更新 NSTextStorage 字体时崩溃

Question

我的UITextView响应UIContentSizeCategoryDidChangeNotification响应动态字体变化，我实现了如下代码：

 NSTextStorage * textStorage = [self textStorage];
[textStorage beginEditing];
[textStorage enumerateAttribute: NSFontAttributeName
                        inRange: NSMakeRange(0, [textStorage length])
                        options: 0
                     usingBlock: ^(id value, NSRange range, BOOL * stop) {
                         UIFont *newFont = [UIFont fontWithDescriptor: [UIFontDescriptor preferredFixedFontDescriptorWithTextStyle: IDFontTextStyleFixed] size: 0.0f];

                         if (newFont) {
                             [textStorage removeAttribute: NSFontAttributeName
                                                    range: range];
                             [textStorage addAttribute: NSFontAttributeName
                                                 value: newFont
                                                 range: range];
                         }
                     }];

[textStorage endEditing];

它总是在最后一行崩溃，[textStorage endEditing];。我已启用异常断点，~~但调试窗格中没有其他信息~~请参阅下面的回溯。如果我删除 'beginEditing 和 endEditing，它会在 removeAttribute 行崩溃。我在我的整个应用程序中使用 [UIFont fontWithDescriptor: [UIFontDescriptor preferredFixedFontDescriptorWithTextStyle: IDFontTextStyleFixed] size: 0.0f];，它在任何地方都有效，除了 UITextView.

有人看到出了什么问题以及我该如何解决吗？

编辑：这是回溯：

    (lldb) bt
* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=2, address=0x10f3c0060)
    frame #0: 0x000000010c77f29d libobjc.A.dylib`realizeClass(objc_class*) + 145
    frame #1: 0x000000010c783125 libobjc.A.dylib`lookUpImpOrForward + 127
    frame #2: 0x000000010c792554 libobjc.A.dylib`_objc_msgSend_uncached + 68
    frame #3: 0x0000000118d39ce7 UIFoundation`-[NSGlyphGenerator generateGlyphsForGlyphStorage:desiredNumberOfCharacters:glyphIndex:characterIndex:] + 251
    frame #4: 0x0000000118d06d47 UIFoundation`-[NSLayoutManager(NSPrivate) _fillGlyphHoleForCharacterRange:startGlyphIndex:desiredNumberOfCharacters:] + 736
    frame #5: 0x0000000118d091b0 UIFoundation`_NSFastFillAllGlyphHolesForCharacterRange + 726
    frame #6: 0x0000000118d47f2e UIFoundation`-[NSLayoutManager glyphRangeForCharacterRange:actualCharacterRange:] + 64
    frame #7: 0x0000000118d071af UIFoundation`-[NSLayoutManager(NSPrivate) _fillLayoutHoleForCharacterRange:desiredNumberOfLines:isSoft:] + 617
    frame #8: 0x0000000118d08e9a UIFoundation`-[NSLayoutManager(NSPrivate) _fillLayoutHoleAtIndex:desiredNumberOfLines:] + 208
    frame #9: 0x0000000118d0954a UIFoundation`-[NSLayoutManager(NSPrivate) _markSelfAsDirtyForBackgroundLayout:] + 325
    frame #10: 0x0000000118d13d10 UIFoundation`-[NSLayoutManager(NSPrivate) _invalidateLayoutForExtendedCharacterRange:isSoft:invalidateUsage:] + 2212
    frame #11: 0x0000000118d44743 UIFoundation`-[NSLayoutManager textStorage:edited:range:changeInLength:invalidatedRange:] + 226
    frame #12: 0x0000000118d448f9 UIFoundation`-[NSLayoutManager processEditingForTextStorage:edited:range:changeInLength:invalidatedRange:] + 47
    frame #13: 0x0000000118d6c216 UIFoundation`-[NSTextStorage _notifyEdited:range:changeInLength:invalidatedRange:] + 168
    frame #14: 0x0000000118d6bd4c UIFoundation`-[NSTextStorage processEditing] + 372
    frame #15: 0x0000000118d6b995 UIFoundation`-[NSTextStorage endEditing] + 83
  * frame #16: 0x000000010bee435b MyApp`-[MyUITextView updateFonts](self=0x00007fc26208c000, _cmd="updateFonts") at MyUITextView.m:107

Answer 1

好的，我解决了

我正在使用助手 class 来处理 NSTextStorage、NSTextContainer 和 NSLayoutManager 对象。在创建MyTextView时，我没有坚持helper对象（我只将textContainer传递给了MyTextView的init。我现在将辅助对象设为 MyTextView 的 @property，因此它具有很强的引用，并且崩溃消失了。

更新 NSTextStorage 字体时崩溃

Crash when updating NSTextStorage font

objective-c

ios

nstextstorage