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A common scenario is using controls made in VC++ and incorporated and nested
into a composite control in VB...
For example
FooActiveX-->VB Composite UserControl-->WrapperVB Control--->WindowsForm
In the past, I've read the recommendation is to bubble up events received by
FooActiveX --> WindowsForm.
But have found in practice, that this can be a maintenance nightmare come true.
For example you would have to raise events up in each one in the chain...
FooActiveX--(raise event)-->VB Composite UserControl--(raise event)-->WrapperVB Control---(raise event)-->WindowsForm
and worse is the reverse, when you have to communicate back downward by
calling and bubbling method calls downward
WindowsForm---(DoFooRefresh)-->WrapperVB Control--(DoFooRefresh)-->VB Composite UserControl-- (DoFooRefresh)-->FooActiveX
Is there a sane way to have your cake and eat it too? That is, to maintain
some kind of OO paradigm by making / using nicely encapsulated composite
ActiveX controls of this nature, without this messy chain messaging going
on?
ie....BROADCAST event, where only WindowsForm....will listen in and care
about event and the reverse, BROADCAST a message/command down
so ideally we would end up with these two instead
FooActiveX--(BROADCAST event)-->WindowsForm
WindowsForm---(BROADCAST command DoFooRefresh)-->FooActiveX
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 What property controls the initial visible default state of a datagrid?
My application fills a datagrid during form load from a oledb database query.
When the form is loaded the datagrid is blank except for a cell with a + sign
Once the + is clicked then a second cell is shown containing a link. After the link
is clicked the grid then is filled with the data.
How can I programmatically complete the first two clicks so that when the form is loaded
the user sees a full grid of data instead of having to click on the + and then on the link.
Thanks so much
Milancie
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Hi There
What does your code look like, if I use the following the grid immediately shows all the data
(I think it may be from using a DataTable or not?)
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim oDA As SqlClient.SqlDataAdapter
Dim oCon As SqlClient.SqlConnection = New SqlClient.SqlConnection
Dim oTBL As DataTable = New DataTable
oCon.ConnectionString = "Initial Catalog = Northwind;Data Source = (local);uid = sa;pwd=;"
Try
oCon.Open()
Catch ex As Exception
MessageBox.Show(ex.ToString)
End Try
oDA = New SqlClient.SqlDataAdapter("Select * from Customers", "Initial Catalog = Northwind;Data Source = (local);uid = sa;pwd=;")
oDA.Fill(oTBL)
Me.DataGrid1.DataSource = oTBL
End Sub
Regards
Peet Schultz
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Hello
I was able to show (load and show) a form , from inside a picturebox or frame in VB6.
I mean that, I could show a form named F2, inside a frame named fr which was placed on the form named F1.
There is a form named F1, there is a control (frame) placed on the form F1.
And I was able to show the F2 form inside the frame.
How can I do that in VB.NET ?
Thanks...
Best Regards
Emre YAZICI
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Hi Dears
I've to make a plug-in for MS Outlook. This plug-in will take a particular date, and will delete all the attchments of the e-mails which are older than that specific date.
Kindly guide me for the task. Provide/guide me some sample code if possible. I'll be very grateful to you.
Waiting for your kind response.
Atif
Watch Your Thoughts for they will become your actions.
Watch Your Actions for they will become your habits.
Watch Your Habits for they will become your beliefs.
Watch Your Beliefs for they will determine your destiny.
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I have a program on an XP box on a local network. I want to create a shortcut to that program on another machine. I can create the shortcut, but when the program starts, it brings up a debug screen and gives me a massage that says 'Invalid URL'. The debug window shows a NULL URL. I don't know why a URL is being requested, or how to prevent that from happening. I have a second program that I can successfully invoke from the second machine. One difference between the two programs is that the one that does not work references a dll that is part of the vb.net solution.
Any clues would be appreciated.
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How are you sharing the file? Have you put it in a shared directory?
Are the other boxes set up with user accounts on the XP box?
What path do you have in the shortcuts properties?
Can you see the file on the network?
