Re: Constructor problems - Receiving T, need to indirect to a Constructor that accepts List(Of T) [modified] - Visual Basic Discussion Boards

helen00 wrote:
My.Computer.Keyboard.SendKeys("%( )X", True) 'ALT+SPACEBAR to restore minimize window

I'd avoid using SendKeys altogether. It's a bad method for controlling another application since the input focus can change to any window at ANY time. This includes the time between your call to SetForegroundWindow and the call to SendKeys.

Alt-Space, X closes the current window. It does not "restore minimize window".

helen00 wrote:
the notepad window stops at ALT+TAB

Your code doesn't mention anything about Alt-Tab.

Your should be using .NET classes and methods to do this. The Process class makes it a lot easier and you don't have to PInvoke any Win32 functions to do it.

A guide to posting questions on CodeProject[^]

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

Hi,

Thanks for your prompt reply.

Can you advise me sample codes of the better way to control another application? My whole objective of writing the program is to look for the Notepad window, graceful close the notepad via File > Exit and then restart the Notepad.

Your help and guidance will be greatly appreciate.

Regards

Dave is right, what you want to do is very fragile. But, there's no other way to control a program that doesn't expose a way of doing it. Your best bet is probably not to do it at all.

Christian Graus

Driven to the arms of OSX by Vista.

"I am new to programming world. I have been learning c# for about past four weeks. I am quite acquainted with the fundamentals of c#. Now I have to work on a project which converts given flat files to XML using the XML serialization method" - SK64 ( but the forums have stuff like this posted every day )

Christian is right. "Controlling" another app like this is VERY fragile and VERY easily broken. You have no way of keeping a known state, or knowing what happened when something goes wrong, and just about no way of correcting the situation, other than abandoning the entire process and closing all the apps involved and restarting the whole app.

Your code looks for a Notepad window, closes it and restarts Notepad?? To what end?? Why??

A guide to posting questions on CodeProject[^]

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

Public Sub New(ByVal type As LocationType, ByVal element As InspectionEntity)
    Me.New(type, New List(Of InspectionEntity){element})
End Sub
Public Sub New(ByVal type As LocationType, ByVal entities As List(Of InspectionEntity))
    Me.New(type, entities, New InspectionEntity([LIB].Enumerations.TableIDDefault.NullKey, "", ""))
End Sub

Ok...so here's the problem - One of my constructors accepts a singular "InspectionEntity" and I need to shove it into a List(Of InspectionEntity) so that it can be indirected to the next constructor in my chain (Only the terminal constructor sets properties on the object)

However, I am getting a squiggle beneath the '{' in {element}

Comma, ')', or a valid expression continuation expected.

Does anyone know the VB syntax to initialize the contents of a List(Of T) in-line?

"I need build Skynet. Plz send code"

Try this:

New List(Of InspectionEntity)(new InspectionEntity() {element})

10110011001111101010101000001000001101001010001010100000100000101000001000111100010110001011001011

Good call!

I tried

new List(Of InspectionEntity)(element)

but the compiler lied to me! lol...or at least that's my story and I'm sticking to it. My code above gave an InvalidCastException - Cannot convert type "InspectionEntity" to "IEnumerable"

When I altered it to be

new List(Of InspectionEntity)(new InspectionEntity(){element})

everything cleared itself out nicely.

"I need build Skynet. Plz send code"

Ok...never mind - I should have known:
The call to the constructor has to be like this:

Public Sub New(ByVal type As LocationType, ByVal element As InspectionEntity)
    Me.New(type, New List(Of InspectionEntity)(element))
End Sub
Public Sub New(ByVal type As LocationType, ByVal entities As List(Of InspectionEntity))
    Me.New(type, entities, New InspectionEntity([LIB].Enumerations.TableIDDefault.NullKey, "", ""))
End Sub

Note the parentheses surrounding "element" instead of curly braces...which would be the standard in every language OTHER than VB.

New problem though:

The element being passed in is null, and I get an ArgumentNullException saying that the list cannot be initialized with a null object. Anyone good enough with predicates that they could provide one that could initialize the list with element if !element.Equals(null) and suppress the initialization if the argument is null....I mean..."nothing"?

