How to simulate the delete key on UITextField?

Question

Hi,

I'm creating an application on the iPad. I create a custom keyboard using UITextField's inputView property. To insert text at the cursor position, I use the copy & paste method (http://dev.ragfield.com/2009/09/insert-text-at-current-cursor-location.html), which works fine. Now, I want to create the delete key. The code that I'm using is:

if (textField.text.length > 0) {
    textField.text = [textField.text substringToIndex:textField.text.length-1];
}

However, as you may know, it only deletes the last character no matter where the cursor is. Does anyone know a better solution?

Thank you very much!

Answer 1

Consider switching to a UITextView, which has a selectedRange property for getting the currently selected range of characters or the cursor location if nothing is selected. Unfortunately, UITextField does not have this method, and I have not found another way to find the cursor location.

The documentation for the selectedRange property can be found here here on Apple's website. It consists of an NSRange in which selectedRange.location is the cursor location and selectedRange.length is the number of selected characters (or zero if nothing is selected.) Your code will have to look something like this:

textView.text = [textView.text stringByReplacingCharactersInRange:textView.selectedRange withString:@""];

Answer 2

A UITextView has a selectedRange property. Given that you could build a range to use with the following code:

textView.text = [textView.text stringByReplacingCharactersInRange:?? withString:@""];

A UITextField has no such range property. Obviously it has a _selectionRange member but that is private.

I think your choices are either to switch to a UITextView or prevent having the cursor anywhere but at the end of the text and using your current code.

You can always submit a bug report to Apple requesting that they document selectedRange for UITextField, or ask for special permission to access the field directly.