CODEWITHSUNDEEP
c#eventsgroupbox
phadaphunk
phadaphunk

Reputation: 13313

Groupbox check for changes event

I have a DataGridView and a GroupBox control containing a few ComboBoxes.
Depending on what is selected in the ComboBoxes, the elements in the grid changes.

Is there a way to say 

If (Something Changes Within The GroupBox)
{
   //Update the grid
}

(Without writing a OnSelectedIndexChange event for every boxes)
I don't want the code for the updating part, I just need an event or something I could use to check if a the value of a control has changed within the GroupBox.
Any Idea ?

Update

Ok I think I didn't explained it the right way.
Forget about the ComboBox.
Let's say I have a bunch of controls in a GroupBox is there a way to say :

As soon as the value of one of the control changes, create an event.

Upvotes: 2

Views: 9984

Answers (3)

Dave New
Dave New

Reputation: 40092

You could hook up each combo box SelectedIndexChanged event to one method:

comboBox1.SelectedIndexChanged += new System.EventHandler(GroupBoxComboBoxChange);
comboBox2.SelectedIndexChanged += new System.EventHandler(GroupBoxComboBoxChange);
comboBox3.SelectedIndexChanged += new System.EventHandler(GroupBoxComboBoxChange);
comboBox4.SelectedIndexChanged += new System.EventHandler(GroupBoxComboBoxChange);

Or using LINQ to setup an event handler for any combo box selection change:

GroupBox.Controls.OfType<ComboBox>.ForEach(cb => cb.SelectedIndexChanged += new System.EventHandler(GroupBoxComboBoxChange));

Answer to your update: You are looking for a ControlValueChanged() event. I think the problem here is that all controls are different. What defines a "ValueChanged" event for a ComboBox isn't necessarily the same for a TextBox. It would be a semantic challenge and not very clear. Hope this makes sense.

Upvotes: 9

Alex
Alex

Reputation: 23310

There is no "something inside me changed" for GroupBoxes, but you can "cheat" and DYI like this (it's just a proof-of-concept without error checking and the sort):

// In a new Windows Forms Application, drop a GroupBox with a ComboBox and a CheckBox inside
// Then drop a TextBox outside the ComboBox. Then copy-paste.

// this goes somewhere in your project
public static class handlerClass
{
    public static string ControlChanged(Control whatChanged)
    {
        return whatChanged.Name;
    }
}

// And then you go like this in the Load event of the GroupBox container
void Form1_Load(object sender, EventArgs args)
{
    foreach (Control c in groupBox1.Controls)
    {
        if (c is ComboBox) 
            (c as ComboBox).SelectedValueChanged += (s, e) => { textBox1.Text = handlerClass.Handle(c); }; 
        if (c is CheckBox) 
            (c as CheckBox).CheckedChanged += (s, e) => { textBox1.Text = handlerClass.Handle(c); }; }
    }
}

Since every Control has its own "I'm changed!" kind of event, I don't think it can be any shorter as far as boilerplate goes. Behavior is a mere sample that writes the name of the control that changed in a ComboBox

Upvotes: 3

GrayFox374
GrayFox374

Reputation: 1782

GroupBoxes are usually just decorative unless they are managing radio buttons or check boxes, so expecting them to be aware of changes made to combo boxes is not something easily done out of the box. If I may, why not code a method that does what you want it to do, and then call that method from all your combo boxes' SelectedIndexChanged events?

Upvotes: 2

Related Questions