Question

我有一个基于TextKit的编辑器，支持添加图像。我想在不同的行上显示每个图像。

我的代码看起来像这样（谢谢TextEdit），在我的NSTextStorage的子类中

- (void)addImageAssets:(NSArray *)allAssets atRange:(NSRange)range;
{

    NSMutableAttributedString *attachments = [NSMutableAttributedString new];

    NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
        paragraphStyle.alignment = NSTextAlignmentCenter;
    paragraphStyle.lineSpacing = 20.0f;

    for (ALAsset *newAsset in allAssets)
    {
        UIImage *theImage = [UIImage imageWithCGImage:newAsset.aspectRatioThumbnail];

        NSTextAttachment *textAttachment = [NSTextAttachment new];
        textAttachment.image = theImage;

        NSMutableAttributedString *replacementString = [NSMutableAttributedString new];
        [replacementString appendAttributedString:[NSAttributedString attributedStringWithAttachment:textAttachment]];
        [replacementString addAttribute:NSParagraphStyleAttributeName
                                  value:paragraphStyle
                                  range:NSMakeRange(0, [replacementString length])];

        [attachments appendAttributedString:replacementString];
    }

    _isEditing = YES;
    [self beginEditing];

    [_backingStore replaceCharactersInRange:range
                       withAttributedString:attachments];

    [self edited:NSTextStorageEditedAttributes
           range:range changeInLength:allAssets.count];
    [super processEditing];


    [self endEditing];
    _isEditing = NO;
}

（_ isEditing是一个用于记账的布尔标志）

输出看起来像Output http://take.ms/QCvRK

我在NSMutableParagraphStyle上尝试了各种参数，但在每张图片后我都无法换行。

在文字附件旁边附加换行符（＆＃34; \ r＆＃34;）会导致字形错误

  !!! _NSLayoutTreeLineFragmentRectForGlyphAtIndex invalid glyph index 1
  !!! _NSGlyphTreeInvalidateGlyphsForCharacterRange invalid char range 1
  !!! _NSGlyphTreeInvalidateGlyphsForCharacterRange character count mismatch
  !!! _NSLayoutTreeLineFragmentRectForGlyphAtIndex invalid glyph index 0
  !!! _NSLayoutTreeLineFragmentRectForGlyphAtIndex invalid glyph index 0
  !!! _NSLayoutTreeLineFragmentUsedRectForGlyphAtIndex invalid glyph index 2147483647

我尝试将 NSTextAttachment 子类化为覆盖 attachmentBoundsForTextContainer：proposedLineFragment：glyphPosition：characterIndex：，以便将宽度设置为设备宽度，这导致所附的图像看起来很破旧。

关于如何在每张图片后立即引入换行符的任何建议？如果我能让文本在图像附件中流动，那也很棒。

提前致谢。

NSTextAttachment，文本在它周围流动

0 个答案: