[RESOLVED] userControl questions

[Crash893]

I created a usercontrol to help elevate the flood of changes i need to make to a win form that has like 300 textboxes on it




I'm new to user controls so sorry if this is a little newbie ish

but i can create a control build the project and then put it on the main form

i can create a load event but how do i "address" the items of the control


for example my contorl has some combo boxes that i want to add items to

could it be usercontrol1.combobox1.items.add(); or something like that?

ive been playing around and googleing but i haven't found anything that i understand yet.


Thanks if you can point me to the right direction.

[warrenayen]

I need to understand - are the objects that this control is calling on the form?

If so, you'll need to do something like this

public void ChangeText(ref ComboBox cboBox)
{
cboBox.Items.Add("item to add");

}

call this by doing this:

this.mycontrol.ChangeText(ref this.ComboBoxtoChange);

[Crash893]

i'm not sure i understand the question


here is what i have: (sorry about the size)
Areas in blue are the different types of user control



before i started with the user control they were all individual items
and i had a loop that would add all the teamnames to each combobox

I also had a leave event and a text change event


how can i translate that over to the user control so that i can have a leave event for the combobox inside of the user control

and secondly

say you had a user control with two combo boxes
then you added 64 of thouse user controls to a form

how would you add items to the combo boxes?

[warrenayen]

I see, you're asking about making changes to the ComboBoxes that are INSIDE the User Controls, correct?

Then you do it pretty much the same way. You have to expose those ComboBoxes to the outside world, and the best way, in my opinion, is to write a custom method in the UserControl that allows you to add items to it. So for instance, you might call from your form a method on the control called "AddItemToList", and you'd pass the item you want to add.

Now since you so many of those different controls, I'd create my own class that has that method (to cut down on code), and extend the existing UserControl class and then have your controls inherit from it.

It's important to remember that all a User Control is is an extendable form (in a way). It simply allows you to group controls & functionality together that can be re-used multiple times.

[Crash893]

im starting to get the idea.

im still very weak when it comes to class's in general and inhertance is still just a vauge concept to me.

I am trying to push my knowlege on this one but at a certian point i might have to finish it useing methods that i know rather than not finish it on time with a more exotic (if not more elegant) solution


anyway


so what your saying is that i would write code under the usercontrol itself to accept incoming changes?

[Crash893]

here is what i have so far

(this is actually very cool)

under the user control

public void addtocombobox(string[] x)
{
CB_40_U.Items.Add(x);
CB_40_L.Items.Add(x);
}



then from the main form

string[] x = { "test", "test2" };
matchType11.addtocombobox(x);


and this i could loop

foreach matchtype1 in tabpage.controls

or something like that



then i assume that i would make my sub on the main form public and then hook that up to the textleave for text validation

Im really excited this will save me an S ton of work

[warrenayen]

It's very important to understand classes and inheritance, especially if you want to pursue a development career - you'll lose out on great opportunities.

Now, your control - yes, that is the best way to do it in this case, for the moment. Remember that controls on the UserControl are protected. They're not usually accessible from outside of the control, and you should not try to make them so. Methods are the best way of altering their information.

Onto inheritance. By extending the existing UserControl class, you can add custom code only once and have all of your controls use it.

This would be your code:

public class MyCustomControlClass : UserControl
    {
 
        //private variables
        protected string _myVariable = "";
 
        //my custom method
        public void MyCustomMethod(int myParameter1, int myParameter2)
        {
            //my custom code
 
        }
    }

See where it says : UserControl? The colon signifies that this class is inheriting all of the properties, fields, methods, functions, and events of the class specified, in this case, UserControl. This is important for large apps, for instance, if you have a special method you want to run on all of your forms, don't cut & paste to each one - instead, extend the existing Windows Form class and change the class your forms inherit from to that class instead. They'd then have access to all Form objects and yours, as well.

I suggest you research this topic and you'll find how much time it can save you!

[warrenayen]

Oh I also wanted to mention that you'll need to do this;

public void addtocombobox(string[] x)
{
CB_40_U.Items.Add(x[0]);
CB_40_L.Items.Add(x[1]);
}

Because you passed that as an array, you have to include the indexer

[Crash893]

well in this case no

becuase i want them to match

and it should be addrange i think

( im still working on it)