When a user changes the selected item on a dropdown I need to get the PREVIOUS item selected,
EX:
dropdown items:
1) Questions
2) Jobs
3) Tags
4) Badges
User has #2 Selected and then changes to #4 -- How can I get the value of #2 when they change the selection?
Declare an instance variable in your form (WinForms) or window (WPF).
When a user selects an item:
Do what you want to do.
Save the current item index in the instance variable.
In step 1, you can now access the instance variable to get the previously selected item.
Declare a global variable that will contain the previous value.
When the user changes the selection in the combobox, set the variable to the currently selected value. Allow the selection to be changed. You now will have the previous value.
If you need to have the history of changes, then the global variable would be a collection. Then on changed event, add the current selection to the collection.
If your control is bound to data, there is no need to "Squirrel" the old value away, your data provider usually does this for you.
For example, if you are bound to a DataRow, this code will get the previous value.
? = [Your DataRow].item("[Your column name]",OrigialVersion)
This varies based on your data but ultimately, you could always re-query the database to get the original value as well.
Regardless of what you are bound too, if you ask the datasource for it's value during the Validating event of the control, it will have not changed yet so it will give you the old value, which you can then compare against the current selection.
Lastly, if you are not bound to data, I typically store the old value in the TAG property on the GotFocus event of the control. Then you can compare against that.
Hope this provides some other options that might help you, depending on your case.
Related
I have an MS ACCESS Combo Box and I wish to change the value of one of the columns in a particular row. I get error "object required" when I run this line:
Me.ComboName.Column(12, intUseRow) = myVar
(If I am unable to use the above syntax then you should also know that the row I am trying to change is always going to be the "current" visible row so there may be another way of solving the problem due to this fact).
Thanks!
If you have a recordset that is bound to a Table/Query, you will need to change the underlying data then requery the combobox to see changes.
If you load it manually (like in the form load event) and have the comboBox Row Source Type to "Value List" - you should be able to update it like this:
Copy all the data from the selected row into variables.
Combobox.RemoveItem (selected index)
change the required variable to the new value.
construct the semicolon separated string for the value list entry
combobox.AddItem new-string.
a bit messy, but it works correctly!
is it possible to create listbox with multiple checkboxes in one row (Excel VBA)?
Thanks
Kamil
I'm not sure I understood your question fully, but I'll elaborate on ListBoxes as much as I can.
First things first: Checkboxes and ListBoxes are different objects in Excel Userforms. The first is the little box that returns a "true/false". The second is a list of items which can be chosen. Clicking in a Checkbox will make the tick mark appear/disappear (or fade if tristate is enabled), while clicking a Listbox row will turn the listbox row "blue"/"white" (or whatever color is being used for the selected rows). In both elements, clicking is a way to toggle between True and False.
While a checkbox only allows for a single information to be marked as True or False, a Listbox allows you to select entries out of a list. That list may be inserted through code (.AddItem method) or passed from a range (.RowSource property)
ListBox objects allow for multiple columns of data to be attributed to one row element, but each row is an entire element (which means you cannot pick the element on row 3, column 2 - only all of row 3). The number of columns is established using the ColumnCount property.
By changing the value of the MultiSelect property, you'll allow the user to select multiple or single row elements simultaneously on your Listbox. Using the Selected( RowIndex ) property, you can check whether or not an item is currently selected (returns True/False). Remember that row indexes start at 0.
Finally, if you're using the MultiSelect property set to fmMultiSelectSingle and have a single column (as far as I know), the Text property can be used to return the selected item's value.
An easy example of a listbox is in Excel can be found at File > Options > Customize Ribbon (or something like that). There are two listboxes, one (on the left) with the visible items and another with the available items. A pair of command buttons is used to move items between boxes. That's a simple application you can likely find already setup online.
Am I on track to answer your question?
I have an update statement under RowLeave event of my datagridview. Before I update it I need to validate the cell if there is an empty value. But whenever I moved the focus to another row, RowLeave is called first before CellLeave/CellValidating.
Is there another way of validating the cell when leaving a row?
Note: Leaving a cell in the same row is not a problem.
Well your app is acting as designed, see if you can listen to something in the nature of cellexitEditmode or cell validated (not entirely sure these are all there). Best practice is if the row represents and object that is bound say your row represents an order and your grid is bound to a collection of orders . the cell will be a property in an order you can validate on property changed.
I'm using an Infragistics UltraWinGrid with a column of drop-down boxes. I don't want the user to be able to select the same value for multiple rows in that column. Is there a simple (or heck, I'd settle for advanced) way to do this?
