I made a windows form which contains a listbox (named VenueList). The listbox is pulling it's values from a list provided by a binding source VenuesBindingSource which is pulling in a ID for the value and a name for the text.
There is a button which is causing a DialogBox to appear which is asking for values to store in the database for a NEW venue. Once the values are filled and insert the database, what's supposed to happen is that the dialog box closes and goes back to the original form which invoked it.
However, instead of updating the list. The list stays the same. But if you close the form and reopen it, you see that a new value was added.
TournamentSettings.VenuesTableAdapter.InsertVenueQuery(Trim(VenueNameTxt.Text), Trim(VenueAddress1Txt.Text), Trim(VenueAddress2Txt.Text), Trim(VenueCityTxt.Text), Trim(VenueProvinceTxt.Text), Trim(VenueZipTxt.Text), Trim(CountryBox.SelectedValue), Trim(VenuePhoneNo.Text), VenueType.SelectedText, VenueWebAddress)
TournamentSettings.VenuesTableAdapter.Fill(TournamentSettings.VenueNameList.Venues)
In the above code, InsertVenueQuery is the name of a query from the designer which is invoked to add the values onto the tableadapter VenuesTableAdapter which is used to fill the combo box on load. I also sent the Fill command to refill the table with the new value.
So the question is, should I go about doing this another way, rather than feeding the Table adapter and sending a fill command on to the datatable? Or is there something that I'm not doing here which I should to force that value into the list. I'm tempted to redo everything outside of the designer but that's a lot of code since I have to essentially run two commands (one to insert the data, and another to get the ##IDENTITY value since this is run on an access database.)
Okay. This one I had to think about for a moment.
Instead of me creating a block of done on the load event, I instead created a sub function called "FillVenueList".
I used the following block of code:
Public Sub FillVenueList()
' Adding values from database to a datatable.
' From there will add to the list box.
Dim VenueConnection As New OleDb.OleDbConnection(DBconnection)
VenueConnection.Open()
Dim VenueConnectionQuery As New OleDb.OleDbCommand("SELECT VenueID, VenueName FROM Venues", VenueConnection)
Dim VenueDataAdapter As New OleDb.OleDbDataAdapter(VenueConnectionQuery)
Dim VenueDataSet As New DataSet
VenueDataAdapter.Fill(VenueDataSet, "Venues")
TrnVenueLst.DataSource = VenueDataSet.Tables("Venues")
TrnVenueLst.DisplayMember = "VenueName"
TrnVenueLst.ValueMember = "VenueID"
VenueConnection.Close()
End Sub
From there I called THIS sub on both the form AND the Add Venue window and I can safely see that this works. SO THAT is how you get a new value onto the form, don't use it as a part of the Load Event but rather call it from the load event block, then call it when you want to add to the list.
Related
I'm trying to optimize the performance of my access frontend. One of the problems I'm stumbling on is how to set a multi-window form to open immediately to a specific record, because at the moment it queries everything twice.
Essentially, I allow my users to open multiple instances of a form. That way, a user can compare multiple records by placing the windows of those forms side by side.
At the moment, my code looks like this:
Set frm = New Form_Name
frm.RecordSource = "select * from Table where id = " & ID 'ID is a variable passed to the method
I'm pretty sure back then this question was one of the building blocks I relied on.
The problem is that on the first line, access already entirely opens the form and does everything the form does when opening, such as Form_Open, Form_Current, and loading subforms. Then, when I set the recordsource, it does all (or most) of that again, which significantly slows down the process of opening the form.
Here are some of the things I've tried:
Changing the Form_Current to recognize that it's being "used" twice and only actually run the code once. The problem is that the code is already very optimized and doesn't seem to be the bottleneck, so this doesn't seem to do much. Actually opening the form seems to be the bottleneck.
Trying to change the properties of the original form so that it opens the specific record I need, but I can't seem to change the properties without it opening the form.
Looking for a way to supply arguments to the form. That doesn't seem to be supported in VBA.
One other idea that popped into my mind was creating a variable in vba with the ID of the record, setting recordsource in the form properties to fetch that variable, but then, when I would open another form and change that ID, the form
I realize that I can do this with DoCmd.OpenForm, but that doesn't give me the option to open multiple instances of the same form.
How can I achieve this? This would mean a significant performance improvement.
