newbie: forms databinding question

[Dan]

I have a c# windows application binding some controls to a source table: I
can browse the table records by retrieving the CurrencyManager from the
form's BindingContext for my dataset and table and using the Position
property; but I'd like the form to show on demand A SPECIFIC RECORD (if
existing): i.e. I'd like to find a specific record as with the
DataTable.Select method, and set it as the CURRENT record for my form if
found. How can I do this? I don't think I can use Select as it rets a set of
rows but not their index in the table... and I'd need an index to set
CurrencyManager Position.

Thx to all guys!

 

[Sunder Thondamuthur]

Hi Dan
You can put a check Condition like if userenteredValue < TableRowsCount
then GO ahead and Show that row by setting the Position .
Code may look like this (Products is a Table)
Me.BindingContext(Dataset11, "Products").Position = UserEnteredValue

Alternatively you can get the Row from the Dataset
Like this for a Typed Dataset where Categories is a Table
Dataset11.Categories(UserEnteredValue ).CategoryName


Thanks
Sunder
VB.net

 

[Dan]

Thanks, anyway if I understand well these are ways of setting the position
to a specified index; my question was, how can I retrieve that index when
I'm searching for a specified value in a set of rows? E.g. let's say I have
a dataset with a table with some contacts, I want to find the index for the
contact named "Donald Duck" and then set this record (if found) as the
current row for my bound controls...

 

[Sunder Thondamuthur]

Hi Dan
Unfortunately there is no Direct Support to Get the Row Index of a Row as
DatarowCollection doesnt implement IList. To get the Row Index
you should Iterate thru all Records of a Dataset to get the Row Index
Sample Code may Look Like this

Dim index As Integer
For index = 0 To DataSet11.Categories.Rows.Count - 1
If DataSet11.Categories(index).CategoryID = "Your Value" Then
Return index
End If
Next

This will Defintely Hit Performance .

Alternative you can have a Parameterized Query Which will Take ContactName
and Fill the Dataset
.So your dataadapter Query may look like
Select * from Names where ContactName = @ContactName

You can Pass in the Contact Name at run time and Fill the Dataset . This
will be Fast and Efficient

There are some Examples on MSDN to Use Parameterized Query
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dndotnet/ht
ml/databindingadonet.asp

Thanks
Sunder
Vb.Net
--------------------

 

[Greg]

What about GetOrdinal?

Hi Dan
Unfortunately there is no Direct Support to Get the Row Index of a Row as
DatarowCollection doesnt implement IList. To get the Row Index
you should Iterate thru all Records of a Dataset to get the Row Index
Sample Code may Look Like this

Dim index As Integer
For index = 0 To DataSet11.Categories.Rows.Count - 1
If DataSet11.Categories(index).CategoryID = "Your Value" Then
Return index
End If
Next

This will Defintely Hit Performance .

Alternative you can have a Parameterized Query Which will Take ContactName
and Fill the Dataset
So your dataadapter Query may look like
Select * from Names where ContactName = @ContactName

You can Pass in the Contact Name at run time and Fill the Dataset . This
will be Fast and Efficient

There are some Examples on MSDN to Use Parameterized Query
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dndotnet/ht