如何檢測UITextView中的圖像刪除

Question

如果我將圖像添加到UITextView中，如下所示：

NSTextAttachment *textAttachment = [[NSTextAttachment alloc] init];
textAttachment.image = image;

NSAttributedString *attrStringWithImage = [NSAttributedString attributedStringWithAttachment:textAttachment];
[myString appendAttributedString:attrStringWithImage];

self.inputTextView.attributedText = myString;

之后如何通過用戶點擊鍵盤上的后退按鈕來檢測圖像是否已被刪除？

我會用下面的嗎？

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text

如果是這樣，怎么樣？

Answer 1

我這樣做了：

- (BOOL)textView:(UITextView *)textView shouldChangeTextInRange:(NSRange)range replacementText:(NSString *)text{
[self.textView.attributedText enumerateAttribute:NSAttachmentAttributeName
                        inRange:NSMakeRange(0, self.textView.attributedText.length)
                        options:0
                     usingBlock:^(id value, NSRange imageRange, BOOL *stop){
     if (NSEqualRanges(range, imageRange) && [text isEqualToString:@""]){
         //Wants to delete attached image
     }else{
         //Wants to delete text
     }

  }];
return YES;
}

希望，能幫到你！

Answer 2

使用swift，這是我從UITextView中刪除圖像（添加為NSTextAttachment）的方法：

func textView(textView: UITextView, shouldChangeTextInRange range: NSRange, replacementText text: String) -> Bool {

    // empty text means backspace
    if text.isEmpty {
        textView.attributedText.enumerateAttribute(NSAttachmentAttributeName, inRange: NSMakeRange(0, textView.attributedText.length), options: NSAttributedStringEnumerationOptions(rawValue: 0)) { [weak self] (object, imageRange, stop) in

            if NSEqualRanges(range, imageRange) {
                self?.attributedText.replaceCharactersInRange(imageRange, withString: "")
            }
        }
    }

    return true
}