从NSAttributed字符串中提取UIImage

Question

我正在做的是：

1. NSATTRIBUTE字符串=NSSTRING+UIIMAGE
2. NSDATA=未分配字符串
3. 此外，我还能够将nsdata转换为非贡献字符串
4. 未分配字符串=NSDATA：
5. 然后从NSAttributed字符串中提取嵌套
6. NSSTRING=[NATTRIBUTED字符串]

查询：

如何从NSATTRIBUTED字符串中获取图像；

• UIIMAGE=来自NSATTRIBUTED字符串
• ARRAYOFIGE=来自NSATTRIBUTED字符串

Answer 1

您必须枚举NSAttributedString以查找NSTextAttachment s。

NSMutableArray *imagesArray = [[NSMutableArray alloc] init];
[attributedString enumerateAttribute:NSAttachmentAttributeName
                             inRange:NSMakeRange(0, [attributedString length])
                             options:0
                          usingBlock:^(id value, NSRange range, BOOL *stop)
{
    if ([value isKindOfClass:[NSTextAttachment class]])
    {
    NSTextAttachment *attachment = (NSTextAttachment *)value;
    UIImage *image = nil;
    if ([attachment image])
        image = [attachment image];
    else
        image = [attachment imageForBounds:[attachment bounds]
                             textContainer:nil
                            characterIndex:range.location];
    if (image)
        [imagesArray addObject:image];
    }
}];

正如您所看到的，有一个测试if ([attachment image])。这是因为如果你创建了NSTextAttachment来放置NSAttachmentAttributeName，它就会存在，你的图像也会存在。但是，例如，如果您使用来自web的图像，并将其从HTML代码转换为NSTextAttachment，那么[attachment image]将为零，您将无法获得图像。

您可以看到在这个片段中使用断点（通过设置真实图像URL和捆绑包中的真实图像名称）。NSString*htmlString=@"http://anImageURL\">Blahttp://anOtherImageURL\">测试重新测试"；

NSError *error;
NSAttributedString *attributedStringFromHTML = [[NSAttributedString alloc] initWithData:[htmlString dataUsingEncoding:NSUTF8StringEncoding]
                                                                                options:@{NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType,
                                                                                          NSCharacterEncodingDocumentAttribute:@(NSUTF8StringEncoding)}
                                                                     documentAttributes:nil
                                                                                  error:&error];
NSTextAttachment *textAttachment = [[NSTextAttachment alloc] init];
[textAttachment setImage:[UIImage imageNamed:@"anImageNameFromYourBundle"]];
NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithAttributedString:attributedStringFromHTML];
[attributedString appendAttributedString:[NSAttributedString attributedStringWithAttachment:textAttachment]];

Answer 2

在Swift 3中：（此处与macOS等效）

func textViewDidChange(_ textView: UITextView) {
    // other code...
    let range = NSRange(location: 0, length: textView.attributedText.length)
    if (textView.textStorage.containsAttachments(in: range)) {
        let attrString = textView.attributedText
        var location = 0
        while location < range.length {
            var r = NSRange()
            let attrDictionary = attrString?.attributes(at: location, effectiveRange: &r)
            if attrDictionary != nil {
                // Swift.print(attrDictionary!)
                let attachment = attrDictionary![NSAttachmentAttributeName] as? NSTextAttachment
                if attachment != nil {
                    if attachment!.image != nil {
                        // your code to use attachment!.image as appropriate
                    }
                }
                location += r.length
            }
        }
    }
}

Answer 3

我将代码Larme转换为swift 3

      var imagesArray = [Any]()
      textView.attributedText.enumerateAttribute(NSAttachmentAttributeName, in: NSRange(location: 0, length: textView.attributedText.length), options: [], using: {(value,range,stop) -> Void in
            if (value is NSTextAttachment) {
                let attachment: NSTextAttachment? = (value as? NSTextAttachment)
                var image: UIImage? = nil
                if ((attachment?.image) != nil) {
                    image = attachment?.image 
                } else {
                    image = attachment?.image(forBounds: (attachment?.bounds)!, textContainer: nil, characterIndex: range.location)
                }
                if image != nil {
                  imagesArray.append(image)
                }
            }
        })