【IOS开发】UItextfield输入电话号码，自动调整格式

UItextfield中实现输入电话号码，自动按位置在加“—”效果。效果图如下。

核心代码：

-(BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range
                                                      replacementString:(NSString *)string
{
    if (range.location == ) {
        return NO;
    }else if (range.location == ){

        NSMutableString *str = [[NSMutableString alloc] initWithString:phoneField.text];
        NSRange range = [str rangeOfString:@"-"];
        if (range.location!=NSNotFound)
        {

        }else {
             [str insertString:@"-" atIndex:];
             [str insertString:@"-" atIndex:];
             phoneField.text = str;
        }
        return YES;
    }else if(range.location==) {
        NSMutableString *str = [[NSMutableString alloc] initWithString:phoneField.text];
        NSString *str1;
        str1 = [str stringByReplacingOccurrencesOfString:@"-"withString:@""];
        phoneField.text = str1;
        return YES;

    }else
    {
        return YES;
    }

}