UITextView: characters count is not right when the backspace is typed in

Question

I want to show the characters number when I type in a UITextView. But I'm confused when I presse the delete/backspace key.

I use:

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text

My code is:

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text
{
    NSLog(@"input %d chars",textView.text.length + 1);
    return YES;
}

When I type in hello, it shows 'input 5 chars'; But if I click the delete/backspace key, the number become 6, not 4. What's the matter with this? How I can know the exact number of chars in the UITextView when I type in?

Answer 1

It's pretty obvious :)

You're outputting the length+1

textView.text.length + 1

but a backspace doesn't make the length 1 longer, it makes it 1 shorter!

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text

    // Do the replacement
    NSString *newText = [textView.text stringByReplacingCharactersInRange:range withString:text];

   // See what comes out
    NSLog(@"input %d chars", newText.length);

    return YES;
}

Answer 2

You can get the text that is going to be in text field after your edit and then check its length:

NSString* newString = [textField1.text stringByReplacingCharactersInRange:range withString:string];
int newLength = [newString length];

Answer 3

The text view sends textView:shouldChangeTextInRange:replacementText: before it actually changes its text.

It sends textViewDidChange: after it changes its text.

So just implement textViewDidChange: instead:

- (void)textViewDidChange:(UITextView *)textView {
    NSLog(@"textView.text.length = %u", textView.text.length);
}

Answer 4

Check the length of the replacement text argument, which will be zero in case of a backspace.

There's another case to consider, where the user selects a range of characters and pastes text into the field. In that case, you should also subtract out the length of the replaced text.

NSLog(@"New length is: %d chars",textView.text.length - range.length + text.length);