How to clear all form fields from code-behind?

Question

HTML has an input button type to reset all fields in a form to their initial state in one step: <input type="reset" ... />.

Is there a similar simple way to reset all form fields of an aspx page from code-behind? Or is it necessary to reset all controls one by one with TextBox1.Text=string.Empty, TextBox2.Text=string.Empty, etc. ?

Thanks in advance!

Update:

Context is a simple Contact/"Send us a message" page with 8 asp:TextBoxes on the page (where the user enters the name, address, phone, email, message, etc.). Then he clicks on submit, the Onclick message handler in code-behind sends an email to some administrator, and all the form fields the user filled in should be emptied and he gets a notification in a label ("Message sent blabla..."). I want to have the form fields cleared to avoid that the user clicks again on submit and the same message is sent a second time.

Answer 1

You need only write a fork for each type of control unless one of the control has something special that needs to be done to reset it.

foreach( var control in this.Controls )
{
    var textbox = control as TextBox;
    if (textbox != null)
        textbox.Text = string.Empty;

    var dropDownList = control as DropDownList;
    if (dropDownList != null)
        dropDownList.SelectedIndex = 0;
    ...
}

ADDITION You asked how to clear controls even ones that are buried. To do that, you should create a recursive routine like so:

private void ClearControl( Control control )
{
    var textbox = control as TextBox;
    if (textbox != null)
        textbox.Text = string.Empty;

    var dropDownList = control as DropDownList;
    if (dropDownList != null)
        dropDownList.SelectedIndex = 0;
    ...

    foreach( Control childControl in control.Controls )
    {
        ClearControl( childControl );
    }
}

So, you would call this by passing the page:

ClearControls( this );

Answer 2

For your scenario the easiest way to clear the fields, in my opinion, is to turn off the ViewState (EnableViewState=false) of the controls you want to appear blank after the submit.

Or perhaps for the whole page unless there is some state you need.