how to hide the keyboard when empty area is touched on iphone

Updated way (recommended):

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{
   [self.view endEditing:YES];
}

This will end editing on all subviews and resign the first responder.

Other way (enumerating over all text views):

Here’s a step by step for it:

Add an IBAction to your view controller, such as – (IBAction)backgroundTouch:(id)sender

In the backgroundTouch action, you need to send the resignFirstResponder message to all of the text boxes in your view. This is unfortunate but necessary since there’s currently no way to retrieve the object that currently has FirstResponder status. It should look something like this:

- (IBAction)backgroundTouch:(id)sender {
  [someTextBox resignFirstResponder];
  [anotherTextBox resignFirstResponder];
}

Add a button control to the view, size it to cover the entire visible area (except for the status bar or any tab or navigation controllers). Select the button and then go to the Layout Menu and select Send To Back. Also set the button’s Type to custom, which is invisible if you don’t specifically supply any drawing code for it.

Connect the Button’s Touch Up Inside event to the backgroundTouch: action and try it out.