Updating the form's fields

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Hi All!

I am with a situation where I am not getting the right updating to the
form's fields. The situation is the following one:

I have one combobox and one textbox. I am using the CurrentChanged event of
the BindingSource of the combobox to update the textbox. When selecting an
item in the combobox or when selecting a row in the grid, it is updating the
textbox correctly. The problem is when I apply a filter in the grid, and then
the grid has no rows. I already made the following attempts:

- When there is no row in the grid, the event is not called, and textbox
mantains the previous content;
- If I call the CurrentChanged event directly when there is no rows in the
grid, in this case I clean up the textbox, but when I apply a filter again in
the grid and the position of the combobox does not modify (that is, it is in
the same register), the CurrentChanged is not called, and edit is blank
(because I cleaned before);
- I already tried to use “combo.Select edIndex = -1” but also did not worked.

Does someone has any idea of how can I solve this situation?

Thank you for any suggestion!
Vanessa

[=?Utf-8?B?TW9ydGVuIFdlbm5ldmlrIFtDIyBNVlBd?=]

RE: Updating the form's fields

Hi Vanessa,

I suspect you get some invalid data breaking the databinding. Try handling
the DataError event of the BindingSource.

It is a bit unclear what you have databound and not, and in fact what
controls you have. What is the relationship between the (data)grid and the
combobox? Are you databinding a ComboBox to one BindingSource and a DataGrid
to another, while the TextBox remains unbound and is updated manually when a
change occurs in either the ComboBox or the DataGrid?

Other things to try. Bind the TextBox to the same BindingSource as the
ComboBox rather than updating it in the CurrentChanged event (although this
won't work if you use the same TextBox to display values from another
BindingSource as well). Try handling the ListChanged event, which should
fire if the underlying datasource changes. If the list is changed, get the
BindingSource.C urrent value and update the TextBox accordingly.



--
Happy Coding!
Morten Wennevik [C# MVP]


"Vanessa" wrote:

Hi All!
>
I am with a situation where I am not getting the right updating to the
form's fields. The situation is the following one:
>
I have one combobox and one textbox. I am using the CurrentChanged event of
the BindingSource of the combobox to update the textbox. When selecting an
item in the combobox or when selecting a row in the grid, it is updating the
textbox correctly. The problem is when I apply a filter in the grid, and then
the grid has no rows. I already made the following attempts:
>
- When there is no row in the grid, the event is not called, and textbox
mantains the previous content;
- If I call the CurrentChanged event directly when there is no rows in the
grid, in this case I clean up the textbox, but when I apply a filter again in
the grid and the position of the combobox does not modify (that is, it is in
the same register), the CurrentChanged is not called, and edit is blank
(because I cleaned before);
- I already tried to use “combo.Select edIndex = -1” but also did not worked.
>
Does someone has any idea of how can I solve this situation?
>
Thank you for any suggestion!
Vanessa

[=?Utf-8?B?VmFuZXNzYQ==?=]

RE: Updating the form's fields

Hi Morten!

Let me explain better what I want to do.

My database has the following tables:

Table A - the main table that is shown in the form. It has a field that is a
key into Table B;
Table B - it is related to Table A and it is a combobox in the form. It has
a field that is a key into Table C;
Table C - it is related to Table B and it has a description field to show in
a textbox.

So, my question is, how can I make the binding to the textbox that is on
Table C? What I want is to show the description field from Table C, whose key
is on the Table B (combobox).

Thank you,
Vanessa

"Morten Wennevik [C# MVP]" wrote:

Hi Vanessa,
>
I suspect you get some invalid data breaking the databinding. Try handling
the DataError event of the BindingSource.
>
It is a bit unclear what you have databound and not, and in fact what
controls you have. What is the relationship between the (data)grid and the
combobox? Are you databinding a ComboBox to one BindingSource and a DataGrid
to another, while the TextBox remains unbound and is updated manually when a
change occurs in either the ComboBox or the DataGrid?
>
Other things to try. Bind the TextBox to the same BindingSource as the
ComboBox rather than updating it in the CurrentChanged event (although this
won't work if you use the same TextBox to display values from another
BindingSource as well). Try handling the ListChanged event, which should
fire if the underlying datasource changes. If the list is changed, get the
BindingSource.C urrent value and update the TextBox accordingly.
>
>
>
--
Happy Coding!
Morten Wennevik [C# MVP]
>
>
"Vanessa" wrote:
>

Hi All!

I am with a situation where I am not getting the right updating to the
form's fields. The situation is the following one:

I have one combobox and one textbox. I am using the CurrentChanged event of
the BindingSource of the combobox to update the textbox. When selecting an
item in the combobox or when selecting a row in the grid, it is updating the
textbox correctly. The problem is when I apply a filter in the grid, and then
the grid has no rows. I already made the following attempts:

- When there is no row in the grid, the event is not called, and textbox
mantains the previous content;
- If I call the CurrentChanged event directly when there is no rows in the
grid, in this case I clean up the textbox, but when I apply a filter again in
the grid and the position of the combobox does not modify (that is, it is in
the same register), the CurrentChanged is not called, and edit is blank
(because I cleaned before);
- I already tried to use “combo.Select edIndex = -1” but also did not worked.

Does someone has any idea of how can I solve this situation?

Thank you for any suggestion!
Vanessa