Have you tried registering the DLL on the problem box?
Regards
Wayne Phipps
____________
Time is the greatest teacher... unfortunately, it kills all of its students
LearnVisualStudio.Net
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I have a project that has a RichTextBox that a user can enter data. The text box is called txtOut. I have a CommonDialog control and a command control called cmdSave with this code attached:
Private Sub cmdSave_Click()
Dim sFileName As String
sFileName = txtOut.Text '& theExtension
' Set CancelError is True
CommonDialog1.CancelError = True
On Error GoTo ErrHandler
' Set flags
CommonDialog1.Flags = cdlOFNHideReadOnly
' Set filters
CommonDialog1.Filter = "All Files (*.*)|*.*|Hex Files" & _
"(*.hex)|*.hex|Assembly Files (*.asm)|*.asm"
' Specify default filter
CommonDialog1.FilterIndex = 2
' Display the Open dialog box
CommonDialog1.ShowSave
' Display name of selected file
MsgBox CommonDialog1.FileName
Exit Sub
ErrHandler:
'User pressed the Cancel button
Exit Sub
End Sub
Everything works fine except after I name the file to be saved and hit the save button in the dialog window, it doesn't create the save file. I'm guessing it doesn't see the data in the text box. Can someone give me some help please? Thanks!
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It's because the CommonDialogs only display dialogs to gather information from the user. So the Open, Save and Print dialogs don't actually do the opening, saving or printing for you. You have to implement that yourself. So in your case you have to check that the user has succesfully OKed a filename and then use something like a StreamWriter to save your file.
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I am not an experienced coder, is there sample code or information available on how to do that?
Thanks!
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Here's something I've done in the past, you should be able to pull it apart for your own stuff:
Private Sub SaveINIFile()<br />
Dim strCurrentSection As String<br />
Dim ptrRecord As INILayout<br />
<br />
If strFileName = "" Then Return<br />
<br />
ptrFileWriter = New System.IO.StreamWriter(strFileName)<br />
<br />
For Each strCurrentSection In colINISections<br />
ptrFileWriter.WriteLine("[" & strCurrentSection & "]")<br />
For Each ptrRecord In colINIEntries<br />
If ptrRecord.strSection = strCurrentSection Then<br />
ptrFileWriter.WriteLine(ptrRecord.strHeader & "=" & ptrRecord.strValue)<br />
End If<br />
Next<br />
Next<br />
<br />
ptrFileWriter.Close()<br />
End Sub
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It's quite simple
Open CommonDialog1.FileName For Output As #1
Print #1, "Hello!"
Print #1, "Green is Purple"
Print #1, "--------"
Print #1, Text1.Text
Close #1 HTH
=====
Phlip
Always proofread carefully to see if you any words out
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Thanks to everyone for their help! This is what I ended up using:
Private Sub cmdSave_Click() 'When users clicks Save
'note: the entire file is stored in a string
CommonDialog1.Filter = "Hex files (*.HEX)|*.HEX"
CommonDialog1.ShowSave 'display Save dialog
If CommonDialog1.FileName <> "" Then
Open CommonDialog1.FileName For Output As #1
Print #1, txtOut.Text 'save string to file
Close #1 'close file
End If
End Sub
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I'm trying to get my Data Access classes to provide a Bind method to allow a member variable to be bound to a control, such as a textbox:
Customer.Bind( TextBox1, Customer.m_strUserName )
Inside the Bind method, I'm adding my own eventhandler to the control, and attempting to store the references to the control and the passed member variable into a collection, so this way many controls can be bound against the classes member variables:
Public Sub Bind( ByRef ptrControl as System.Windows.Forms.TextBox, ByRef ptrMember as Object )<br />
<br />
AddHandler ptrControl.KeyPress, AddressOf ConsumeKeyPress<br />
<br />
Dim ptrElement as new ControlCollectionGroup()<br />
ptrElement.ptrControl = ptrControl<br />
ptrElement.ptrMember = ptrMember.Clone()<br />
colControls.Add( ptrElement )<br />
End Sub
Where the type being added into the collection is defined as:
Structure ControlColelctionsGroup<br />
Public ptrElement as System.Windows.Forms.TextBox<br />
Public ptrMember as Object<br />
End Structure
Now the problem is to do with the references being passed for the control and member variable. When they are passed into Bind() as references, they work, and the code can access the original control and variable as you would expect.