I'm pretty sure that an IIF will not work in this case, but please feel free to prove me wrong! Smile | :)

Update: I proved myself wrong! A chained IIF works...albeit wastefully since the true and false conditions must be evaluated, but it works

Public Sub Store(ByVal type As Location.LocationType, ByVal element As InspectionEntity)
'...
If Not typeAlreadyTracked Then
   'Theres no actual line-continuation '_' in my code. I only placed it here because the forum posts will not scroll horizontally.
   'The code is actually much more legible in a single line
Me._locations.Add(IIf((element Is Nothing), New Location(type), New Location(type, CType(_
 IIf element Is Nothing, New InspectionEntity(-999, "", ""), element), InspectionEntity))))
   typeAlreadyTracked = True
End If
End Sub

Both ternary conditions in the chain are the same check
I perform an IIF(element is nothing...) and another IIF(element is nothing...) within the transverse of the initial condition
(i.e. IIF(element is nothing) - "True of False" is a tautological impossibility because it requires element to be both null and !null at the same time; which essentially provides a true ternary evaluation (albeit with the computational slowdown of a full-scan evaluation)

"I need build Skynet. Plz send code"

modified on Monday, May 4, 2009 5:40 PM

btw...if anyone is interested in the whole constructor chain:

Public Sub New()
    Me.New(LocationType.NonDeterminant)
End Sub
Public Sub New(ByVal type As LocationType)
    Me.New(type, New List(Of InspectionEntity))
End Sub
Public Sub New(ByVal type As LocationType, ByVal element As InspectionEntity)
    Me.New(type, New List(Of InspectionEntity)(element))
End Sub
Public Sub New(ByVal type As LocationType, ByVal entities As List(Of InspectionEntity))
    Me.New(type, entities, New InspectionEntity([LIB].Enumerations.TableIDDefault.NullKey, "", ""))
End Sub
Public Sub New(ByVal location As Location)
    Me.New(location.Type, location.Entities, location.Selected)
End Sub
Public Sub New(ByVal type As LocationType, ByVal entities As List(Of InspectionEntity), ByVal selected As InspectionEntity)
    Me._type = type
    Me._entities = entities
    Me.setSelected = IIf(selected Is Nothing, New InspectionEntity([LIB].Enumerations.TableIDDefault.NullKey, "", ""), selected)
End Sub

"I need build Skynet. Plz send code"

--> i am having a problem with this code...

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
       If Not Me.TextBox1.Text = "a" Or Not Me.TextBox1.Text = "b" Then
           MsgBox("1")
       Else
           MsgBox("2")
       End If
   End Sub

--> this code always prints "1" in da message box..
--> what is the problem?

J A Nasir K

If TextBox1.Text is "a" then it is not "b", thus the first condition is fulfilled. The same for TextBox1.Text being "b". Any other value will also fulfill this condition.

You probably want to exclude both "a" AND "b".

10110011001111101010101000001000001101001010001010100000100000101000001000111100010110001011001011

<blockquote class="FQ"><div class="FQA">Jamal Abdul Nasir wrote:</div> Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
 If Not Me.TextBox1.Text = "a" And Not Me.TextBox1.Text = "b" Then            MsgBox("1")        Else            MsgBox("2")        End If    End Sub</blockquote>

Use And not Or

If it is not A and Not B then do something, else do something else.

------------------------------------

"Children today are tyrants. They contradict their parents, gobble their food and tyrannize their teachers. I despair for the future."
Socrates 400BC

Try to avoid "Not Logic". It is hard to read thus it can cause logic errors. Write you logic without the NOT operator and you will find it is much easier.

Try this condition

if me.textbox1.text = "a" or me.textbox1.text = "A" or me.textbox1.text = "b" or me.textbox1.text = "B" Then

MsgBox("2")
else

MsgBox("1")

end sub

This problem was solved hours ago. It's great you want to help people, but perhaps help people who still need help ?

Christian Graus

Driven to the arms of OSX by Vista.