I'm using VB.NET
-EDIT-
I tried setting a filter on the data source for the drop-down box. But when I did that, the values in the other boxes in that column started disappearing (not the values themselves, but the descriptions that they were supposed to represent, so instead of reading "Information", it just said "1"). All of the cells in a column refer to the same combo box, so if you filter out a value from the data source for one of them, you filter it out for all of them.
I'm currently trying to catch a CellChange event and check against all other currently-used values. If it was already used, I would put up a message saying as much and revert back to the old value. However, the value comes back as the previously-saved one, so... not helpful. About to see if I can use the "text" property.
Since you're using Infragistics, you could use an UltraDropDown which is bound to a DataTable (or something similiar) which you can add a "Selected" column in addition to a column holding the values you want to show.
As each value is selected (via AfterCellUpdate or AfterCellListCloseUp for instance), you could update the "Selected" column in that data source and use a column filter to only show items which haven't been marked as selected. That way as items are selected or removed, the contents of the drop-down would be automatically updated.
To clear the selected flag from the old value, you can use the BeforeCellUpdate event to access the cell's current value then perform a lookup on the data source bound to the UltraDropDown using that value to clear the flag.
Solved it:
The trick was to use BeforeCellUpdate whose BeforeCellUpdateEventArgs has a "NewValue" and a "Cancel" member. I just look through all of the items in the column to see if any of them match the new value. If one does, I notify the user and cancel the operation.
And that's it. Here's the code:
Private Sub myUltraWinGrid_BeforeCellUpdate(ByVal sender As Object, ByVal e As Infragistics.Win.UltraWinGrid.BeforeCellUpdateEventArgs) Handles myUltraWinGrid.BeforeCellUpdate
If e.Cell.Column.Key = "myColumn" Then
Dim newValue As Integer = CInt(e.NewValue)
For Each row As Infragistics.Win.UltraWinGrid.UltraGridRow In myUltraWinGrid.Rows
If row.Cells("myColumn") IsNot e.Cell _ 'So I'm not checking against the current cell
AndAlso CInt(row.Cells("myColumn").Value) = newValue Then
MsgBox("That value has already been used in this column")
e.Cancel = True
End If
Next
End If
End Sub
I have a standard form in MS-Access which lists a bunch of orders, and each row contains order no, customer, etc fields + a button to view notes and attached document files.
On request from our customer we should gray out the button btnAnm (or check or uncheck a checkbox) depending on a calculation from two queries to two other tables (a SELECT COUNT WHERE and a check if a text field is empty).
I've tried btnAnm_BeforeUpdate(...) and btnAnm_BeforeRender(...) and put breakpoints in the subs, but none of them trigger. The same if I use the control Ordernr instead of btnAnm.
I'd like a function in the Detail VBA code to be triggered for each "Me." (row) so to speak, and set the row's control's properties in that sub.
What do I do? I've looked at the help file and searched here.
*Edit: So I want to do something that "isn't made to work that way"? Ie. events are not triggered in Details.
As an alternative, could I base the value of a checkbox on each line on a query based on the 'Ordernr' field of the current row and the result of a SELECT COUNT from another table and empty field check?
Do I do this in the query the list is based on, or can I bind the extra checkbox field to a query?
A description of how to do this (combine a COUNT and a WHERE "not empty" to yes/no checkbox value) would be perfectly acceptable, I think! :)*
You cannot do much with an unbound control in a continuous form, anything you do will only apply to the current record. You can use a bound control with a click event so that it acts like a button.
Presumably the related documents have a reference to the order number that appears on your form, which means that you can create a control, let us call it CountOrders, with a ControlSource like so:
=DCount("OrderID","QueryName","OrderID=" & [OrderID])
The control can be hidden, or you can set it up to return true or False for use with a textbox, you can also use it for Conditional Formatting, but sadly, not for command buttons.
Expression Is [CountOrders]>0
You can also hide the contents and add a click event so that is acts in place of the command button. Conditional Formatting will allow you to enable or disable a textbox.
As I understand your question, you have a continuous form with as command button that appears on each row - and you'd like to enable/disable the button conditionally depending on the contents of the row.
Unfortunately you can't do that. It seems that you can't reference the individual command buttons separately.
Having wanted to do something similar in the past I came up with two alternate ways of setting up my interface.
Put a trap into the onClick code for the Button. Which is icky, because it is counter intuitive to the user. But it gets you that functionality now.
Move the command button (and editable fields) up into the form header, and make the rows read only. Your users then interact with the record only in the header, and select the record they want work with in the list below. As I recall this is known a Master-Detail interface.