在UITextfield中使用逗号分隔自动建议

Question

下面的代码让我自动建议输入到UITextfield中的值,方法是将它与先前添加的字符串对象的数组进行比较,并在UITableview中显示它.这很好,但只适用于一个单词.

那么现在,我可以用这样的方式修改代码,即在用户输入逗号后再开始输入,我可以再次搜索相同的字符串数组以获取逗号后输入的字符的建议吗？

- (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];
}

Answer 1

你可以这样做,

- (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;
}

这种方法有点像,

• componentsSeparatedByString分隔textFields文本,并将其作为一个NSArray
• lastObject从该数组中获取最后一个对象.如果是@""则不搜索否则搜索匹配元素.

希望这会帮助你.