Insert string at cursor position of UITextField

Question

Hello, I've got a few UITextFields in an UITableView. The user should be able to insert only numbers and dots. To do this, I set the keyboard type to UIKeyboardTypeNumberPad and added a '.'-Button at the bottom left corner. Every time the button is pressed, a function is called. This function should insert a dot at the current cursor position, but this is the problem: UITextField hasn't got an selectedRange property, so I'm not able to get the current cursor position. Does anybody know how to solve this problem or is there any other way to do this? Thanks.

Answer 1

Read the value of the text field as a string when your button is pressed. Edit the string and then set the value of the field to the new string.

Answer 2

If you're looking to create text fields that allow you to enter decimal places may I suggest that you rather fix the decimal point to a certain precision and allow the user to enter numbers as follows:

Assuming your precision is 2 decimal points:

start: value is 0.00
user enters 1: value is 0.01
user enters 2: value is 0.12
user enters 3: value is 1.23
user enters 4: value is 12.34

See http://stackoverflow.com/questions/276382/best-way-to-enter-numeric-values-with-decimal-points for a similar solution for currency.

It is by far a more simple solution than creating a custom keyboard and dealing with all the nuances that that approach presents. If, however, you need variable length precision then that approach might suite you better.

Answer 3

I've finally found a solution for this problem! You can put the text you need inserted into the system pasteboard and then paste it at the current cursor position:

[myTextField paste:self]

I found the solution on this person's blog:
http://dev.ragfield.com/2009/09/insert-text-at-current-cursor-location.html

The paste functionality is OS V3.0 specific, but I've tested it and it works fine for me with a custom keyboard.