在文本视图中的属性字符串末尾添加一个 nsstring iOS

Question

我有一个像“Hello There”这样的文本，它将是一个带有红色的属性字符串。然后在该属性字符串的末尾我想附加一个 nsstring 'Who are you?' 但是每当我附加一个 nsstring 时，整个字符串都会变成正常的 nsstring 并且属性字符串的 属性 被删除。我目前的尝试：

NSMutableAttributedString *attributeString = [[NSMutableAttributedString alloc] initWithString:@"Hello There"];
[attributeString addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0,[attributeString length])];

NSMutableAttributedString *previousAttrString = [[NSMutableAttributedString alloc] initWithString:messageTextView.text];

[previousAttrString insertAttributedString: attributeString atIndex:location];
messageTextView.attributedText = previousAttrString;
messageTextView.font = [UIFont fontWithName:@"Helvetica" size:15];

NSString *messageWithContact = [NSString stringWithFormat: @"%@ %@", messageTextView.text, @"Who are you?"];
messageTextView.text=messageWithContact;

我做错了什么？请帮助我。

Answer 1

替换底线

NSString *messageWithContact = [NSString stringWithFormat: @"%@ %@", messageTextView.text, @"Who are you?"];
messageTextView.text=messageWithContact;

和

NSMutableAttributedString *newString = messageTextView.attibutedText;
[newString appendAttributedString: [[NSAttributedString alloc] initWithString: @"Who are you?"];
messageTextView.attibutedText = newString;