OK, so I actually wanted to ask this question. But just before I hit the submit button, I had an idea...
Here's the idea: you set a global variable in VBA, which you then access in the form filter command. In my case I just added Public OpeningID As Long at the top of my VBA module. Then I create a function to get that value:
Public Function getFormID() As Long
getFormID = OpeningID
End Function
Then, in the form, you can set the filter criteria as ID = getFormID(). And then when you open the form instance, you do it like this:
OpeningID = ID
Set frm = New Form_Name
OpenindID = 0 'reset this to make sure that if it's being accessed when it shouldn't, it generates a clear error
The only problem is what happens when you refresh the form, as that will call the method again. When you refresh the form via VBA, you can set the OpeningID beforehand, and to avoid users refreshing the form, you can add this to your form (don't forget to turn on Key Previews in the form settings):
Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
If KeyCode = vbKeyF5 Then KeyCode = 0
End Sub
Bang. Forms open almost twice as fast. Awesome.
Whenever a user selects a cell in a sheet I want a windows form to appear and any previous windows form that was connected to the previously active cell to be dissapear. How can I do this?
I'm thinking a solution like the following would work, but I don't know if it is good practice and I also don't know how to execute the command that I have commented out
Sub CreateNewFormForActiveCellAndDeleteThePreviousOne()
'Remove all previous instances of class Frm
Dim Frm as New Frm
End Sub
Instead of creating a new form instance I'd suggest updating the data on the form instead. Thus, you will save resources required for creating a new form instance. For example, you may define a public field in the Form's class and update it according to the selected cell in Excel.
I have a page in my web application that contains two listboxes with buttons to move items back & forth between them. Each listbox is bound to a SQL query, the results of which change as the selected items are added or removed from the corresponding lists. This all works fine, except I cannot get the list boxes to update their contents on the fly, however if I refresh the web page, the contents update correctly.
Basically the user selects items in LeftListbox and clicks the Add button which calls code to loop through the LeftListbox and for each selected item adds a new record to a table (Score). The RightListbox should then update to show that the items have been added to the table.
Here is a snippet of code from the Click event of the Add button:
Dim i As Integer
For i = 0 To (LeftListbox.Items.Count() - 1)
If LeftListbox.Items(i).Selected Then
Try
DbUtils.StartTransaction()
Dim rec As ScoreRecord = New ScoreRecord
rec.Player_ID = CInt(Me.LeftListbox.Items(i).Value)
rec.Save()
DbUtils.CommitTransaction()
Catch ex As Exception
DbUtils.RollBackTransaction()
Me.Page.ErrorOnPage = True
Finally
DbUtils.EndTransaction()
End Try
End If
Next i
'** Here is where I want to refresh the list **
I've searched quite a bit for a solution, but I can't find anything that works so any help would be much appreciated.
Andrew
Use the same method (or code) used to populate the "right listbox" in the first place. The right ListBox's DataSource will be the same as it was prior to this code snipped being ran, so it must be updated since the underlying data has changed.
I have a vb.net 2010 form with 22 data bound controls from two tables held in a dataset which is navigated by a bindingnavigator. This successfully adds deletes and updates. However what I need is when adding a new record I need some of the fields to be pre filled out. More specifically I have points balance fields etc which could be any value but will normally be 0 on a new customer so I want to initialise them to 0 when adding new records.
I located an AddingNew event on my datasource but this is called before the new item is added and thus all my initialisation is lost.
any help on this would be appreciated.
kind regards
Feldoh
Since you are using DataTables, you can manually set the DefaultValue property of the DataColumn:
Dim dt As New DataTable
Dim dc As New DataColumn("test", GetType(String))
dc.DefaultValue = "hello"
dt.Columns.Add(dc)
dt.Rows.Add()
Debug.WriteLine(dt.Rows(0)("test").ToString)
Result: hello
Answer including multiple linked tables solution:
Like LarsTech said using
dataset.table.Columns.Item("someField").DefaultValue = someValue
works nicely if you have a standard default but it also works for generated defaults, if you reset this default on saving to the next value you want if a new addition is made. However if you are using a dataset as your data source where a child table record cannot feasibly be generated (like in my case where an account id will be generated only on saving using a database trigger to link all different kinds of accounts) you can still set defaults for the other fields, the ones from the sibling (or non-existent parent) table but
dataset.siblingTable.Columns.Item("someField").DefaultValue = someValue
WILL NOT WORK as the binding navigator only generates the first sibling and the parent is not generated until the trigger. However on the BindingSource.PositionChanged event of the binding source that IS generated by clicking add you can freely put defaults into the actual controls on the screen and they will not be overwritten by nulls, clearly you need to restrict this so it only happens if the user pressed add by adding a variable to the Clicked event of the add button to tell you when add has been clicked and resetting this variable on save or roll-back. It is also possible to modify the bindings themselves which have an if null or empty default value.
