Why are my "tel:" links not working

I have a tableView which has cells with phone numbers. The app is not dialing the numbers though. See the code below

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
 if (indexPath.section == 2) {
  UITableViewCell *selectedCell = [tableView cellForRowAtIndexPath:indexPath];
  NSString *numberToDial = [NSString stringWithFormat:@"tel:%@", selectedCell.detailTextLabel.text];

  NSLog(@"%@",numberToDial);

  [[UIApplication sharedApplication] openURL:[NSURL URLWithString:numberToDial]];
 }
}

Console ouput: 2010-03-08 01:32:30.830 AIB[1217:207] tel:01 8350098

As you can see, the number goes to the console, but doesn't get dialled. The weird thing is, if I change the last statement to this:

[[UIApplication sharedApplication] openURL:[NSURL URLWithString:@"tel:171"]];

the phone dials the number 171 without any issue

The solution to my particular problem is, as suggested below, to remove the spaces from the phone numbers. I achieved this as follows:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
    if (indexPath.section == 2) {
        UIT开发者_如何学JAVAableViewCell *selectedCell = [tableView cellForRowAtIndexPath:indexPath];
        NSMutableString *numberToDial = [NSMutableString stringWithFormat:@"tel:%@", selectedCell.detailTextLabel.text];

        [numberToDial replaceOccurrencesOfString:@" " 
                                      withString:@"" 
                                         options:NSLiteralSearch 
                                           range:NSMakeRange(0, [numberToDial length])];

        [[UIApplication sharedApplication] openURL:[NSURL URLWithString:numberToDial]];
    }
}

You will need to sanitize the user input for it to be a valid tel:// URL. Specifically this includes stripping of:

• Spaces
• Hashes (#)
• Asterisks(*)

From iPhone Dev Center:

To prevent users from maliciously redirecting phone calls or changing the behavior of a phone or account, the Phone application supports most, but not all, of the special characters in the tel scheme. Specifically, if a URL contains the * or # characters, the Phone application does not attempt to dial the corresponding phone number.

From URLs for URLs for Telephone Calls RFC:

...spaces MUST NOT be used in phone numbers in URLs as the space character cannot be used in URLs without escaping it.

You need to escape spaces with for example NSString's stringByAddingPercentEscapesUsingEncoding: method.

You can't have a space in the phone number. Strip that out and try again.

St3fan is right, you should use stringByAddingPercentEscapesUsingEncoding before constructing NSURL instance. iPhone OS does other magic automatically for you. If you will not percent escape problem characters then URLWithString: method will return nil.