Question

i can iterate through the controls which are on panel by this two code

       Form4 fl = new Form4();
       StringBuilder sb = new StringBuilder();
       foreach (Control c in panel1.Controls)
       {
           if (c is ComboBox)
           {
               ComboBox cb = (ComboBox)c;
               sb.Append(cb.Text);
               fl.comboBox1.Text = sb.ToString();
               fl.Show();
           }

       } 

OR by this
List lst = new List();
void GetComboBoxValues()

    StringBuilder sb = new StringBuilder();
    {
      sb.Append(c.Text + "\r\n");
    }
   MessageBox.Show(sb.ToString());
     }

but i add a panel and on panel a usercontrol which contains a combobox and textbox how that can be possible to find controls and add to the string builder
so i thought iterating through usercontrol and finding the text and adding it to the string builder,is that possible?

Answer 1

Responding to the comment left for L.B’s answer. Personally I believe L.B’s answer is the easiest and requires the least amount of coding, the best thing is it will find all the controls of a specific type on a panel no matter how nested they are(imagine if you have a user control inside a user control).

Just copy the FindControls method from LB’s answer to your solution as is and where you need to loop through the controls of the panel, do something like this:

StringBuilder sb = new StringBuilder();
var comboBoxes = FindControls<ComboBox>(panel1).ToList();
var textBoxes = FindControls<TextBox>(panel1).ToList();

foreach (var comboBox in comboBoxes)
    sb.AppendLine(comboBox.SelectedItem.ToString());

foreach (var textbox in textBoxes)
    sb.AppendLine(textbox.Text);

MessageBox.Show(sb.ToString());

A simple example would be something like this, but be warned that it will not work if you have a case of a user control inside a user control, so I would strongly suggest going with LB’s example:

    StringBuilder sb = new StringBuilder();
    for (int i = 0; i < panel1.Controls.Count; i++)
    {
        if (panel1.Controls[i].Controls.Count > 0)
        {
            //Iterate through the controls in the user control
            foreach(Control c in panel1.Controls[i].Controls)
            {
            }
        }
        else
        {
            //Handle the controls with no children
        }
    }