Hope this helps someone else :)
Use the MouseUp event on the 'Add Row' button in the BindingNavigator instead of the "Click" event. This is becouse the new ROW does not exist in the datagridview until AFTER the click event is completed.
Private Sub BindingNavigatorAddNewItem_MouseUp(sender As Object, e As MouseEventArgs) Handles BindingNavigatorAddNewItem.MouseUp
'works with add row from the binding navigator
myDataGridView.Item(3, myDataGridView.CurrentRow.Index).Value = txtDefaultDescrip.Text.Trim
End Sub
to do this same thing when adding data directly in you DataGridView do this.
Private Sub myDataGridView_DefaultValuesNeeded(sender As Object, e As DataGridViewRowEventArgs) Handles myDataGridView.DefaultValuesNeeded
'works with add row inside a datagridview
e.Row.Cells(3).Value = txtDefaultDescrip.Text.Trim
End Sub
In this example I have a editable default value shown on my from. If you have a non-changing default value (e.g., is always 1 for column 3) then you should do that when setting up your datasource.
I'm currently creating a WinForm in VB.NET bound to an access database.
Basically what i have are two forms: one is a search form used to search the database, and the other is a details form. You run a search on the searchForm and it returns a list of Primary Keys and a few other identifying values. You then double click on the entry you want to view, and it loads the details form.
The Details form has a collection of databound controls to display the data: mostly text boxes and checkboxs. The way i've set it up is i used the UI to build the form and then set the DataBindings Property of each control to "TblPropertiesBindingSource - " where value name is one of the values in the table (such as PropertyID or HasWoodFloor).
Then, when you double click an entry in the searchform, I handle the event by parsing the Primary Key (PropertyID) out of the selected row and then storing this to the details form:
Note: Detail is the details form that is opened to display the info
Private Sub propView_CellDoubleClick(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles propView.CellDoubleClick
Dim detail As frmPropertiesDetail = New frmPropertiesDetail
detail.id = propView.Rows(e.RowIndex).Cells(0).Value
detail.Show()
End Sub
Then, upon loading the details form, it set's the filter on the BindSource as such:
TblPropertiesBindingSource.Filter() = "PropertyID=" & id
This works great so far. All the controls on the details form will display the correct info. The problem is updating changes.
Scenario:
If i have the user load the details for say, property 10001, it will show a description in a textBox named descriptionBox which is identical to the value of the description value of for that entry in the database. I want the user to then be able to change the text of the text box (which they can currently do) and click the save button (saveBut) and have the form update all the values in the controls to the database.
Theorectically, it should do this as the controls are DataBound, thus i can avoid writing code that tells each entry in the database row to take the value of the aligned control.
I've tried calleding PropertiesTableAdapter.Update(PropertiesBindingSource.DataSource), but that doesnt seem to do it.
Ok, I was able to figure this out picking apart some code I pillaged from a friend.
Everything was ok, the problem was the updating
When I was saving the data, i was calling just:
Me.TblProptertiesTableAdapter.Update(Me.TblPropertiesBindingSource.DataSource)
The correct code, without changing anything else is:
Me.Validate()
Me.TblPropertiesBindingSource.EndEdit()
Me.TblPropertiesTableAdapter.Update(Me.RentalPropertiesDataSet.tblProperties)
Me.RentalPropertiesDataSet.AcceptChanges()
Where RentalPropertiesDataSet is the database where TblProperties comes from. Inorder for this to work, make sure TblPropertiesBindingSource.DataSource is RentalPropertiesDataSet.Properties This was autosetup for me by VS08 when it created the BindingSource.
Basically, I needed to tell teh BindingSource to stop allowing the fields to be edited. Then we save the changes to the database, and lastly we tell the DataBase to accept the changes.