[RESOLVED] accessing controls in a loop

Hi,
I have 6 pictureboxes on my form to display random pictures in.

I use several functions to load pictures, clear pictures etc. All of these functions have all 6 pictureboxes hardcoded.

For example:

Code:

---

private void ShowPics()
{
  this.pictureBox1.Image = this.pictures[this.rnd.Next(0, this.pictures.Length)];
  this.pictureBox2.Image = this.pictures[this.rnd.Next(0, this.pictures.Length)];
  this.pictureBox3.Image = this.pictures[this.rnd.Next(0, this.pictures.Length)];
  this.pictureBox4.Image = this.pictures[this.rnd.Next(0, this.pictures.Length)];
  this.pictureBox5.Image = this.pictures[this.rnd.Next(0, this.pictures.Length)];
  this.pictureBox6.Image = this.pictures[this.rnd.Next(0, this.pictures.Length)];
}

---

So if I wanted to add more pictureboxes I'd have to add lines to all those functions (for pictureBox6, 7, ...). Is there a more dynamic way to access each picturebox in a loop or arrayList or something?

How about an For i = 0 To 5 loop?

hi look at this example:

Code:

---

foreach (Control ctrl in this.Controls)
            {
                if (ctrl is PictureBox)
                {
                    MessageBox.Show(ctrl.Name);
                }
           
            }

---

this will display al the picturebox names in your form.so like this u can loop through your contols in your page

Hack,
How would you use the for loop with separate controls?

karthikeyan,
This works for .Name but not for .Image of the picturebox

That's because it's still being seen as an object. Try something more like this:

csharp Code:

foreach (Control ctrl in this.Controls)
{
   if (ctrl is PictureBox)
   {
      PictureBox pb = (PictureBox)ctrl; //cast it as a PictureBox to expose the right properties
      MessageBox.Show(pb.Image);
   }
}

Casting worked. Thanks.

I was hoping that I wouldn't have to go through all controls to find the boxes. I wonder how efficient would it be with lots of controls on the form.

No problem. Casting is an essential in C#. Probably the majority of type operations will involve some form of cast, otherwise C# won't know what type of object it's dealing with. Rather, it'll be dealing with the object type itself, and not the type you want it to.

If you want to loop through a number of controls then create an array of controls in code:

Code:

---

private PictureBox[] pictureBoxes;

public Form1()
{
    InitializeComponent();

    this.pictureBoxes = new PictureBox[] { this.pictureBox1,
                                          this.pictureBox2,
                                          this.pictureBox3 };
}

---