you are having a handler then it should be executed when mouse up happens. Can you cite a scenario when it does not fires?

It's not necessary to be so stupid, either, but people manage it. - Christian Graus, 2009 AD

Re: Mouse up event

RyJaBy11-Sep-09 8:09

RyJaBy

11-Sep-09 8:09

I'm basically making my own slider.

Dim mouseheight As Integer
    Dim slidepos As Integer
    Dim handletop As Integer


    




    Private Sub sliderhandle_mousedown(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles sliderhandle.MouseDown
        handletop = sliderhandle.Top
        If MouseButtons = Windows.Forms.MouseButtons.Left Then
            SliderTimer.Enabled = True

        End If


        mouseheight = MousePosition.Y
    End Sub
    Private Sub sliderhandle_mouseup(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles sliderhandle.MouseUp
        SliderTimer.Enabled = False
        handletop = sliderhandle.Top


    End Sub


    Private Sub SliderTimer_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SliderTimer.Tick




      
        slidepos = handletop + MousePosition.Y - mouseheight


        If slidepos >= EmptyBar.Bottom - 15 Then
            sliderhandle.Top = EmptyBar.Bottom - 15


        ElseIf slidepos <= EmptyBar.Top Then
            sliderhandle.Top = EmptyBar.Top

        Else
            sliderhandle.Top = slidepos
        End If

endTimer:

    End Sub
End Class

So when i have the mouse down it is going through the timer routine and when i let go it should make sliderTimer.enabled = false
It works most of the time except for when i click and move the slider for a split second. Then what happens is it follows my mouse even though i do not have the button clicked. So i was thinking if i could check the mouse button state then i could force it to disable the timer.

Re: Mouse up event

Luc Pattyn11-Sep-09 8:23

Luc Pattyn

11-Sep-09 8:23

Hi,

Control.MouseButtons contains the instantaneous value you want.
if ((Control.MouseButtons & MouseButtons.Left)!=0) ... would be C# code, VB must be similar.

Smile | :)

Luc Pattyn

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Win7

cstrader23211-Sep-09 3:45

cstrader232

11-Sep-09 3:45

Sorry if this has been answered, but I couldn't find it.

I'm in VS2005 but using win7 as my os. There are problems resizing forms (strange flickers) and the new win7 "tricks" (for instance, dragging the window off the top to maximize) don't work. Do I need to recompile with VS2008 or is there another solution?

Thanks

Re: Win7

tosch11-Sep-09 3:53

tosch

11-Sep-09 3:53

Works for me just fine on Win7 Ultimate

Tosch

Re: Win7

cstrader23211-Sep-09 4:09

cstrader232

11-Sep-09 4:09

OK, thanks, I see that a simple form does work OK. So I have done something to my form that stops it from working. Any ideas?

Thanks again

Re: Win7

Eddy Vluggen11-Sep-09 4:45

Eddy Vluggen

11-Sep-09 4:45

Lots of code in the Form.Resize handler?

I are Troll Smile | :)

Re: Win7

cstrader23211-Sep-09 5:12

cstrader232

11-Sep-09 5:12

Nice guess, but no -- I don't even have the handler instantiated.

I tested the obvious stuff -- autoscalemode, autosize, etc, but it's not those either that I can tell.

Re: Win7

cstrader23211-Sep-09 6:47

cstrader232

11-Sep-09 6:47

OK, it's just the strange flashing that is what I think is a bug that only happens in Win7. Can anyone replicate this?

Add a horizontal splitcontainer to a form. Then run the program and resize the form from the lower right corner of the form. The form will flash larger then move back to it's correct size.

Thanks

Re: Win7 [modified]

DaveAuld11-Sep-09 9:50

DaveAuld

11-Sep-09 9:50

Have you played with the control property DoubleBuffered? does that make a difference? Also there are BeginUpdate and EndUpdate methods that can be used when populating controls to prevent/reduce flicker.

Dave
Who am I?: http://www.bebo.com/daveauld/
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modified on Friday, September 11, 2009 4:00 PM

Re: Win7

cstrader23211-Sep-09 15:47

cstrader232

11-Sep-09 15:47

It's not really flicker, it's erroneous drawing of the form on resize. You can see what I mean here:

http://www.cstrader.com/untitled/untitled.htm

Althouh it doesn't look like it on the video, the mouse that is dragging is actually in the corner of of the form

As the form resizes it snsps big, then snaps back to normal size.

The form has only a full-docked splitcontainer on it.

Only happens in win7.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.