Solved

C# WinForms - What order are controls added to control collection?

Posted on 2006-11-02
5
776 Views
Last Modified: 2008-02-01
I have a C# WinFroms Application with the following code:

for (int i = 0; i < this.Controls.Count; i++)
  {
    if (this.Controls[i] is ListBox)
      {
         Control newCtrl = this.Controls[i];
         ListBox lb = (ListBox)newCtrl;
         lb.ClearSelected();
       }
  }

When I step through the code, the controls do not seem to be in any particular order within the collection.  In order for my code to work correctly, I need to clear certain listboxes, before clearing other listboxes.  Is there a way to designate what order the controls are put into the collection?

Thanks,
Sarah
0
Comment
Question by:spendergrass
5 Comments
 
LVL 85

Expert Comment

by:Mike Tomlinson
ID: 17862839
If you know the names before hand, then do something more along these lines:
       
        private void button1_Click(object sender, EventArgs e)
        {
            ListBox lb;
            lb = (ListBox)getControlByName(this, "listBox1");
            lb.ClearSelected();
            lb = (ListBox)getControlByName(this, "listBox2");
            lb.ClearSelected();
            lb = (ListBox)getControlByName(this, "listBox3");
            lb.ClearSelected();
        }

        private Control getControlByName(Control ctl, string ctlName)
        {
            foreach (Control child in ctl.Controls)
            {
                if (child.Name == ctlName)
                    return child;
                else if (child.HasChildren)
                {
                    Control retChild = getControlByName(child, ctlName);
                    if (retChild != null)
                        return retChild;
                }
            }
            return null;
        }

You can of course do more error checking than I did.  Make sure that null was not returned and the the returned control was actually a ListBox before casting it...
0
 
LVL 12

Accepted Solution

by:
RubenvdLinden earned 500 total points
ID: 17862842
It's first come, first serve.

Please check the methods which adds the controls to your WinForm application (normally, this would be InitializeComponent()).
There will be several statements like: this.Controls.Add(this.yourControl).
As I said, it's first come, first serve. If you change the order of these statements, the placement in the collection will be different too.

I hope this will help you.
0
 
LVL 85

Expert Comment

by:Mike Tomlinson
ID: 17862846
But after seeing that...if you have a specific order and know the names, then why not just do it directly?

    listBox1.ClearSelected();
    listBox2.ClearSelected();
    listBox3.ClearSelected();
0
 
LVL 8

Expert Comment

by:sabeesh
ID: 17864078
Hi
       you can set "Tag" for your listbox and with respect the tag name you can clear or do whatever you want.
0
 

Author Comment

by:spendergrass
ID: 17866455
I was hoping to be able to keep the code that I posted generic - not having to specify the order within that section of code.  Changing the order the controls are added to the form will allow me to do this.  Thanks everyone for your help!

Sarah
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Calculating holidays and working days is a function that is often needed yet it is not one found within the Framework. This article presents one approach to building a working-day calculator for use in .NET.
Performance in games development is paramount: every microsecond counts to be able to do everything in less than 33ms (aiming at 16ms). C# foreach statement is one of the worst performance killers, and here I explain why.
How to Install VMware Tools in Red Hat Enterprise Linux 6.4 (RHEL 6.4) Step-by-Step Tutorial
Are you ready to implement Active Directory best practices without reading 300+ pages? You're in luck. In this webinar hosted by Skyport Systems, you gain insight into Microsoft's latest comprehensive guide, with tips on the best and easiest way…

756 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question