After this stage, when the references are passed to an element in a collection, or just stored within normal types within the class - the reference seems to disappear - and I get copies of the textbox and the member object instead. This then renders the whole thing useless as I need to be able to exchange data between the control and the member variable whenever a keypress takes place.
So is there a most learned VB.NETter that can help me with these questions:
1. Can I reference a reference?
2. Is there something similar to StrPtr() I can use which was dropped after VB6.
3. Is there a better way of binding a control to a member variable?
Thanks for reading this novel.
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TextBox and Object are reference types. You should pass a reference type ByVal unless you need to change what the reference points to inside the called function. I can't think of a reason offhand.
If you want to keep referring to the same object within your collection, you shouldn't use Clone. That's for making a copy of the remote object.
This kind of thing is best dealt with using diagrams, unfortunately. I'll try with words.
Say you call Bind like so:
Bind( TextBox1, m_oData1 ) TextBox1 isn't actually the text box itself: it's just a reference to the text box. If, inside Sub Bind, you had the statement:
ptrControl = TextBox2 the field TextBox1 would now refer to the same control as TextBox2.
In your code, when you use
ptrElement.ptrMember = ptrMember.Clone() that makes a new object which is a copy of the object referred to by ptrMember, then sets ptrElement.ptrMember to point to the new object. There's no link between this object and the original ptrMember.
I think your implementation will work if it looks more like:
Public Sub Bind( ByVal ptrControl as System.Windows.Forms.TextBox, ByVal ptrMember as Object )
AddHandler ptrControl.KeyPress, AddressOf ConsumeKeyPress
Dim ptrElement As New ControlCollectionGroup()
ptrElement.ptrControl = ptrControl
ptrElement.ptrMember = ptrMember
colControls.Add( ptrElement )
End Sub Hope this helps.
Personally I find reference languages to be more, not less, confusing than languages with explicit pointers. I can follow explicit pointers because it's obvious - to me - what's happening.
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Thanks for your suggestion, but unfortunately the references are still lost, and it would appear when the control and object are passed into the collection, they are passed copies.
Sorry for leading you up the garden path by using that .Clone(), I was experimenting in the code - needless to say that didn't work.
Anyhows, have implemented exactly what you specified, and the behaviour suggests that you cannot have a reference to a reference!!!
In the good old days when I were but a young lad, and sweets were a penny each, and mobile phones were the size of a house, I could just use StrPtr(), but this feature has been ripped out of .NET...........
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I am looking for some help regarding using the speech recogntion (DirectSR).
Anyone with some idea can help. WOuld be useful for others in a similsr situation.
S.Seetharaman.Iyer
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OK. What are you looking for help with?
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Hi. I have three simple C# classes that I would like ported to VB.NET. If anyone would be willing to take a look, I'd appreciate it. Please let me know. There is no pay. But you will, of course, receive credit...and gratitude.
Thanks.
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I'll give it a try.
Bo Hunter
bovsnet@msn.com
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I'll do it.
Mail them to wcoonrod@visi.com
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Does anybody know, how to import data from microsoft Project Planner
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I myself found something on MSDN that I can get object of MSPRJ9.obl. And then I can create object MPP. But anybody knows is that Object Library is distributable.
Regards,
Samya
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Hello,
I was wondering about how am I able to show another Form object from vb.net? Also how can I access of modify a property of an object
e.g.:
Form2.Text1.Text = "testing"
Thanks
Best Regards
Emre YAZICI
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This should work:
You have to create an instance of the other form before you can change properties on it.
Dim otherForm As New Form2()
otherForm.Show()
otherForm.TextBox1.Text = "hello"
Beware the chickens, for in their silence, they plot...
Life is too short to be taken seriously.
-- Oscar Wilde
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