从 NSAttributedString 中提取图像

我正在做的是：

1. NSATTRIBUTE 字符串 = NSSTRING + UIIMAGE's;
2. NSDATA = NSATTRIBUTED 字符串；
3. 我还可以将 nsdata 转换为 nsattributed 字符串
4. NSATTRIBUTEDSTRING = NSDATA：
5. 然后从 NSAttributedstring 中提取嵌套
6. NSSTRING = [NSATTRIBUTED STRING 字符串];

Query:

我如何从 NSATTRIBUTEDSTRING 获取图像；

• UIIMAGE = 来自 NSATTRIBUTEDSTRING；
• 图像数组 = 来自 NSATTRIBUTEDSTRING；

你必须枚举NSAttributedString寻找NSTextAttachments.

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];
    }
}];

正如你所看到的，有一个测试if ([attachment image])。那是因为看起来如果你创建了NSTextAttachment与NSAttachmentAttributeName它会存在，你的形象也会在那里。但是，如果您使用来自网络的图像并将其转换为NSTextAttachment从 HTML 代码，然后[attachment image]将为零，您将无法获取图像。

您可以看到在此代码段中使用断点（通过设置真实图像 URL 和bundle 中的真实图像名称）。 NSString *htmlString = @"http://anImageURL\">Blahttp://anOtherImageURL\"> 测试retest";

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]];