Custom keyboard iphone , having problem with backspace button in UITextView

Question

Hey Guys check this code ( My Custom Keyboard) :

-(IBAction) updateTextBackSpace:(id)sender
{
    if([txtview.text length]>0)
    {
        NSString *deletedLastCharString = [txtview.text substringToIndex:([txtview.text length]-1)];
        [txtview setText:deletedLastCharString];
    }
    else
    {
        return nil;
    }
}  

The thing is that I can't figure out how to change this code so that , I can erase any text in any give line at the cursor, the backspace starts to erase from end of the line .I should be able to erase(backspace) from the cursor location Please Help

Answer 1

replace this

NSString *deletedLastCharString = [txtview.text substringToIndex:([txtview.text length]-1)];

with

NSRange range  = [txtview selectedRange];
NSString *deletedLastCharString = [txtview.text substringToIndex:([range.location]-1)];