Visual Basic

Re: Add transparent border around image to make it larger

31-Jan-09 16:26

There are two possibilities. The first is that you don't need to add anything to the image. Depending on your requirements, you just do the math to center the image properly and draw it yourself. The second is that you create a bitmap object of the size required and, again, do the math to center the image and draw the image onto the new bitmap.

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Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

o m n i31-Jan-09 16:48

o m n i

31-Jan-09 16:48

Thanks creating a blank stretchec bitmap from a blank transparent png and drawing on it worked. Thanks for the help!

Re: Add transparent border around image to make it larger

Guffa1-Feb-09 13:16

Guffa

1-Feb-09 13:16

Omnicoder wrote:
creating a blank stretchec bitmap from a blank transparent png

Why would you do that? Just create a new empty bitmap...

Despite everything, the person most likely to be fooling you next is yourself.

Easiest method for form to change based on button clicked

sarmedic31-Jan-09 12:06

sarmedic

31-Jan-09 12:06

I have a data input form (Name, address, phone, etc) (Form2) that is launched from the main page (Form1). I want to use the same form for both add and edit functions - is there a way i can do something like this:

["Add New User" button pressed on Form1]
Form2.Show()
(Form2 Loads...)
If.....then...
btnAddNewUser.Visible = True
btnEditUser.Visible = False

basically, for Form2 to "know" what button was pressed on Form1, and change the buttons that are visible on Form2 based on Form1 input. Global variables? Or is there a function that will automatically do this?

Thanks!

Re: Easiest method for form to change based on button clicked

Christian Graus31-Jan-09 12:48

Christian Graus

31-Jan-09 12:48

sarmedic wrote:
basically, for Form2 to "know" what button was pressed on For

You have several options

sarmedic wrote:
Global variables?

This will work, but is nasty as hell

sarmedic wrote:
Or is there a function that will automatically do this?

No

The most obvious way to do this, is to pass a flag in to the constructor for your form, or if the same form is used over and over, then make it a property on the form. Why do you call Show and not Show Dialog ?

Christian Graus

Driven to the arms of OSX by Vista.

problems writing a program

mcmm31-Jan-09 11:16

mcmm

31-Jan-09 11:16

I am new to VB express 2008 express edition. I am working through some materials and am trying to design the form and write the coding to the following problem and am struggling greatly. Can anyone do it and I will work back from it and see where I am going wrong. I have one day to complete it.

A manager of a canteen want to write a program to calculate how much each customer has to pay. Memebers of staff are to pay VAT on their purchases but pupils do not. If the customer is a member of staff then the program will calaculate the VAT and add it to their total cost.

VAT is calculated using the formula.

VAT=0.175 * total cost

Their are 3 inputs in the program.
1 how many items the customer wants to buy,2
2 the price of each item and
3 whether the customer is a pupil or a member of staff (P for pupils and S for staff)

Output must display the total cost of the purchases, the type os customer, the amount of VAT paid and the final cost.

I would be really grateful if you could help me.

Thank you

Re: problems writing a program

Alan N31-Jan-09 12:21

Alan N

31-Jan-09 12:21

Oh dear, this really isn't a good first post for the Code Project forums. You shouldn't ask us to do your homework and you probably should have started it before now.

Can anyone do it and I will work back from it and see where I am going wrong.

It would be better if you let us see what you've done, if in fact you have done anything, and then we'll take it from there. Try to post specific questions with short code snippets that illustrate any problem you may be having.

Alan.

Re: problems writing a program

Christian Graus31-Jan-09 13:12

Christian Graus

31-Jan-09 13:12

This is incredibly easy. You should talk to your teacher if you're unable to understand how to do this. Someone doing this for you, is only going to mask your inability to do it, and further retard your progress in your class.

Christian Graus

Driven to the arms of OSX by Vista.

MS_ACCESS combobox filling.

ketan bader31-Jan-09 2:09

ketan bader

31-Jan-09 2:09

Hi all...
I am developing an application completely in MS_ACCESS. I have my project and the Access database at different locations e.g C:\ & D:\ resp.
Now i want to fill the combobox with two fields Srno, Name.

