How to create a multiline UITextfield?

UITextField is specifically one-line only.

Your Google search is correct, you need to use UITextView instead of UITextField for display and editing of multiline text.

In Interface Builder, add a UITextView where you want it and select the "editable" box. It will be multiline by default.

You can fake a UITextField using UITextView. The problem you'll have is that you lose the place holder functionality.

If you choose to use a UITextView and need the placeholder, do this:

In your viewDidLoad set the color and text to placeholders:

myTxtView.textColor = .lightGray
myTxtView.text = "Type your thoughts here..."

Then make the placeholder disappear when your UITextView is selected:

func textViewDidBeginEditing (textView: UITextView) {
    if myTxtView.textColor.textColor == ph_TextColor && myTxtView.isFirstResponder() {
        myTxtView.text = nil
        myTxtView.textColor = .white
    }
}

When the user finishes editing, ensure there's a value. If there isn't, add the placeholder again:

func textViewDidEndEditing (textView: UITextView) {
    if myTxtView.text.isEmpty || myTxtView.text == "" {
        myTxtView.textColor = .lightGray
        myTxtView.text = "Type your thoughts here..."
    }
}

Other features you might need to fake:

UITextField's often capitalize every letter, you can add that feature to UITableView:

myTxtView.autocapitalizationType = .words

UITextField's don't usually scroll:

myTxtView.scrollEnabled = false

Ok I did it with some trick ;) First build a UITextField and increased it's size like this :

CGRect frameRect = textField.frame;
        frameRect.size.height = 53;
        textField.frame = frameRect;

Then build a UITextView exactly in the same area that u made my UITextField, and deleted its background color. Now it looks like that u have a multiple lines TextField !