Combo boxes initially highlighted

[Gary Shell]

I have five comboboxes each has a item listed populated by hand in the IDE.
Each has the text property bound to a text field in the database. When I
initially fill the dataset and display the page all of these combo boxes
display the correct data, but all of them are highlighted as if they have
focus.

If I click in on and then click another control the highlight goes away. I
have a tabbed interface and If I navigate to another tab and back the
highlights are gone from all of the combo boxes.

How can I get them to initially display the data not highlighted?

Gary

[Gary Shell]

Well I think I finally found it. But I don't understand it! <big ol' grin>

I did a test where I removed the items collection from one of the
comboboxes. Then it still correctly displayed the data from my dataset, the
list portion of the combo box was empty as expected, but the text was not
highlighted!

I wondered if what I was seeing was an indication that the control was
telling me when it found a match between the dataset data shown and an item
in the list portion. To test that further, I replaced the items collection
but removed ONE item. Displaying various records in my database proved my
theory. Any time the data displayed had a matching item in the collection
the text was highlighted. Any time there was no match the text was not
highlighted.

I then realized that since I wanted to limit the user to pick ONLY from an
item in the collection, I should change the DropDownStyle property from
DropDown to DropDownList. When I did this and added the removed item back
to the collection, none of the displayed records produced a highlighted text
result!

This certainly is strange behavior though, I didn't try it here, but I am
pretty sure from other projects that if I had bound the datasource to a
table and set the displaymember, that a displayed record with a match in the
dataset bound item collection would NOT have resulted in highlighted text
even with the DropDownStyle set to the default DropDown value.

Gary
"Cor Ligthert" <no************ @planet.nl> wrote in message
news:us******** ******@tk2msftn gp13.phx.gbl...

Gary,

It was the code I expected (exactly as you described) however what would it do in your opinion.
(And therefore I asked you to show it, because I could misunderstand you).

The databinding is to set the text from the dataadapter field to the same
text in the combobox as is the currentposition in the datatable to what it
is binded. However that dataset has now in my opinion no way to change its
position.

What is your purpose now?

Cor

[Cor Ligthert]

Gary,

I have fight myself often with the combobox. In my (and I have seen in this
newsgroup not only my) opinion is it the most buggy control there is.

The expirience that you describe now, did I have as well. However I am still
not see how you bind it (It is not interesting to describe it, when you
found your solution it is OK).

Maybe is there something happening I never thought about, although I have
expirienced a lot with that combobox in the same way as you are doing now.

I am glad you are finding the solution.

Cor

[Gary Shell]

I do want to continue the discussion, even if I did find a solution, because
at some point it might be necessary to allow the user to enter an item not
in the item collection. In that case the DropDownStyle would HAVE to be
DropDown not DropDownList. And then I'm back to highlighted entries.

Here is the binding:

Me.cmbPartner.D ataBindings.Add (New System.Windows. Forms.Binding(" Text",
Me.datasetLocSc enario, "Scenario_to_Lo cation.PartnerT ype"))

Nothing fancy. Very straight forward.

I am not sure though if maybe the combobox is supposed to highlight the text
IF there is a match between the text portion and an item in the item
collection (the list portion of the combo). That may just be the intended
behavior. I say this because I do have another combo box on this same page,
it does have it's DataSource pointing to a dataset and uses the
DisplayMemeber and ValueMember. That one has a databinding from the forms
main dataset to the SelectedValue property. It has the same behavior when
its DropDownStyle is set to DropDown. The text is initially highlighted.
Setting that property to DropDownList and the highlight is gone.

Gary

"Cor Ligthert" <no************ @planet.nl> wrote in message
news:u4******** ******@TK2MSFTN GP15.phx.gbl...

Gary,

I have fight myself often with the combobox. In my (and I have seen in this newsgroup not only my) opinion is it the most buggy control there is.

The expirience that you describe now, did I have as well. However I am still not see how you bind it (It is not interesting to describe it, when you
found your solution it is OK).

Maybe is there something happening I never thought about, although I have
expirienced a lot with that combobox in the same way as you are doing now.

I am glad you are finding the solution.

Cor

[Cor Ligthert]

Gary,

What I did to test your behaviour was making a small test program.

Maybe can you look at that and change what is in your situation not the same
and try to get the behaviour you have, than we know both what it is.
(I did not change the style of the combobox yet in this)

\\\needs only 3 comboboxes on a form
Private Sub Form1_Load(ByVa l sender As _
System.Object, ByVal e As System.EventArg s) Handles MyBase.Load
Dim dt As New DataTable
Me.ComboBox1.It ems.AddRange(Ne w Object() _
{"1", "2", "3", "4", "5", "6"})
Me.ComboBox2.It ems.AddRange(Ne w Object() _
{"1", "2", "3", "4", "5", "6"})
Me.ComboBox3.It ems.AddRange(Ne w Object() _
{"1", "2", "3", "4", "5", "6"})
dt.Columns.Add( "Num")
For i As Integer = 0 To 5
dt.Rows.Add(dt. NewRow())
dt.Rows(i)(0) = (i + 1).ToString
Next
BindingContext( dt).Position = 1
ComboBox1.DataB indings.Add("Te xt", dt, "Num")
ComboBox2.DataB indings.Add("Te xt", dt, "Num")
ComboBox3.DataB indings.Add("Te xt", dt, "Num")
End Sub
///

[Gary Shell]

I loaded your code and of course it doesn't have the same behavior as mine.
<grin> or maybe it should be <sigh>

Now the question I have to answer myself is "what's different?".

I'll try to do that over the next few days but since the app is now working
with the other dropdown style and deadlines are looming close, it will have
to take a lower priority.

Thanks for you help. This is truly baffling, frustrating and highly
interesting all at the same time!

Gary

"Cor Ligthert" <no************ @planet.nl> wrote in message
news:%2******** ********@TK2MSF TNGP14.phx.gbl. ..

Gary,

What I did to test your behaviour was making a small test program.

Maybe can you look at that and change what is in your situation not the same and try to get the behaviour you have, than we know both what it is.
(I did not change the style of the combobox yet in this)

\\\needs only 3 comboboxes on a form
Private Sub Form1_Load(ByVa l sender As _
System.Object, ByVal e As System.EventArg s) Handles MyBase.Load
Dim dt As New DataTable
Me.ComboBox1.It ems.AddRange(Ne w Object() _
{"1", "2", "3", "4", "5", "6"})
Me.ComboBox2.It ems.AddRange(Ne w Object() _
{"1", "2", "3", "4", "5", "6"})
Me.ComboBox3.It ems.AddRange(Ne w Object() _
{"1", "2", "3", "4", "5", "6"})
dt.Columns.Add( "Num")
For i As Integer = 0 To 5
dt.Rows.Add(dt. NewRow())
dt.Rows(i)(0) = (i + 1).ToString
Next
BindingContext( dt).Position = 1
ComboBox1.DataB indings.Add("Te xt", dt, "Num")
ComboBox2.DataB indings.Add("Te xt", dt, "Num")
ComboBox3.DataB indings.Add("Te xt", dt, "Num")
End Sub
///