Help me how would I do it..
Thanks & Regards..

Re: MS_ACCESS combobox filling.

Henry Minute31-Jan-09 3:22

Henry Minute

31-Jan-09 3:22

If you are really just using MS_ACCESS, this question might get more response if you posted it in the 'General Database' forum.

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain

Girl: (staring) "Why do you need an icy cucumber?"

Programmatically controlling mouse.

the fossil31-Jan-09 1:42

31-Jan-09 1:42

Hi,

I would like to write a vb.net program that will programmatically position the mouse anywhere on the screen (not just the programs form) and then control the buttons and wheel. I.e. click on other applications.

Is this possible and can some please point me in the right direction.

Thanks,

Steve

Dave Kreskowiak31-Jan-09 16:23

31-Jan-09 16:23

Well, this isn't as easy as it would sound, but it is possible. The biggest problem is that control positions change along with the position of the windows you're clicking in. Also, directly controlling the mouse and simulating a click is not the way to go. You have to send the appropriate window messages to the control you're "clicking" on, without doing anything with the mouse. You have to get the handles of control windows (every control is a seperate window) to send these messages to. This means knowing the controls class type and name and how to find the correct control you want to click on.

You'd have to do research on FindWindow, SendMessage, various window messages, Windows Hooks, the CBT hook, message pumps, ...

Seriously, this is NOT a beginner level project. If you don't know this stuff, you're going to find it extremely difficult to do.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

the fossil1-Feb-09 4:02

1-Feb-09 4:02

Thanks for you reply.

Whilst I am a beginer in this topic I have actually been programming since the days of the ZX81 (~1981), all be it as a hobby and mostly self taught, I have come across the API's you mention before. Whilst it will be hard, if feel that with a little help pointing me in the right direction I ought to be able to manage it (if it's possible from within VB.net).

I do not want to acces any partucular control on any prticular form.

Rather I want to control mouse behaviour using an input device other than a mouse, if I can do it with a keyboard' I can do it with the controller I have in mind.

I have become disabled and am looking for a more effective way of interfacing with the computer than the conventional mouse and KB.

Thanks again

Steve.

Dave Kreskowiak1-Feb-09 6:36

1-Feb-09 6:36

the fossil wrote:
I do not want to acces any partucular control on any prticular form.

You don't really have a choice there. If not, you're just going to end up randomly clicking around the screen, not knowing what you're clicking on, if anything.

the fossil wrote:
Rather I want to control mouse behaviour using an input device other than a mouse, if I can do it with a keyboard' I can do it with the controller I have in mind.

That changes the question considerably. Normally, this stuff is done by writing a device driver. You're driver would have to take the hardware input and generate the appropriate mouse-equivilent messages. That is outside the relm of VB.NET or C#, but is squarely in the sights of Visual C++.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

the fossil1-Feb-09 7:16

1-Feb-09 7:16

Thanks,

That answers my question I had a feeling that would be the case but you can do so much more with vb.net now that I Thought it was worth asking the question.

Have you any idea about how I could go about getting such a device driver written?

Thanks again,

Steve.

Dave Kreskowiak1-Feb-09 11:20

Re: Programmatically controlling mouse. Partial answer

1-Feb-09 11:20

Device Drivers are more of a black art. For every 1000 people you find that can write a normal application, about 1 or 2 can do device driver work.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

the fossil2-Feb-09 9:25

2-Feb-09 9:25

It seems it ca be done, check this out-

http://forums.devx.com/showthread.php?p=516633#post516633[^]

Steve

Bharat Jain2-Feb-09 20:50

Bharat Jain

2-Feb-09 20:50

Hi Steve,
You are right , you can use mouse_even API to control the mouse movements , you can use the same API to control the click and scroll of the mouse ,following is an example to show you the use of this API

You don't require to write a device driver for it Smile | :)

I was try to answer this thread long , but got some error while posting , then it skipped of my mind Smile | :)

