如何防止 UIView 调整大小以适应 ScrollView 高度（自动调整大小已禁用）？

Question

我正在使用 vfr-reader 库编写 PDF 阅读器。为了横向显示两个页面，我将每个页面渲染到自己的视图中，然后将这两个视图添加到容器视图中，然后将容器视图添加到滚动视图中。每个视图的 autoresizingMask 设置为 UIViewAutoresizingNone，contentMode 为 UIViewContentModeRedraw，所有视图的 autoresizingSubviews 设置为“NO”。

但容器视图仍然以某种方式自动调整大小以适应滚动视图的高度，而且我不知道这种情况发生在哪里。我关心这一点，因为当自动调整容器视图大小时，它的宽度变得大于屏幕宽度，并且我无法通过一次滑动滚动到接下来的两页（需要两次滑动），这很糟糕。我缺少什么？

编辑如果有帮助的话会添加一些。在 ViewController 中，我使用以下选项创建一个滚动视图：

theScrollView = [[ReaderScrollView alloc] initWithFrame:viewRect];
theScrollView.scrollsToTop = NO;
theScrollView.pagingEnabled = YES;
theScrollView.delaysContentTouches = NO;
theScrollView.showsVerticalScrollIndicator = NO;
theScrollView.showsHorizontalScrollIndicator = NO;
theScrollView.contentMode = UIViewContentModeRedraw;
theScrollView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
theScrollView.backgroundColor = [UIColor clearColor];
theScrollView.userInteractionEnabled = YES;
theScrollView.autoresizesSubviews = NO;
theScrollView.delegate = self;
[self.view addSubview:theScrollView];

当我绘制页面时，我将一个 UIView 添加到滚动视图，该滚动视图以这种方式启动：

if ((self = [super initWithFrame:frame]))
{
    self.autoresizesSubviews = YES;
    self.userInteractionEnabled = YES;
    self.contentMode = UIViewContentModeRedraw;
    self.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;       
    self.backgroundColor = [UIColor clearColor];

    theScrollView = [[ReaderScrollView alloc] initWithFrame:self.bounds]; // Not sure about this part - why is the 2nd scroll view added?
// this is the way its done in vfr reader

    theScrollView.scrollsToTop = NO;
    theScrollView.delaysContentTouches = NO;
    theScrollView.showsVerticalScrollIndicator = NO;
    theScrollView.showsHorizontalScrollIndicator = NO;
    theScrollView.contentMode = UIViewContentModeRedraw;
    theScrollView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    theScrollView.backgroundColor = [UIColor clearColor];
    theScrollView.userInteractionEnabled = YES;
    theScrollView.autoresizesSubviews = NO;
    theScrollView.bouncesZoom = YES;
    theScrollView.delegate = self;

    theContentView = [[ReaderContentPage alloc] initWithURL:fileURL page:page password:phrase landscape:(BOOL)isLandscape position:FALSE];
    CGRect viewRect = CGRectZero;
    viewRect.size.width = theContentView.bounds.size.width;
    viewRect.size.height = theContentView.bounds.size.height;    


    if( isLandscape){
        NSLog(@"Landscape detected in content view");
        if (theContentView == NULL)
        {
            theContentView = [[ReaderContentPage alloc] initWithURL:fileURL page:(page+1) password:phrase landscape:(BOOL)isLandscape position:FALSE];
            theContentView2 = NULL;
            viewRect.size.width = theContentView.bounds.size.width;
            viewRect.size.height = theContentView.bounds.size.height;    
        } else {
            if (page == 1)
                theContentView2 = NULL;
            else
                theContentView2 = [[ReaderContentPage alloc] initWithURL:fileURL page:(page+1) password:phrase landscape:(BOOL)isLandscape position:TRUE];
            if (theContentView2 != NULL)
               viewRect.size.width = theContentView.bounds.size.width*2;
        }            

    }       
    if (theContentView != nil) // Must have a valid and initialized content view
    {

        theContainerView = [[UIView alloc] initWithFrame:viewRect];


        theContainerView.autoresizesSubviews = NO;
        theContainerView.userInteractionEnabled = NO;
        theContainerView.contentMode = UIViewContentModeRedraw;            
        theContainerView.autoresizingMask = UIViewAutoresizingNone;
        theContainerView.backgroundColor = [UIColor whiteColor];


        theScrollView.contentSize = theContentView.bounds.size; // Content size same as view size


        theScrollView.contentOffset = CGPointMake((0.0f - CONTENT_INSET), (0.0f - CONTENT_INSET));
        theScrollView.contentInset = UIEdgeInsetsMake(CONTENT_INSET, CONTENT_INSET, CONTENT_INSET, CONTENT_INSET);

        theThumbView = [[ReaderContentThumb alloc] initWithFrame:theContentView.bounds]; // Page thumb view           

        [theContainerView addSubview:theThumbView]; // Add the thumb view to the container view

        [theContainerView addSubview:theContentView]; // Add the content view to the container view

        if(( isLandscape) && (theContentView2 != NULL)){            
             [theContainerView addSubview:theContentView2]; // Add the content view to the container view

        }           



        [theScrollView addSubview:theContainerView]; // Add the container view to the scroll view

        [self updateMinimumMaximumZoom]; // Update the minimum and maximum zoom scales

        theScrollView.zoomScale = theScrollView.minimumZoomScale; // Zoom to fit
    }

    [self addSubview:theScrollView]; // Add the scroll view to the parent container view   

    [theScrollView addObserver:self forKeyPath:@"frame" options:NSKeyValueObservingOptionNew context:NULL];

    self.tag = page; // Tag the view with the page number
}

return self;

ReaderContentPage 是这样创建的：

if ((self = [super initWithFrame:frame]))
    {
        self.autoresizesSubviews = NO;

        self.userInteractionEnabled = NO;
        self.clearsContextBeforeDrawing = NO;
        self.contentMode = UIViewContentModeRedraw;     
        self.autoresizingMask = UIViewAutoresizingNone;
        self.backgroundColor = [UIColor clearColor];

        view = self; // Return self
    }

Answer 1

在类 ReaderContentView 中的函数 updateMinimumMaximumZoom 中：

计算适合屏幕的缩放比例是在单个视图中完成的，但在横向中应该从 ContainerView 中计算。

尝试将此代码

CGFloat ZoomScale = ZoomScaleThatFits(targetRect.size, theContentView.bounds.size);

替换为

CGFloat ZoomScale = ZoomScaleThatFits(targetRect.size, theContainerView.bounds.size); >

Answer 2

UIScrollView 中有一个 contentMode 属性，将其更改为 UIViewContentModeCenter 或其他内容以防止调整大小。