VB 2008 .NET 3.5
I have a custom "Shipment" object that contains a list of "ShippingRate" objects. This list of "ShippingRates" is accessible through a property "Shipment.PossibleShippingRates." That property simply returns a copy of the list of "ShippingRate" for that particular Shipment.
My UI layer receives a list of "Shipment" objects from the BLL. This list is databound to a datagridview, and shows details relevant to the Shipment such as Shipping Address, etc.
I want to bind the "Shipment.PossibleShippingRates" property to a combobox, such that when the user changes the grid row, the combobox reflects the "PossibleShippingRates" for that "Shipment."
In addition, I need a way to store the "ShippingRate" they selected from the combobox for later use.
I have tried a few ideas, but none of them work properly. Any ideas on how to do this?
Wouldn't the simplest solution be to tie a TextChanged or SelectedIndexChanged event to any/all fields in the datagrid that need to trigger a refresh of the combobox?
Related
I am creating a program that for simplicity's sake records the name of a staff member that receives a phone call. This program is designed to show old entries along with creating new ones.
The problem is that I want a user to only be able to select a listed name from the drop box when creating a new entry. But this list will only show current employees. Yet, when viewing older calls this combobox field also needs to display former employees that took a call that may no longer be in this list.
As far as I can tell with the Microsoft control and properties there is only 2 options that relate to this matter.
DropDownStyle as DropDown or DropDownList.
When using DropDown the user can submit any name (which is not wanted).
With DropDownList the user can only submit names on the list, but when browsing through old entries any names that are no longer on that list will not appear on their respective calls (which is also not wanted).
I'm aware I could end up having to implement my own combobox class but I wanted to see if anyone knew of a more elegant fix that combined both of these functionalities. Thanks!
It seems to me you have two modes. Add mode adds a new call record, while view mode displays old records.
Use the drop down list to restrict the user to what you load. When in Add mode, load the control with only current employees. When the form is in view mode, load with all employees.
Use DropDown. In the Validating event, set e.Cancel = True and instruct an ErrorProvider control to put up a warning with its SetError method if SelectedItem Is Nothing, but clear the error (by passing Nothing to SetError) otherwise. Then, in the combo box's SelectionChangeCommitted event, call the form's Validate method.
I need to create combobox containing items with checkbox. This is winform VB.NET application.
I found some options but, those are in c# and also, in separate library.
I need some simple way like some single class which allow me to create item with checkbox and iterate checked items.
can any one suggest me way ?
Thank You
I want to be able to reorder my listbox which is bound to my sql ce database by clicking up and down arrow buttons. Since my listbox is populated directly from my database using the entity framework, I think I have to delete the object (from the listbox) and reinsert it (in the row above) if I want to move the item up the list.
I have no view model, my listbox is populated directly from my database in my code like this:
listBoxProperties.ItemsSource = entities.Properties.ToList();
Does my question make sense?
Cheers
ormally you would handle the moving of your list item in your view model which would hold the ObservableCollection the control was bound to - and then that would be reflected in your control via the binding.
It is going to get messy trying to accomplish this dirrectly on the control - which is your only way since your binding to a throwaway copy of the EF properties list.
As your UI dev goes on you are only going to run into more issues like this. I strongly recommend getting a view model in place sooner rather that later.
I have a search screen within my application that has a ComboBox which is bound to an ObservableCollection in a ViewModel (the collection contains Organisation entities returned via WCF from an Entity Framework model).
I wish to add an item to the combo representing "All Organisations" - so the user does not have to specify an organisation when searching.
Is there a way of adding custom items to a ComboBox or do I have to add a dummy Organisation to the collection and carry out the necessary logic when this is selected.
Have a look at WPF combo box, adding an all options item, when binding to an Observable Collection. It describes one option which is a CompositeCollection.
I have a List of an object, set to DataSource of a BindingSource, set to DataSource of a DataGridView. Then I added a DataGridViewButtonColumn which I want a click to remove that record from the collection. So I simply call collection.RemoveAt(e.rowIndex) from the DataGridView CellClick event. However this produces an IndexOutOfRange Exception; "1 does not have a value"..
So is happening here? I have maybe a vague idea, but would like to understand exactly which events are failing etc.. and what do i need to do to perform this action properly?
EDIT:
This seems not to happen if I use a BindingList.. But when using a List, I get this problem..
The reason you're seeing the error is because you're ultimately binding to a List. List doesn't include the notifications of changes that your DataGridView needs to receive to reflect the changes you make.
If you really want to work around this you could do the following: just before you make a changes to your List, set the BindingSource's DataSource property to Nothing. When you're done making changes reset your List to the DataSource.
This is a pretty ugly solution as you can imagine. What you'll want to do this bind to an object that implements IBindingList, either a custom collection you create or a BindingList.
Here's a reasonable starting point for investigating this further:
DataGridView Control Overview (Windows Forms)