"I am new to programming world. I have been learning c# for about past four weeks. I am quite acquainted with the fundamentals of c#. Now I have to work on a project which converts given flat files to XML using the XML serialization method" - SK64 ( but the forums have stuff like this posted every day )

On top of what Christian said, there are better ways of doing this than to make 4 conditions to check for 2 characters, while ignoring case.

A guide to posting questions on CodeProject[^]

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

How do I download the source code. When I open it in visual basic 2008 it's not working!? Sigh | :sigh:

What are you talking about?? What source code?? For what??

A guide to posting questions on CodeProject[^]

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

Congratulations. You're the stupidest person on these forums, at least today.

Christian Graus

Driven to the arms of OSX by Vista.

"I am new to programming world. I have been learning c# for about past four weeks. I am quite acquainted with the fundamentals of c#. Now I have to work on a project which converts given flat files to XML using the XML serialization method" - SK64 ( but the forums have stuff like this posted every day )

Rajesh B --> A Poor Workman Blames His Tools <--

:~I have a form that takes info from the user when all the entry is correct, the user can open another form for the next process.
What I mean is that let's say a registration form is open to create a registration record, when it's done, a complaint form is then open to create a complaint record based on the registration record. registration is a parent form and complaint is a child form.
the open registration record must be parsed to the complaint form for it to be opened.
the child form must be able to update the database and create a new record form its instance.

can anyone guide..

Best regard,
waner

Pass the 'registration' info from the parent form to the child form in the child forms constructor or property's (constructor is safest way since then you have to pass them)

Pseudo code:

class form1

private sub button1_click
'validate the registration info
if valid then 
dim frm as new form2(param1,param2,...)
frm.showdialog
end if
end sub

end class

class form2

public sub new (param1 as ..., param2 as ..., ...)
initializecomponent
'do more code here with the params
end sub

end class

thanks,

this is what I have done.

In the registration form that is the parent form

Private sub CreateAComplaint_Click

Dim row As IGRegistrationDataSet.RegistrationRow
row = CType(CType(Me.RegistrationBindingSource.Current, DataRowView).Row, IGRegistrationDataSet.RegistrationRow)

Dim frm As New ComplaintProfile(Me.IGRegistrationDataSet, row.Reg_ID)

frm.ShowDialog()

end sub

int the complaint form that is the child form, I have this

Sub New(ByVal ds As IGRegistrationDataSet, ByVal id As Integer)

' This call is required by the Windows Form Designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
Me.RegistrationBindingSource.DataSource = ds
Me.RegistrationBindingSource.Filter = "Reg_ID = " & id.ToString

End Sub
* One dataset and one table..
when save on the child form nothing happens to the data base, I must go back to the parent form for the changes to occur since the child form record is in memory. I want to update the database from both the parent and the child.

**I am open to use another logic where I use seperate datasets and tables so long the child form is open from the parent..
e.i. Registration record is fine then load the complaint form to create a complaint for this particular registration..

I hope I make myslef clear..

Thanks,

Best Regard

I have no clear answer, but I do have some comments to help you simplify what you are doing.

0) Use a BindingSource. See documentation and walk-throughs.

1) Just pass the row. There is no need for handling the data set then filtering or anything else. You can get to the table and data set from the row.

2) Manually bind to the row using a BindingSource. In some cases, it is easier to create a class to wrap the data row and handle the business rules.

3) When user clicks okay you may have to call row.AcceptChanges. This depends on how you data bind.

4) You may want to consider overriding the ShowDialog method as in ShowDialog(row As DataRow). Usually, it is easier because it allows you some setup and clean-up. For example, ...

Private _row As DataRow

Public Overloads Sub ShowDialog(ByVal row As DataRow)
    Dim iResult As DialogResult

    _row = row
    __bindingSource.DataSource = row

    _row.BeginEdit()
    'other setup

    iResult = MyBase.ShowDialog

    'clean-up
    If iResult = System.Windows.Forms.DialogResult.OK Then
        _row.AcceptChanges()
    Else
        _row.CancelEdit()
    End If

End Sub