VB.net User Control Issues - vb.net

I've created one user control which have textBox & DatabGridView etc. When any user start typing in textbox then the filter is applied in DatabGridView. Now I want to add following features in this control how can I add these?
I want to use same control for supplier, customer, vendors on a single form, so I've placed it 3 times from toolbar. But for each control I want to fill different data from database. So what will be the best way to bind the control?
As we knew each table (customer,supplier & vendor) can have different columns, so I also need properties to set them. I've added property to my control but how can I ensure user has assign value in it? I.e. if user run the form and X property is not assigned to control then it should show message.
Note: I've tried it on control load event but didn't get any success because control's load event is occurred prior to form load and I'm assigning property on form load.
Please help....

Related

restricting a combobox to list values and outdated list values

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.

How to create click event for dynamically created custom control?

Let say that I'm creating thousands of custom controls, each control has own data assigned to it (like name, id, etc.), now I would like to add
click event for each of these custom controls
access from software any of these dynamically created controls
So I would like to show MsgBox if user click control #452, which will be returning values assigned to object in custom control class (passed during creation of new control on user form)
Second thing is that I would like to access at any time any of these objects and read values assigned to object in control....
How to do it ? Each control has name assigned like "Example1", "Example2", "Example3" but I don't know how to access it from code as any of these exists during writing...
Also I were trying to find how to create and rise events but it seems that all solutions are for statically created controls and I need to rise events for dynamically crated custom controls....
Thanks in advance for any tips/help how to solve it.
I'm using VB.NET
Ok I figured it out !
It is very simple actually.
If any one will be looking for an answer :
To access dynamically created control first we are going to name it :
Dim Control as new CustomControl
Control.Name = "Name" & Counter
Next after we've created new controls we are going to access it using:
Dim _Control as new CustomControl
_Control = Ctype(Me.Panel1.Controls("Name1"), CustomControl)
MsgBox(_Control.Name.ToString)
Viola
I still not sure about custom events for all controls on custom control (so where ever user click, there should be override event which returns something back, now I can only either click panel container (not labels/pictureboxes) from code inside user class, or event per control on custom control (but issue is that I want to pass data from custom control to user class).

Visual Basic 2010 - Referencing objects in different user controls

For an app that uses user controls instead of forms and the first user control has a listview, where the user clicks or selects "Create New" Or Delete, what is the best way to transfer the data selected in the listview to the detail screen (separate User Control) where the data can be edited?
Can I just reference the list view in the first UC in the Details UC? something like:
ucHeader.lvSetups.FocusedItem.SubItems.Count = 0
from the ucDetail user control?
Saying which way is the best would produce a heated discussion with every ones opinion. However, here are a few ways I would tackle this. While there are more options, these are what I would do:
You should expose any information you want to read from a user control in the form of a property, readonly if you must. Just an example because I don't know what your object types are:
Public ReadOnly Property SelectedItem as object
get
Return Listview1.SelectedValue
end get
End Property
You can also use events to tell the parent of your user control that a selection was made. You can pass whatever you want in this event, even the selected object. If you don't want to pass the selected object, grab it from the property you created (like #1) in the event handler.

Need To Revert Multiple Controls Back To Previous Values

I have the following situation where I have multiple controls on a form. The user can select an Edit mode which allows them to modify the contents of the controls (textboxes, checkboxes, comboboxes, etc.) After editing has been made, the user can either select the Save or Cancel button.
Obviously clicking on save will save all changes to the database, however, if the user clicks on cancel, I want to 'somehow' revert all controls back to their previous state.
Currently, when the user clicks on cancel, the form turns off edit mode, but the controls remain with all the changes made until they reload the form.
Is there an easy way around this, or do I need to reload the entire form content from the database each time the user clicks on cancel?
Thanks in advance.
I'm just going to outline a possible solution here.
You could have a dictionary in your form in which you store the content of your controls whenever a user first modifies them, indexing them by the control name.
When the user starts modifying a control, you check if the control already exists in the dictionary. If it doesn't you add a new entry to the dictionary with the current value of teh control.
If the user cancels the editing process, you can loop through the dictionary, find each control in your form by its name (Form.Controls(ControlName) or something like that I think), set its value back to what it was and remove the entry from the dictionary.
It's not the most elegant solution as it will involve linking up all your controls to the TextChanged event or equivalent to capture their value when they are modified...
To avoid that, you could fill the dictionary right at the start when you load your form, after populating the values from the DB and then only set those controls' value back which have a different value when the user cancels.

VB.NET/Visual Studio 2010, incrementing control names at runtime

I am coding an invoicing application. The user should be able to add a new line to the billing section of the invoice by selecting a product from a ComboBox, which subsequently fills out various other fields (price, description, etc) based on the selected product.
My problem is this: When the user adds a product, I would like the program to automatically generate a new line for the next product. It seems like the only way to accomplish this would be to create a new set of controls with an incremented name, i.e. Product1, Price1, Desc1 for the first product, Product2, Price2, Desc2 for the second product, etc. Is this possible, or am I going about it all wrong?
I had to do something like this at one point and what I did was create a custome user control, in your case it would consist of a combo box, that is filled with products on load, and all the related controls, which would be filled out on the selectedindexchanged event of the combo box. On your main form where you want to display this info place a panel and add your custom user control to the panels.controls collection.
since all the functionality will basically be contained in the usercontrol itself you shouldn't run into naming issues.
As for adding the user control when the user makes a selection, you could dim the control withevents and attach a custom event to the user control and handle it in the main form. since the controls would be added at run time you would need to attach the event handlers using the AddHandler call.
So to break it down you would need:
A Custom user control with all the controls you want for each product and an ID in the code behind
An event on your custom user control to tell the main form that the combo box has a selected value
A panel on your main form to hold the custom user controls
An event handler to add a new customer user control to the panel when a selection is made in the combo box.
if you want to interact with a certain product with the same button you can attach an ID in the code behind of the user control and set that everytime a new user control is added. this is not as hard it I think I make it sound, you can actually run linq on the panels control collection and get all the panels where any condition you designate is met and then do what you want from there.
As for your second question, I would assume your user control is pulling a bogus connection string from somewhere. I would try to track down where that is happening and go from there. Anything beyond that would just be a WAG and that doesn't really help you.