This is irritating.

[Troy Lundin]

I am about as irritated as I can get with this project. I have posted questions about it before and have tried every suggestion thrown my way. But, the program still refuses to work.

I have attached the source files. If somebody could please take the time to look at my project and find out why it doesn't work.

Here is what you do to test the program. Make sure Notepad is open, then start my program. Clicking on the top button is supposed to write a value at a certain address but instead it does nothing and if you look at the immediate window it shows the error. Click the Debug button will show you info about the process.

If you can get it to work then please attach a copy of the working source. I have a feeling that if just the corrections are posted and I try to implement them it still won't work.

I have no idea why this is not working. I just hope it isn't my computer. Thank you to anybody that helps.

[rory]

For starters.

You should use Option Explicit in the form

And This: (causes error)

For Each Form In Forms
If Not Form Is Me Then Unload (Form)
Next Form

Should be this:

Dim i as Integer
For i = Forms.Count - 1 To 1 Step -1
Unload Forms(i)
Next

[Troy Lundin]

Thank you for that tip rory. The unload code was actually suggested by a member of these here forums.

Did you get a look at the 487 error?

[rory]

yeah checking that now ..

note the Dim i above i'd forgotten ..

[Shuja Ali]

And This: (causes error)

For Each Form In Forms
If Not Form Is Me Then Unload (Form)
Next Form

Should be this:

Dim i as Integer
For i = Forms.Count - 1 To 1 Step -1
Unload Forms(i)
Next

Why would it cause any error? I have been using this code for years now. Is there any specific reason why we shouldn't be using this code?

[rory]

Why would it cause any error? I have been using this code for years now. Is there any specific reason why we shouldn't be using this code?

Can do, just in his case Form is not Declared.
The way i listed is the method suggested by MS.

[bushmobile]

The way i listed is the method suggested by MS.

Got a link for that?

Most of the people here will be using the For...Each loop (with the form object correctly declared)

You may end up trying to unload a form that no longer exists if you use the method you've suggested.

[rory]

Got a link for that?

Most of the people here will be using the For...Each loop (with the form object correctly declared)

You may end up trying to unload a form that no longer exists if you use the method you've suggested.

Just use MS Application Wizard .. also works in apps I have with many forms loaded or unloaded ...

[rory]

Anyways back to the topic ..

Error 487:
Attempt to access invalid address.

Are you setting the correct address to write to?

[Shuja Ali]

Can do, just in his case Form is not Declared.
The way i listed is the method suggested by MS.

While looping through a collection MS has always recommended using For Each Loop. As Forms is basically a collection so using a For Each loop will be way better that using For i=0 to something loop.

My question was are there any drawbacks of using For Each loop to unload the Forms?

[rory]

While looping through a collection MS has always recommended using For Each Loop. As Forms is basically a collection so using a For Each loop will be way better that using For i=0 to something loop.

My question was are there any drawbacks of using For Each loop to unload the Forms?

Dont think there is, but like I said, thats what Microsoft uses in their VB6 application Wizard so thats what I use.

[bushmobile]

MS Application Wizard <> Best Programming practice

If one of the forms you unload from the For i = 0 to... loop unloads an, as yet, unloaded form, then the number of items in the forms collection will not match the number in the loop and you'll get a subscript out of range error.

that doesn't happen with a for each loop

[rory]

MS Application Wizard <> Best Programming practice

If one of the forms you unload from the For i = 0 to... loop unloads an, as yet, unloaded form, then the number of items in the forms collection will not match the number in the loop and you'll get a subscript out of range error.

that doesn't happen with a for each loop

You would get the error with this:

For i = o To Forms.Count
Unload Forms(i)
Next

But not this:

For i = Forms.Count - 1 To 1 Step -1
Unload Forms(i)
Next

see attached example ...

[Shuja Ali]

Dont think there is, but like I said, thats what Microsoft uses in their VB6 application Wizard so thats what I use.

Anyways, so the suggestion from my side is that you should be using a For Each loop when dealing with collections (not just Forms collections, an collection for that matter). It is quicker and safer.

[bushmobile]

Add three forms:

' In Form1
Option Explicit
 
Private Sub Form_Load()
    Form2.Show
    Form3.Show
End Sub
 
Private Sub Form_Unload(Cancel As Integer)
    Dim i As Integer
    For i = Forms.Count - 1 To 1 Step -1
        Unload Forms(i)
    Next
End Sub
 
' In Form3:
Private Sub Form_Unload(Cancel As Integer)
    Unload Form2
End Sub

Run the code and close Form1

[Troy Lundin]

It seems like we are getting ouselves a tangent here.

Now, my question had nothing to do with the method I use to unload my form (of which I only have 1 at the moment), it has to do with the error I am getting (error 487). Why am I getting it? And, how can I get this program to work?

Thank you.

[rory]

Run the code and close Form1

Yep your'e right there .. oh well ..i never unload forms like that so didnt know .. Im emailing MS right now those ...Uhumm ..

But doesnt appear to need that Is me part ..?

Do Until Forms.Count = 1
    Unload Forms(Forms.Count - 1)
Loop
 
Or ..
 
Dim Form
For Each Form In Forms
    Unload (Form)
Next Form

back to the topic .. how are you getting the address .. the error is the Address is Invalid ..

[noshaba]

i have executed ur program and find rcvd no error and in immediate window it is displaying 87...........either i couldn't understand it ir something else is there

[Troy Lundin]

I got the address using a program called TSearch which let's me search a process and find offsets of interest. The address is actually for a game called Oasis, but even if you change the address to any value it gives that same error.

Believe it or not I actually had this program working about a week ago. I didn't even change much and all of the sudden it doesn't work. There has to be a reason.

By the way, the error is error 487, not 87, noshaba.

[Al42]

Try, I haven't looked at your program, but are you trying to access memory owned by another process?

[Troy Lundin]

Yes the memory I am accessing belongs to a game. The thing is that I had this working and the buttons did what they were supposed (as fas as changing the values of the offsets). All the sudden it stopped working. And I have no idea why.

[rory]

wouldnt the memory address change from one PC to the next?
I Dont know much about memory allocation, just curious ..

Also, wouldnt the address you have for the game be different for Notepad?

[moeur]

I think that the problem is that the memory address you are trying to access is locked to you. You are not guaranteed that any arbitrary memory address is accessable. Does it give you the same error when you try it on the game?

if you try to read the memory do you get the correct values?

One way to test your reading and writing routines is to allocate some memory in the other process first then read to and write from it.

See post #30 in this thread for an example that gets listview items from external programs by allocating memory in the external process space, writing to that memory, sending a Get item text message and then reading from the external space to retrieve the values returned by the message. This is necessary becaue listview messages are not marshalled by the operating system between processes.

http://www.vbforums.com/showthread.p...0&page=1&pp=40

[Troy Lundin]

Ok, I ran the program in your post(#30) and entered the window handle of the game window into the textbox and clicked the button. A msgbox came up that said: 0 (&H0): The operation competed successfully.

Then i click ok button and the debugger comes up with the following line highlighted:

'send the get the item message
    strLength = SendMessage(hWindow, LVM_GETITEMTEXT, iItem, ByVal pMyItemMemory)
    If strLength = 0 Then
        MsgBox GetAPIErrorText(Err.LastDllError)
        Stop '<-- this line is highlighted
    End If

When i continue the program a msgbox pops up with no message.
Does this mean that writing to the process was successful?

[Troy Lundin]

Ok, this takes the cake.

I have attached another project. It is the bones on which I based my program. And get this: It works!

Now, can somebody tell me why this one works but mine doesn't.