You might find yourself in a situation where you would like to clear all html controls in a form using a server command. Obviously, forms will either small or a large number of input controls like textbox, dropdownlist, checkbox and radiobutton, etc.
In the following "button click" example I will show you how to clear each control by first finding only “form” input controls, and then clear them to their default state(in my example they have to empty).
1: protected void Button1_Click(object sender, EventArgs e)
2: {
3: //Find controls in the web form
4: Control formCtrl = Page.FindControl("Form1");
5:
6: //For each control in the html form
7: foreach (Control ctrl in formCtrl.Controls)
8: {
9:
10: //Clears TextBox
11: if (ctrl is TextBox)
12: {
13: (ctrl as TextBox).Text = String.Empty;
14: }
15:
16: //Clears DropDown Selection
17: if (ctrl is DropDownList)
18: {
19: (ctrl as DropDownList).ClearSelection();
20: }
21:
22: //Clears ListBox Selection
23: if (ctrl is ListBox)
24: {
25: (ctrl as ListBox).ClearSelection();
26: }
27:
28: //Clears CheckBox Selection
29: if (ctrl is CheckBox)
30: {
31: (ctrl as CheckBox).Checked = false;
32: }
33:
34: //Clears RadioButton Selection
35: if (ctrl is RadioButtonList)
36: {
37: (ctrl as RadioButtonList).ClearSelection();
38: }
39:
40: //Clears CheckBox Selection
41: if (ctrl is CheckBoxList)
42: {
43: (ctrl as CheckBoxList).ClearSelection();
44: }
45: }
46:
47: }