ios - 自动建议在UITextfield中使用逗号分隔

Question

下面的代码让我通过将其与以前添加的字符串对象数组进行比较并在UITableview中显示它，来自动建议键入到UITextfield中的值。
这很好用，但仅适用于单个单词。

所以现在，我可以用这样的方式修改代码，即在用户输入逗号之后，再次开始输入时，我可以再次搜索相同的字符串数组以获取建议，以查找在逗号之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

- (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;
}

这种方法的工作原理是，

componentsSeparatedByString用和分隔textFields文本，并将其作为NSArray

lastObject从该数组中获取最后一个对象。如果它是@“”，则不进行搜索，否则搜索匹配的元素。

希望这会帮助你。