Auto suggest in UITextfield with comma separation

问题:

The following code lets me auto suggest values typed into a UITextfield, by comparing it to an array of previously added string objects and show it in a UITableview. This works fine, but only for a single word.

So now, can I modify the code in such a way, that after the user enters a comma, then starts typing again, I can search the same string array for suggestions again for the characters typed after the comma?

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string 
{

if (textField.tag == tagTextFieldTag)    //The text field where user types
{
    textField.autocorrectionType = UITextAutocorrectionTypeNo;
    autocompleteTableView.hidden = NO;   //The table which displays the autosuggest

        NSString *substring = [NSString stringWithString:textField.text];

        substring = [substring stringByReplacingCharactersInRange:range withString:string]; 

if ([substring isEqualToString:@""]) 
    {
        autocompleteTableView.hidden = YES; //hide the autosuggest table if textfield is empty
    }
        [self searchAutocompleteEntriesWithSubstring:substring];  //The method that compares the typed values with the pre-loaded string array

    }


return YES;
}

 - (void)searchAutocompleteEntriesWithSubstring:(NSString *)substring {

[autoCompleteTags removeAllObjects];

for(Tag *tag3 in tagListArray)   //tagListArray contains the array of strings

 //tag3 is an object of Tag class, which has a single attribute called 'text'

{
    NSString *currentString = tag3.text;
    NSRange substringRange = [currentString rangeOfString:substring];
    if(substringRange.location ==0)
    {
        [autoCompleteTags addObject:currentString];
    }
}

[autocompleteTableView reloadData];
}

回答1:

You can do it like this,

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string 
{

  if (textField.tag == tagTextFieldTag)    //The text field where user types
  {
    textField.autocorrectionType = UITextAutocorrectionTypeNo;
    autocompleteTableView.hidden = NO;   //The table which displays the autosuggest
    NSArray *autoComplete = [textField.text componentsSeparatedByString:@","];
    NSString *substring = [NSString stringWithString:[autoComplete lastObject]];
   if ([substring isEqualToString:@""]) 
    {
        autocompleteTableView.hidden = YES; //hide the autosuggest table if textfield is empty
    }
        [self searchAutocompleteEntriesWithSubstring:substring];

    }

 return YES;
}

this method works like,

• componentsSeparatedByString seperates the textFields text by , and give it as an NSArray
• lastObject takes the last object from that array. If it is @"" no searching otherwise searches for an matching element.

Hope this will help you.