Sorry for that

This is the example to move the mouse

Public Class Form1
    Declare Auto Function mouse_event Lib "user32.dll" (ByVal dwflags As Integer, ByVal dx As Integer, ByVal dy As Integer, ByVal dwData As Integer, ByVal dwExtraInfo As Integer) As Integer
    Const MOUSEEVENTF_MOVE As Int32 = &H1 '  mouse move
    Const MOUSEEVENTF_LEFTDOWN As Int32 = &H2 '  left button down
    Const MOUSEEVENTF_LEFTUP As Int32 = &H4 '  left button up
    Const MOUSEEVENTF_RIGHTDOWN As Int32 = &H8 '  right button down
    Const MOUSEEVENTF_RIGHTUP As Int32 = &H10 '  right button up
    Const MOUSEEVENTF_MIDDLEDOWN As Int32 = &H20 '  middle button down
    Const MOUSEEVENTF_MIDDLEUP As Int32 = &H40 '  middle button up
    Const MOUSEEVENTF_ABSOLUTE As Int32 = &H8000 '  absolute move
    Const MOUSEEVENTF_WHEEL As Int32 = &H800 ' wheel button rolled
    Dim x As Int32 = 50
    Dim y As Int32 = 50
    Dim multiPlyfactorX = 65535 / Screen.PrimaryScreen.WorkingArea.Width
    Dim multiPlyfactory = 65535 / Screen.PrimaryScreen.WorkingArea.Height

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        mouse_event(MOUSEEVENTF_ABSOLUTE + MOUSEEVENTF_MOVE, x * multiPlyfactorX, y * multiPlyfactory, 0, 0)
        x = x + 1
        y = y + 1
    End Sub
End Class

Here you would have noticed that i have used two variable called multiPlyfactorX , multiPlyfactory. This is because the API takes 0,0 as left-top corner and 65535,65535 as right-bottom corner

also to send a click you can use the following code

mouse_event(MOUSEEVENTF_LEFTDOWN + MOUSEEVENTF_LEFTUP, x * multiPlyfactorX, y * multiPlyfactory, 0, 0)

Here x,y are the co-ordinates in pixcels

I hope this helps !!
I have to move now , let me know if you need any other help / information

-Regards
Bharat Jain
bharat.jain.nagpur@gmail.com

the fossil2-Feb-09 22:51

2-Feb-09 22:51

Presmably this will transfer the focus to the clicked window, this is fine in some instances but in others where I want to position the cursor brfore sending text this will be a problem. Can you think of a way of returning the focus to my app. after positioning the cursor.

Thanks,

Bharat Jain2-Feb-09 23:51

Bharat Jain

2-Feb-09 23:51

The control will be still with your application , just after sending the click command , write
Me.Activate()(i don't recommend its use)

this will activate your form , but if you have to enter any text in a different application the focus must be on the other application , not on your .

To make it more clear let us consider an example, if i have application "A" running it has a text box where we need to enter user name (without using a keyboard & mouse) , i will first position my mouse location on the text box (using the code i sent earlier) and we would send a mouse click (using the same code) just below the Mouse click code(now the focus is on other form (application "A")) we will write the code to send keystrokes (focus is on another form but your code will be executed , till your function ends), this keystroke would be sent to the form in focus (that is the form of application "A").

Also if you want to send keystrokes, you must use the Win32 API Called "keybd_event" defined in user32.dll , the same way we used mouse_event in previous reply.

does this make sense for you Smile | :)

-Regards
Bharat Jain
bharat.jain.nagpur@gmail.com

the fossil3-Feb-09 3:25

3-Feb-09 3:25

Thanks Bharat,

That's very clear.

I tend to use sendkeys.send rather than "keybd_event" it that OK?

Steve

the fossil3-Feb-09 3:40

3-Feb-09 3:40

I've come across another problem now.

I often use the forms topmost property, setting it to true, It has allways worked fine but now on this form it does not remain topmost. This happpens before any of the API's are called. Even just loading the form and moving away from that form causes it to be hidden. Any Ideas.

Thanks,

Steve

the fossil3-Feb-09 3:44