将NSTextContainer / NSLayoutManager与UITextView一起使用时，文本会出现乱码(Text garbled when using NSTextContainer/NSLayoutManager with UITextView)

 我正在实现分页文本，所以我使用NSLayoutManager和NSTextContainer为每个页面创建UITextViews。 分页工作正常，但文本是乱码。 在vanilla UITextView上设置相同的NSTextStorage时，它看起来是正确的： 
 
// In the class that creates the pages
...
self.textStorage = [[NSTextStorage alloc] initWithString:string attributes:@{}];
self.layoutManager.textStorage = self.textStorage;
....

- (void)createPages{
    // Remove all current text containers
    while (self.layoutManager.textContainers.count > 0){
        [self.layoutManager removeTextContainerAtIndex:0];
    }
    NSMutableArray *textContainers = [NSMutableArray array];
    NSUInteger lastRenderedGlyph = 0;
    while (lastRenderedGlyph < self.layoutManager.numberOfGlyphs){
        NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:self.pageSize];
        [self.layoutManager addTextContainer:textContainer];
        [textContainers addObject:textContainer];
        [self addDummyContainersForNewlinesAfterContainer:textContainer];
        NSRange range = [self.layoutManager glyphRangeForTextContainer:textContainer];
        lastRenderedGlyph = NSMaxRange(range);
    }
    self.textContainers = textContainers;
}

// In my ViewController
- (void)addTextViews{
    self.scrollView = [[UIScrollView alloc] initWithFrame:self.view.bounds];
    self.scrollView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    self.scrollView.backgroundColor = [UIColor lightGrayColor];
    [self.view addSubview:self.scrollView];
    CGFloat xOffset = 0;
    // Option #1 - This results in garbled text
    for (NSTextContainer *textContainer in self.coordinator.textContainers){
        break;
        CGRect frame = CGRectMake(xOffset, 0, self.coordinator.pageSize.width, self.coordinator.pageSize.height);
        xOffset = CGRectGetMaxX(frame)+1;
        self.scrollView.contentSize = CGSizeMake(xOffset, self.coordinator.pageSize.width);
        UITextView *textView = [[UITextView alloc] initWithFrame:frame textContainer:textContainer];
        textView.attributedText = self.coordinator.textStorage;
        [self.scrollView addSubview:textView];
    }
    // Option #2 - This does not result in garbled text
    UITextView *textView = [[UITextView alloc] initWithFrame:self.view.bounds];
    [self.view addSubview:textView];
    textView.attributedText = self.coordinator.textStorage;
}
 
   

I'm implementing paged text and so I'm using NSLayoutManager and NSTextContainer to create UITextViews for each page. The paging is working fine, but the text is garbled. When setting the same NSTextStorage on a vanilla UITextView it appears correct:
 
// In the class that creates the pages
...
self.textStorage = [[NSTextStorage alloc] initWithString:string attributes:@{}];
self.layoutManager.textStorage = self.textStorage;
....

- (void)createPages{
    // Remove all current text containers
    while (self.layoutManager.textContainers.count > 0){
        [self.layoutManager removeTextContainerAtIndex:0];
    }
    NSMutableArray *textContainers = [NSMutableArray array];
    NSUInteger lastRenderedGlyph = 0;
    while (lastRenderedGlyph < self.layoutManager.numberOfGlyphs){
        NSTextContainer *textContainer = [[NSTextContainer alloc] initWithSize:self.pageSize];
        [self.layoutManager addTextContainer:textContainer];
        [textContainers addObject:textContainer];
        [self addDummyContainersForNewlinesAfterContainer:textContainer];
        NSRange range = [self.layoutManager glyphRangeForTextContainer:textContainer];
        lastRenderedGlyph = NSMaxRange(range);
    }
    self.textContainers = textContainers;
}

// In my ViewController
- (void)addTextViews{
    self.scrollView = [[UIScrollView alloc] initWithFrame:self.view.bounds];
    self.scrollView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    self.scrollView.backgroundColor = [UIColor lightGrayColor];
    [self.view addSubview:self.scrollView];
    CGFloat xOffset = 0;
    // Option #1 - This results in garbled text
    for (NSTextContainer *textContainer in self.coordinator.textContainers){
        break;
        CGRect frame = CGRectMake(xOffset, 0, self.coordinator.pageSize.width, self.coordinator.pageSize.height);
        xOffset = CGRectGetMaxX(frame)+1;
        self.scrollView.contentSize = CGSizeMake(xOffset, self.coordinator.pageSize.width);
        UITextView *textView = [[UITextView alloc] initWithFrame:frame textContainer:textContainer];
        textView.attributedText = self.coordinator.textStorage;
        [self.scrollView addSubview:textView];
    }
    // Option #2 - This does not result in garbled text
    UITextView *textView = [[UITextView alloc] initWithFrame:self.view.bounds];
    [self.view addSubview:textView];
    textView.attributedText = self.coordinator.textStorage;
}
 
 

原文：https://stackoverflow.com/questions/35157135