相关疑难解决方法(0)

我想做一个UITextField,它有一个静态前缀,用户不能编辑或删除,同时也用浅灰色字体颜色.

文本字段的可编辑部分应始终以黑色显示.

下面给出一个例子:

它主要用于输入用户名,带有不断添加前缀的域.

我已经尝试过使用textFieldShouldClear和textField:shouldChangeCharactersInRange:replacementString:委托方法NSMutableAttributedString,但是根本无法解决它:

- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string
{
    NSMutableAttributedString *text = [textField.attributedText mutableCopy];

    [text addAttribute:NSForegroundColorAttributeName value:[UIColor grayColor] range:NSMakeRange(0, 7)];

    if (textField.text.length > 7)
    {    
        [text addAttribute:NSForegroundColorAttributeName value:[UIColor blackColor] range:NSMakeRange(7, textField.attributedText.length - 7)];
    }
    [text addAttribute:NSFontAttributeName value:[UIFont gothamFontForSize:textField.font.pointSize andWeight:kGothamLight] range:NSMakeRange(0, textField.attributedText.length)];


    return range.location > 6;
}

- (BOOL)textFieldShouldClear:(UITextField *)textField
{
    NSMutableAttributedString *text = [[NSMutableAttributedString alloc] initWithString:@"kombit\\"];
    [text addAttribute:NSForegroundColorAttributeName value:[UIColor grayColor] range:NSMakeRange(0, 7)];
    [text addAttribute:NSFontAttributeName value:[UIFont gothamFontForSize:textField.font.pointSize andWeight:kGothamLight] …